The use of commercial road vehicles has grown with the recent rapid economic growth in the world, but reckless speeding of these heavy vehicles often results in fatal accidents. The Vehicle Speed Warning System is designed and developed to monitor the vehicle speed and raise an alarm if the vehicle has exceeded the preset speed limit. It consists of in-vehicle subsystem, which is fitted into the vehicle, and peripheral interface subsystem connected to the host computer. The system is designed using MC68HC11E9 micro controller. It allows proper calibration of the in-vehicle subsystem and offline data downloading.
The microcontroller based Vehicle Speed Warning System has been designed and its application software has been developed. The principal objective in designing this warning system is to present and demonstrate the basic concepts of in-vehicle speed detection and wireless data setting and retrieving system, which will serve as a base for future development of vehicle speed monitoring and tracking system.
[Graphics and tables are omitted from this preview]
CHAPTER 1: INTRODUCTION
1.1 Overview
Speeding has been implicated as a major contributing factor in all fatal motor-vehicle crashes. A small increase in traveling speed before braking begins can result in large increases in impact speed and the risk of fatal injury. Even small differences in impact speed will make a large difference to the probability of serious injury. Figure 1.1 shows the risk of a crash at difference speeds relative to travelling at 60 km/h.
From the figure, driving at 65 km/h is twice as likely to have a crash as a driver traveling at 60 km/h, and driving at 70 km/h the driver is more than 4 times as likely to crash. When a driver is speeding, there is less time for both that driver and any other road user to recognize danger, decide on an evasive action (brake) and complete the evasive action.
When a vehicle is traveling with higher speed, the reaction and braking distances are also longer. Figure 1.2 shows the total stopping distance at various speeds. The reaction distance is referred to the distance that a vehicle travels from the time a driver recognizes an emergency until the driver can react, whereas the braking distance is referred to the distance it takes to stop the vehicle. The faster a vehicle travels the more distance it takes to stop the vehicle.
Besides, speeding can lead to higher impact speeds and crash energy as well as are associated with high risk of losing control of the vehicle. The crash severity increases based on the vehicle speed at the time a crash happens. Figure 1.3 shows the impact speed at different traveling speed. When a crash does occur, people are killed or seriously injured only when the impact speed and hence the energy absorbed by the human exceeds the human tolerance to violent forces. The greater the vehicle speed, the greater the chance of death or serious injury. Vehicles and their occupants in motion have kinetic energy that is dissipated in a crash. The greater the energy that must be dissipated during the crash, the greater the chances of severe injury or death. In a collision, the vehicle speed decreases abruptly, while its occupants continue on toward the point of impact. The kinetic energy released equals the weight of the vehicle multiplied by the square of its speed and the energy released will result in injuries. Therefore, the seriousness of a crash depends on the weight of the vehicle but especially on the speed.
Besides that, speeding will reduce driver’s ability to steer safely around curves on the roadway. It is also known that vehicle traveling around a curve or around an object is subject to centrifugal force. Every curve has a critical curve speed and should be taken at the recommended speed or below depending on the conditions. If a vehicle travels faster than the curve is designed for, the driver will break the centrifugal force and the vehicle will start to slide out of the curve sideways, which can lead to a rollover. This becomes more significant when the driver is speeding. Furthermore, higher speed will also reduce the ability of vehicles, safety belts, air bags and barriers to protect vehicle occupants in a crash. Moreover, higher speeds of approaching vehicles are more likely to be misjudged by turning drivers and the consequences of this are more serious.
These factors clearly show that it is important for a vehicle to travel at lower speed and even if a vehicle can not be stopped in the available distance during an emergency, the collision can still sometimes be avoided. With this objective, the Commercial Vehicle Speed Warning System is designed and developed in this project to monitor the vehicle speed and to determine if the vehicle has exceeded the preset speed limit, where the speed limit indicates the maximum speed at which the driver should drive under good road and traffic conditions. After installation of the unit in vehicle, the system is calibrated for proper operation. This unit will give an audible warning, which will alert the driver to impending speeding violations. The driver should then reduce the speed of the vehicle and this will drastically reduce the probability of road accident. The unit also has provision to record the violation and this data can be read by the law enforcement officers for necessary action.
1.2 Background
The design and development idea of this Commercial Vehicle Speed Warning System come from irresponsible and reckless speeding of some commercial vehicles including truck, trailer, lorries and buses, which have resulted in fatal accidents leading to loss of innocent road users lives. There are some factors that lead to these road accidents, such as vehicle overload, atmospheric condition as well as speeding. Since these commercial vehicles have poor braking capability and greater momentum at higher speed, speeding will be considered as a base for the warning system development. Besides that, with large amount of the commercial vehicles operating in country, it is virtually impossible for the authorities to police all these drivers continuously.
There are a number of out-of-vehicle and in-vehicle speed tracking and monitoring technologies with the potential to enhance speed compliance. Since the out-of-vehicle speed tracking device will only make the drivers obey the speed limit just in the speed enforcement zone, the Commercial Vehicle Speed Warning System will focus on the in-vehicle approaches, which will continuously monitor these commercial vehicle speeds at all time and will record the relevant information.
The Commercial Vehicle Speed Warning System consists of two primary subsystems, the in-vehicle subsystem and the peripheral interface subsystem as shown in Figure 1.4. The in-vehicle subsystem is a main control module that will be installed in the commercial vehicle for speed monitoring, where the date, time and total time for speeding when the speeding incident happened will be recorded into the memory, whereas the peripheral interface subsystem is a supporting system to interface and communicate with the in-vehicle subsystem by using wireless communication module, including data setting and retrieving. Once the speeding records in the in-vehicle subsystem memory has been retrieved by the wireless communication module, a host computer can be used to display and analyze the data, providing variable and useful insight into the commercial vehicle's speeding information. Besides that, this warning system is a passive system, that is, it monitors rather than controls the vehicle speed.
1.3 Objectives
The aim of the project is to design a Commercial Vehicle Speed Warning System, which consists of two subsystems, the in-vehicle subsystem and the peripheral interface subsystem. The objectives of this project are as follows:
a) To design a speed warning system (in-vehicle subsystem) that will monitor the vehicle speed and activate an auditory warning as well as record the violation when the preset speed limit is exceeded.
b) A peripheral interface subsystem for remote set-up manipulation and remote data retrieval will be designed. This subsystem provides flexible calibration set-up and has capability to identify which in-vehicle subsystem should be communicated based on identification code programmed into the in-vehicle subsystem.
1.4 Thesis Organization
This report is divided into 5 chapters.
Chapter 1 Introduction gives a brief introduction to Commercial Vehicle Speed Warning System and specifications of project being done. Thesis overview and objectives of the project are also explained briefly.
Chapter 2 Literature Review presents more specific discussions on the speed warning system such as history and classifications of vehicle speed tracking and monitoring systems and definition as well as features and applications of these systems.
Chapter 3 Methodology features the synthesis steps and methodology used to design the Commercial Vehicle Speed Warning System. The tools acquired are listed and the design and development of software and hardware are explained. Majority part of the project is emphasized on the programming and verification.
Chapter 4 Results and Discussion contains the details of the Commercial Vehicle Speed Warning System, including the feature and construction of the warning system. Besides that, the data setting and retrieving process between subsystems of the Commercial Vehicle Speed Warning System are also explained.
Chapter 5 Conclusion is the conclusion being made for the project being done. Apart from that, suggestion of future improvement of this project is discussed.
CHAPTER 2: LITERATURE REVIEW
2.1 Introduction
A number of vehicle speed monitoring and tracking systems exist in the market, most notably the Light Amplification by Simulated Emission of Radiation (LASER) speed gun, Radio Detection and Ranging (RADAR) speed gun, speed camera system and fleet monitoring system. Law enforcement in the last decade has moved increasingly to newer technologies such as Global Positioning System (GPS) based vehicle tracking system to catch speeding motorists and improve road safety as well as for fleet management applications. These newer technologies are likely to supplement rather than replace traditional speed monitoring and tracking systems.
2.2 Vehicle Speed Measurement
2.2.1 Evolution of Speed Sensors
Since the early years of the automobile, a need to monitor vehicle speed has evolved. As vehicle speed increased and roads improved, the main objectives of a speedometer were to allow the driver to accurately view the vehicle speed, possibly to avoid a speeding ticket, and to be able to read the odometer to verify how many miles were on the vehicle. Most speedometers (Jurgen, R. 1994) operated off the rear driveline but some used a front wheel as its input. This method was calculated by gear ratio, tire circumference and somewhat averaged how fast the vehicle was traveling. Later, when a vehicle had a different rear axle ratio installed or when different profile tires were used, the process of matching the plastic "speedo" gears was used to ensure accurate speed. This system of measuring speed did not have the capability of comparing individual wheel speed differences between two wheels like found between the inside and outside wheels during a turn. This technology is still with us today, but modern vehicles mostly rely on electronic sensors to perform that job.
The operation of most speed sensors (Soloman, S. 1998) is similar and might fall into one of three categories: variable reluctance, hall-effect and magneto resistive. As a result of the use of modern speed sensors, today's vehicles utilize this technology not only to monitor vehicle speed, but also to monitor component position or rate of speed change on virtually any moving part of the automobile. They can be mounted on the vehicle in a variety of locations to perform different tasks. The variable reluctance wheel speed sensor is basically a permanent magnet with wire wrapped around it. It is usually a simple circuit of only two wires where in most cases polarity is not important. The physics behind the operation include magnetic induction. A toothed ring on the wheel passes by the speed sensor and disrupts this magnetic field. The disruption in the field causes the wheel speed sensor to produce a sinusoidal voltage signal. The frequency and amplitude of the voltage signal are proportional to the speed of the wheel. The amplitude of the wheel speed signal is also directly related to the distance between the wheel speed sensor coil and the toothed ring.
Magnetic speed sensors (Silva, C. 1989) rely on a magnet as the sensing element to capture rotational or linear speed. They are typically used as gear tooth speed sensors or incorporated into stroboscopes or tachometers. The technology types for magnetic speed sensors include magneto resistive, inductive, variable reluctance and Hall Effect. In a magneto resistive sensor the resistance of the sensing element is a function of the direction and magnitude of an applied magnetic field. In an inductive sensor an oscillator circuit generates a radio frequency electromotive force that radiates from a ferrite core and coil assembly. The field is directed at the sensor face. When a metal target enters the field, eddy currents are induced into the surfaces of the target. This causes a reduction in the amplitude of the oscillator circuit and change in inductance. Variable reluctance speed sensors are typically self-generating and require no external power. When a magnetic surface is passed in close proximity to the sensor, a small voltage is induced. In a Hall Effect sensor, a current is passed through a semiconductor material. When a magnetic field is applied perpendicularly to the surface of the semiconductor, a voltage is developed. This Hall voltage is proportional to the applied field intensity, driving the magnetic speed sensor.
Analog variable reluctance speed sensor (Webb, J. and Greshock, K. 1993) is a passive sensor and requires no outside power source. The sensor generates a sinusoidal output voltage proportional to target speed and air gap. Analog signal is generated in response to fluctuation in magnetic field resulting from interruption by ferrous targets. This sensor can be configured for use in very high temperatures and high speed. The output voltage, depending on air gap and the target surface speed, ranges from a few milli-volts at the slowest target surface speed to several volts at the highest target speed.
The Delta speed sensor (GMH Engineering, 2003) is an inexpensive, non-contact Doppler radar speed sensor suitable for a wide variety of speed measurement applications. Small size and lightweight as well as requires only a small power source, making it useful in situations requiring portability or remote sensing. The sensor may be placed on a moving vehicle to measure vehicle ground speed. It also may be fixed in a stationary mounting to measure the speed of a moving object, which can be anything from a wire passing under the sensor to a vehicle a thousand feet away. The output of the sensor is a pulse with frequency proportional to measured speed. The cumulative number of pulses may be used to determine distance traveled or the length of a moving surface. Besides, it can be used with many different types of electronic hardware, such as timer, counters or digital tachometers, and can be integrated into electronic control or data acquisition systems.
2.2.2 Speedometer
Regular car speedometers can never know the exact speed of a vehicle without knowing how quickly the wheels rotate combined with the precise circumference of the tyres. Optical speedometer system (clausage, 2002) is installed on the underside of the car, seeing the surface of the road move beneath it and determines the speed of the car as well as the mileage. But using this system to calculate mileage might be easily foiled by a mounted sheet, to fool the system into thinking the road is not moving, thus stopping mileage increment.
Vehicle navigation using the Global Positioning System (GPS) has been of increasing interest over the past decade and GPS navigation is frequently installed in today's high-end luxury cars and in many commercial vehicles. Deductive reckoning (Analog Devices, Inc., 1995) is one method widely used in vehicle navigation. It utilizes three distinct inputs to predict position: a set of starting coordinates, the direction of travel, and the speed of travel. The ADXL202 dual-axis accelerometer can be used to develop accurate speed estimates for this navigation system. The method for determining velocity uses an accelerometer to sense the time interval for both front and back wheels to encounter a bump in the road while moving straight ahead. Whether one is driving on a local road or a highway, there will always be imperfections in the road. These imperfections translate into bumps and jolts sensed immediately by the car's wheels, and ultimately by its passengers. In order to track the speed by sensing these bumps, an accelerometer is used to identify their magnitudes and timing.
2.3 Components Implementation
2.3.1 Axiom CME11E9-EVBU Development Board
The functional architecture of today’s microcontrollers can vary from one design to another. However, all the designs consist of the same basic elements (Miller, G. H. 1999); there are a central processing unit, memory, including Read-only Memory (ROM) and Random Access Memory (RAM), Input/output circuitry and the address data and control buses. The Axiom CME11E9-EVBU development board, which is shown in Figure 2.1, has been chosen as a development platform for the Commercial Vehicle Speed Warning System. This board is a fully assembled and fully functional development system for the Motorola 68HC11 Microcontrollers. The main programming interface to this development board is the AxIDE program for 32-bit Windows. This program communicates with the development board via its COM port and includes a terminal window for interfacing with other programs running on the CME11E9 development board, such as the Buffalo Monitor or the Basic11 interpreter. It can also be used for displaying information or data from running programs that send output to the serial port. In addition to the terminal interface, this AxIDE program also provides an easy to use programming and configuration interface to the development board.
2.3.2 Serial Port (DB9S Style Connector)
The 9-pins D-type connector, commonly known as the DB9S connector (Texas Instruments Incorporated, 1995), is used as communication port between the host computer and the CME11E9-EVBU development board. Figure 2.2 show the pins diagram of the DB9S connector. Pin 1 is Data Carrier Detect (DCD), where the on condition of this signal line, as sent by the Data-Circuit-Terminating Equipment (DCE), informs the Data Terminal Equipment (DTE) that it is receiving a carrier signal from the remote DCE that meets its criteria. Pin 2 is Transmit Data line (TD), which refers to serial data from DTE to DCE, whereas pin 3 is Receive Data line (RD), which refers to serial data from DCE to DTE and when DCD is in the off condition, the RD signal must be in the MARK state. Pin 4 is Data Terminal Ready (DTR), where this signal in conjunction with Data Set Ready (DSR) indicates equipment readiness. Pin 5 is Ground (GND) terminal. Pin 6 is Data Set Ready (DSR) and is turned on by the DCE to indicate to the DTE that it is connected to the line. Pin 7 is Request to Send (RTS), where this signal indicates the DTE is ready to transmit data, and then the DCE must prepare to receive data. After some delays, the DCE turns on the Clear to Send (CTS) line to inform the DTE it is ready to receive data. Once communication is complete, the DTE turns off the RTS signal. After a brief delay to ensure that all transmitted data has been received, the DCE turns off CTS. Pin 8 is Clear to Send (CTS). This signal is turned on by the DCE to inform the DTE that it is ready to receive data. Finally pin 9 is Ring Indicator (RI) and is turned on by the DCE while ringing is being received.
2.3.3 Liquid Crystal Display (LCD) Port
A LCD display, which is connected to CME11E9-EVBU development board through the LCD display port is used to display time, date and speed information. The LCD display interface is connected to the data bus and memory mapped to locations $B5F0 through $B5F3. Addresses $B5F0 and $B5F1 are the command and data registers respectively. The LCD interface supports almost all LCD displays up to 80 characters and provides the most common pin out. Figure 2.3 shows the pins diagram of the LCD display port.
2.3.4 MC68HC11E9 Microcontroller
There are many of different architecture of microcontrollers available in market. The MC68HC11E9 microcontroller (Matloff, N. S. 1992) has been chosen as a microcontroller development platform instead of a Peripheral Interface Controller (PIC). Although the PIC may be easy to apply, it is limited in many ways that the MC68HC11E9 microcontroller is not. The MC68HC11E9 microcontroller as shown in Figure 2.4 has a versatile linear memory map and is expandable up to 64 kilobytes easily, but the PIC has only a fixed amount of internal memory and is not expandable. The MC68HC11E9 microcontroller provides a development environment onboard while the PIC must have an emulator system for similar development features. Besides that, the PIC has a small instruction set with little math capability and 8 bit operations only while the MC68HC11E9 microcontroller provides a large, easy to use instruction set with 16 bit math operations including multiply and divide instructions. In addition, the MC68HC11E9 microcontroller also provides 64 kilobytes indexing or pointers which are beyond the PIC capability. Additional board features include a solderless prototype area, Liquid Crystal Display (LCD) module port, keypad port and 32 kilobytes external static RAM for program debug or user data.
The MC68HC11E9 microcontroller is one of the MC68HC11 Family Members (Spasov, P. 1992). The microcontroller is a 52-pin Plastic Leaded Chip Carrier (PLCC) package and is an upgrade version of the MC68HC11A8. Figure 2.5 is a block diagram of the MC68HC11E9 microcontroller. This block diagram shows the major subsystems and how they relate to the pins of the microcontroller.
This microcontroller, which is manufactured by using the High-density Complementary Metal-oxide Semiconductor (HCMOS) technology, has 12 kilobytes of mask ROM, 512 bytes of RAM and 512 bytes of Electrically Erasable Programmable Read-only Memory (EEPROM). The main peripheral functions are provided on-chip, including the Analog-to-Digital (A/D) converter and an asynchronous Serial Communications Interface (SCI) as well as the main 16-bit free-running timer system. This timer system has three input-capture lines, five output-compare lines, and a real-time interrupt function. Besides that, a Computer Operating Properly (COP) watchdog system is included on-chip to protect against software failures as well as the powerful programmer’s model. The two 8-bit accumulators, accumulators A and accumulators B are general-purpose 8-bit accumulators used to hold operands and results of arithmetic calculations or data manipulations. In addition, these 8-bit accumulators can be used by some instructions as a single 16-bit accumulator called the D register, which allows a set of 16-bit operations even though the Central Processing Unit (CPU) is technically an 8-bit processor. Furthermore, two software-controlled power-saving modes; wait and stop mode, are available to conserve additional power. These modes make the MC68HC11 Family especially attractive for automotive and battery-driven applications, such as the Commercial Vehicle Speed Warning System.
2.3.5 FM Transmitter and Receiver Modules
The in-vehicle subsystem of the Commercial Vehicle Speed Warning System will be installed in commercial vehicle for speed monitoring, while the peripheral interface subsystem will interface with a host computer and act as a central controller for data setting and retrieving process. The communication between these subsystems is based on Radio Frequency (RF) transmission instead of infrared-based interface. This is because the infrared (IR) systems with an IR transmitter and IR receiver must be linked in line of sight (LOS) or directed method. This line of sight system has a directional transmitter and receiver that must be pointed at each other to establish a link. In addition, the line of sight path from the transmitter to the receiver must be clear of obstructions and most of the transmitted light should be directed toward the receiver. This directed link provides a limited angle of view and thus decreases the flexibility of link establishment. Moreover, these systems typically have difficulty in penetrating building walls and hence do not allow a user to communicate with the in-vehicle subsystem from office room. Besides, the infrared-based sensors can be affected by background light disturbance. However, these limitations can be solved by using the radio frequency-based sensors. Radio frequency transmission is not point to point but is multi-pathed and has the ability to travel through many opaque mediums allowing a RF signal to be detected even when it is not “visible” to the receiver. This means that the radio frequency-based sensors do not depend on availability of a direct vision contact between the RF transmitter and RF receiver. Due to these advantages, the Frequency Modulation (FM) transmitter and receiver modules (R. F. Solutions Ltd., 1999), which are shown in Figure 2.6, have been chosen to establish the wireless communication link between the subsystems.
This Ultra High Frequency (UHF) radio transmitter and receiver pair enables a data link at up to 40 kilobit/s at distances up to 75 meters in-building and 300 meters open ground, and the operating frequency is 433.92 MHz. This feature allows the user to communicate with the in-vehicle subsystem from the office room. Because of their small size and low power requirements, both modules are ideal for use in portable, battery-powered applications such as the Commercial Vehicle Speed Warning System. Figure 2.7 is a block diagram of the FM transmitter module, whereas the block diagram of the FM receiver module is given in Figure 2.8.
From Figure 2.7, pin 1 (RF GND) is connected to the RF return path or ground plane. Pin 2 (RF OUT) is RF output to the antenna and it is DC isolated internally. Whereas, Pin 3 (Vcc) is positive supply pin and the module will generate RF when the Vcc supply is present. Pin 4 (0 Volt) is connected to pin 1 and pin 5 (TXD) will accept either serial digital data (0Volt to Vcc levels) or high level linear signals.
From Figure 2.8, pin 1 (RF IN) is input from the antenna and it is DC isolate internally. Pin 2 (RF GND) is ground pin and is connected to the RF return path or ground plane. Whereas, pin 3 (CD) is carrier detect, which is used to drive an external PNP transistor to obtain a logic level carrier detect signal and will be connected to pin 5 (Vcc) if not required. Pin 4 (0 Volt) is suply ground connection and is connected to pin 1. Pin 5 (Vcc) is positive supply pin with 3.0 V to 6.0 V, whereas pin 6 (AF) is a buffered and filtered analogue output from the FM demodulator. It is useful as a test point or to drive linear decoders. Pin 7 (RXD) is digital output from the internal data slicer and is a squared version of the signal on pin 6 (AF). It can be used to drive external decoders and the data is true data as fed to the transmitter.
There are two modes of operation for data transfer between the in-vehicle subsystem and the peripheral interface subsystem, half and full duplex (Metzger, D. L. 1989). Since the in-vehicle subsystem is always in the communication slave mode and waiting for command from the peripheral interface subsystem, the half duplex mode is chosen for communication between these subsystems, where this mode of operation provides two ways conversation between components, but only one may transmit while the other receives and a pause in data flow must be achieved to switch directions of the data flow. In this case, the both subsystems must use the same communication protocol.
2.3.6 Analog Switch (4066)
Since the half duplex mode is chosen for communication between the in-vehicle subsystem and the peripheral interface subsystem, the analog switch (Maxim Integrated Products, 2000) is used to switch on or off the FM transmitter and FM receiver. The analog switch as shown in Figure 2.9 is connected between the power supply source and the positive power supply pin of the transmitter or receiver in conjunction with control line from the central microcontroller. The switch is closed if the appropriate control line is HIGH, which allows the power supply to pass to the transmitter or receiver, otherwise it's open. This switch is digitally controlled analog switch utilizing advanced silicon-gate Complementary Metal-oxide Semiconductor (CMOS) technology and it is a bidirectional switch, thus any analog input may be used as an output and visa-versa. Besides that, the analog switch allows control of up to 12V analog signal with digital control signal of the same range. The microcontroller will enable the control line before a serial data is sent to the transmitter or received from the receiver. Hence, the both subsystems must use the same communication protocol in the wireless communication link.
2.3.7 Hall Effect Gear Tooth Sensor
The Hall Effect Gear Tooth Sensor (Honeywell International Inc., 2001) as shown in Figure 2.10 is used as a speed sensor to measure the vehicle speed through vehicle engine. This Gear Tooth Sensor uses a magnetically biased Hall Effect integrated circuit to accurately sense movement of ferrous metal targets and this specially designed Integrated Circuit (IC), with discrete capacitor and bias magnet, is sealed in a probe type package for physical protection. In this sensor, the Hall voltage is generated by the effect of an external magnetic field acting perpendicularly to the direction of the current flow. Hence, the sensor will be placed in close proximity to a toothed ferromagnetic disk and the sensor will produce a digital square wave signal, which is directly proportional to the velocity of the vehicle and this square wave signal is generated whenever the target wheel teeth edges pass the sensor surface.
In addition, the optimum sensor performance is dependent on some variables, including the toothed wheel material, toothed wheel rotation speed, gap between sensor and toothed wheel as well as environment temperature. Moreover, this Gear Tooth Sensor will function from a 4.5 to 24 VDC power supply and one of the major advantages of this sensor is reverse polarity protection.
2.4 Out-vehicle Speed Tracking System
2.4.1 AutoPatrol PR-100: Speed Camera System
The PR-100 (TransCore IP, Ltd., 1991) is among the most advanced speed camera systems available. It couples sophisticated radar technology and digital signal processing with the latest in high speed photo imaging. The unit is a compact, portable, camera-radar device that easily mounts on a tripod or on a permanent fixture. Besides that, the PR-100 features an integrated digital video system that can monitor and record traffic as it passes through the enforcement zone. Only vehicles exceeding the preset threshold or speed limit are photographed, which enable driver identification. Moreover, the digital signal processing ensures precise speed measurement, vehicle classification, target discrimination and photo positioning as well as provides sharp, clear day and night photos across multiple lanes. In addition, optional twin-camera configuration in this speed camera system will enable photo capturing on front and rear images of the speeding vehicles.
2.4.2 SPECS System: Cameras and Detection Systems
The SPECS system (Acquidyre Ltd., 2000) utilizes state of the art video system with Automatic Number Plate Reading (ANPR) digital technology. It consists of a minimum of two cameras each fitted with infrared illuminators fitted on gantries above the road. These cameras work out the vehicles average speed and this speed is determined by measuring the time the vehicle takes to drive between the two camera positions. Besides that, the SPECS system can be also fitted either at the roadside or central reservation a set distance apart to create a speed controlled zone, or where appropriate, groups of cameras can be linked to create a speed controlled network. As vehicles pass between the entry and exit camera points, their number plates are digitally recorded, whether speeding or not. Then, by ANPR recognition, the images on the video of matching number plates are paired up, and because each image carries a date and time stamp, the computer can then work out the vehicle average speed between the cameras and will make a decision if the preset speed threshold is triggered. This data is then digitally stored on a central computer, so that there is no need for film to be collected and changed at the cameras site.
2.4.3 Speedmaster DS2
The Speedmaster DS2 (Radarfalle, 1999) is developed for police forces needing a device that will detect speeding vehicles automatically and with certainty on quiet and busy roads. This device uses discrete surface sensors for temporary sites and sub-surface piezo sensors for permanent sites. Besides that, an extension reel is run out the required distance to a position where the operator can view the traffic crossing the sensors and stop offenders as required. Moreover, the Speedmaster DS2 only displays over speed vehicles, thus simplifying the operating process. In addition, the system can be used manually, with operator stopping and charging offending drivers, or connected to the AUTOVISION 2, which records the offending vehicles on video for later processing and issuing of tickets or summonses from a central ticket office.
2.4.4 Speedster Radar Gun
The Speedster radar gun (Trading Direct Ltd., 1997) is the complete opposite to a radar detector. It uses digital technology and digital signal processing to provide instantaneous real time speed measurements to +/- one mile per hour accuracy and can be used to measure a vehicle speed when traveling between 6 to 200 miles per hour. With the trigger engaged, operator can see the real time speed measurement of the vehicle as it accelerates or decelerates. Furthermore, the Speedster can also keep track of statistics such as current, last and average speeds of the speeding vehicles and the operator can also choose between measuring in miles per hour or kilometers per hour.
2.4.5 SpeedLaser: Speed Measurement System
The SpeedLaser (Laser Atlanta, LLC., 2003) provides law enforcement a highly accurate solution to measure the traveling speed of vehicles. It is laser-based as opposed to radar, which provides several advantages including the ability to target a single vehicle on busy roadways and fast measurement speeds. With a target size of only 75mm at 100 feet and the ability to take a reading of a targeted vehicle in just 0.3 seconds, speeding motorists have very little chance of detecting the SpeedLaser or slowing down before a reading is taken. Besides that, police are able to perform traffic stops more safely because of the SpeedLaser’s test-proven ability to accurately record the speed of an approaching or receding vehicle at 3/8 mile away. The officer has the time to safely enter traffic and pull over a speeding motorist. In addition, the inclement weather features of the SpeedLaser improve law enforcement’s ability to target and measure offending motorists.
2.4.6 COMBI: Speed and Traffic Data Processing System
The COMBI (SPG Media Ltd., 2004) is the only system to offer three traffic management options in one compact instrument, as it is an automatic speed and traffic light violation recording system equipped with a 35mm camera, with the capacity to capture and process data. In this system, primary speed measurements are made using three or four thin piezo sensors, either sub-surface (installed at permanent or semi-permanent sites) or surface-mounted (used at temporary sites for random speed checks). Besides that, the COMBI system provides three photographic software options. The first option takes a picture of the front of the vehicle, providing an image of the front number plate and the driver. A second software option, suitable for front or rear vehicle photography, takes two photographs of the vehicle, 20m apart. The third option takes two photographs of only the rear of the vehicle, separated by half-a-second. Moreover, a paper printer, when attached to the remote control unit, will print detailed information about each violation as well as statistical information required for monitoring the success of law enforcement program. In addition, for permanently installed sites, stainless steel housing is supplied as standard, fitted with bullet proof plates and glass to protect the instrument against hand guns and vandalism.
2.5 In-vehicle Speed Monitoring System
2.5.1 Speed Trak II: Vehicle Speed Monitoring System
The Speed Trak II (Matco Industries Inc., 2004) is a speed monitoring device that is installed in each vehicle to track and report information pertaining to speed, location, and direction. The Matco Industries Inc. is a primary supplier to the Malaysian government for their vehicle speed monitoring initiative, which is used as an aid to highway law enforcement. The vehicle speed monitoring system development program is being conducted under the request of the Ministry of Transportation in the nation of Malaysia. The government had legislated the enactment Motor Vehicle (Construction, Equipment and Use Speed Warning Device) Rules 1985, for a system to be introduced into commercial vehicles to monitor speed violations. However, the system proved to be ineffective because the equipment was not tamper resistant.
2.5.2 Track Star Fleet Management System
The Track Star Fleet Management System (Track Star International, Inc., 2000) is a GPS based Automatic Vehicle Location (AVL) system used as a tool for fleet management applications. The system uses the GPS together with advanced telecommunications technology to provide a powerful security, location and communication tool used to measure and adjust the operational efficiency of vehicle fleets. The Track Star Fleet Management System is comprised of two primary components, the Track Star Fleet Manager Software, which will be installed in a host computer, and the Track Star Vehicle Location Units (VLU) installed in fleet vehicles and is used to monitor the vehicle parameters. The software works in close coordination with the VLUs to provide an extraordinarily powerful fleet management and communication tool. The VLUs embody a GPS receiver, proprietary electronics and a cellular transceiver to allow the user or operator the ability to locate, track and communicate with vehicles on the road. In addition, the Track Star Fleet Management System provides managers with a completely autonomous system to locate and manage their fleet. All relevant information such as location, speed, mileage and direction is collected and stored in the Track Star VLU and this information can be retrieved by using the wireless communication links. When information on location is needed, the managers can simply go to their desktop or laptop computer with the Track Star Fleet Management Software and identify the vehicle, and view the information they require.
2.5.3 Transportation Technology Solutions
The Mobius Transportation Technology Solutions (TTS) system (Cadec Corporation, 2004) is developed for fleets in the commercial trucking industry. At the heart of the Mobius TTS system is the Onboard Computer (OBC), which will be installed in the vehicle. This powerful computer is ready to track the vehicle performance, driver productivity, safety and compliance information as well as a variety of other business information needs. The Mobius TTS is modular and expandable. The users can customize his solutions by choosing only the tools needed to meet their business objectives. One of the features that will monitor the vehicle operation is the basic vehicle information monitoring system. This system provides accurate vehicle data capture information such as accidents, engine idle time, miles traveled, speed warnings and violations, and automatically generated sudden decelerations. Besides that, an audible and visual warning from the onboard computer also helps the drivers informed and alert so they can maintain safe vehicle handling practices.
2.5.4 DriveRight 600 Vehicle Driver Safety Monitor
The DriveRight 600 (Davis Instruments Corporation, 2003) is used to monitor and log vehicle trip information including detailed driver performance data. All data recorded by the DriveRight 600 can be downloaded to a computer by using the DriveRight Fleet Management Software (FMS). The interactive Liquid Crystal Display (LCD) on the system allows user to set the speed, acceleration and deceleration limits and to view the trip data. Moreover, an internal audible alarm is also used to alert the drivers whenever one of the preset limits has been exceeded. In the event of an accident or sudden stop, the DriveRight 600 also records the vehicle speed for each the 20 seconds before and after a sudden deceleration. In addition, the system also monitors the vehicle functions such as brake lights, headlights and seatbelt. The DriveRight GPS Module provides detailed information of a vehicle’s route by recording the latitude and longitude at time intervals determined by the manager.
2.5.5 Fleet Manager 100
The Fleet Manager 100 (Siemens VDO Automotive, 2004) is the smaller of the Fleet Manager On-Board Computers for recording driver and vehicle data. It is easy to install and reliably and precisely store all relevant data for the vehicle up to 709 trips. If desired, the starter interruption, present as a standard feature, can be connected to force drivers to log on. With a minimum of effort the data can be transferred with data plug to the computer, where it can be evaluated by all Fleet Manager Software Packages. The Fleet Manager 100 can be installed in all earth-bound vehicles except motorcycles and it is suitable for vehicles with 12 or 24 Volt electrical systems. As a standard feature, the on-board computer will record the maximum vehicle and engine speed during each trip as well as the distance driven per trip. Moreover, the standing and parking times together with the beginning and end of trips with date and time for the vehicle will also be recorded by the system. In addition, the driver can be given warning signals (buzzer and light emitter diode display) for over speeding violations, memory full and malfunction.
2.5.6 Wireless In-vehicle Fleet Monitoring System
The Wireless In-vehicle Fleet Monitoring System (Vetronix Corporation, 2004) is installed in vehicle and enables fleet management system users to receive data directly from the individual vehicle via wireless links. Unlike other in-vehicle systems that offer only GPS data, the system also retrieves information directly from the vehicle's on-board computers. In addition to GPS, the system also retrieves and transmits data such as vehicle speed, engine speed, odometer value, fuel levels, engine RPM, diagnostic trouble codes, door lock/unlock controls and airbag deployment. Besides that, it can be installed in the police cruiser, and will be connected to both the engine control module and other outputs, such as the emergency light bar, headlights and door lock/unlock systems.
2.5.7 V-Count II: Vehicle Speed Monitoring System
The V-Count II (Apexvalue Corporation, 2002) is used to monitor vehicle speed and to determine if the vehicle has exceeded the preset speed limit. The speed signal supplied to the V-Count II is processed by a microprocessor that compares it with a stored calibration value to determine the vehicle speed at any instant of time. When the maximum speed limit set by the vehicle owner or fleet manager is violated, a loud warning tone is sounded. This warning tone remains on until the vehicle speed is reduced below the maximum speed set point. The time in seconds of an over speed violation before a violation is logged can be set in the range of 1 to 20 seconds. However, the default setting is 5 seconds. A flashing red light will turn on if the speed violation lasts for longer than the set time. This over speed indicator light can only be switched off by an authorized person entering the six digit security code. Each violation that exceeds the over speed violation set-point will cause a speed violation counter to increment up to the maximum count of 99 for each instance of violation. Besides that, if the V-Count II is disconnected for more than 20 seconds and then reconnected, a red flashing tamper light will start flashing.
2.5.8 The SafeForce Driving System
The SafeForce Driving System (Road Safety International, Inc., 1999) is used to monitor and record unsafe vehicle operating parameters such as speeding and high vehicle G-forces caused by rapid accelerations, hard decelerations and high speed turns. The system provides an audible warning as the driver approaches an unsafe condition, allowing sufficient time to take corrective action before a crash occurs. If a driver ignores system warnings, an exception report is created so management may take corrective action. Besides that, the system also creates a database reports ranking driver performance. These reports encourage competition between groups of drivers to drive safely, without excessive vehicle forces. This interactive SafeForce training approach is a best way to prevent crashes and drastically reduce fleet maintenance costs. Moreover, the system doesn't just document why a crash occurred, it helps prevent the crash from happening in the first place. The immediate audible feedback will warn the drivers of excessive forces (due to hard cornering, for example) and over speeds. At this point, the drivers have the opportunity and incentive to correct their mistake before it results in a crash.
2.6 Conclusion
Almost all the world's police forces use radar or laser speed gun for measuring speed, enforcing speed limits and collecting revenue. However, ever since it was invented, anti radar and laser measures such as radar or laser detector and jammer have followed close behind, which allow speeder to stay one step ahead of the traffic officer. When the radar or laser jammer detects a radar or laser gun signals, it will visually and audibly notify speeder of police radar or laser gun attempting to read the vehicle speed. The jammer also scrambles the radar or laser signals from the police radar or laser gun returning a blocked signal, making it virtually impossible for police to read the vehicle speed. For a few seconds, the laser gun’s display will not produce any speed reading, leaving enough time for the driver to check, and if necessary, adjust vehicle speed safely.
Since the traffic officers are trained to aim the laser guns at vehicle front license plates as the plates provide an excellent retro-reflective surface, the speeder can also get special plastic covers that reduce the reflectivity of the license plates. This measure reduces the effective range of the speed gun system, but not the range of the driver's laser detector and jammer. With this extra time, a speeder might be able to slow down before the speed gun can get a read on the vehicle speed.
Besides that, laser beam or radar signal from the speed gun can be affected by atmospheric conditions, especially on humid, foggy or rainy days, which can significantly reduce the operating range of the speed gun. Moreover, when the laser beam bounces off more than one solid object (stationary or moving), reflection errors occur, producing an incorrect speed reading on the speed gun. Furthermore, refraction errors can produce incorrect speed readings, where light is refracted differently by hot air than cooler air, a spot of air rising from the roadway can confuse the laser gun.
Apart from that, police enforcement cameras on the side of road, usually placed to catch transgressors of the stipulated speed limit for that location. These speed cameras are there solely to identify and prosecute those drivers that pass by them when exceeding the stipulated speed limit. At first glance this seems to be reasonable. But, if these cameras are highly visible then no drivers would travel by them exceeding the speed limit and may slow down just in that location and then increase their speed further down the road. Used as they are, hidden away, they penalize only and contribute little to road safety directly as well as only generating revenue to pay for their installation and maintenance. So, hidden speed cameras do not help maintain or enforce road safety standards, only penalize transgressors, whereas, with highly visible speed cameras will make the drivers slow down and obey the speed limit just in that enforcement zone.
If these speed cameras are the only way to make drivers slow down, and they work effectively, then there should be a great number of these cameras everywhere and that they would be highly visible and identifiable to make drivers slow down, but that is not the case. The speed cameras are invariably hidden behind trees, road signs and are a dull grey colour. The way the speed cameras are currently used is not to make the drivers slow down, obey the speed limit and make the road safe but to catch and penalize transgressors who may otherwise have slowed down if they have seen the camera in advance.
Due to these reasons, the long term “Road Safety” value of these out-vehicle speed tracking devices is unclear and the in-vehicle speed monitoring system will be considered, which can provide continuous speed tracking and monitoring features. Knowing the presence of such monitoring system in the vehicle, logging the driver speeding activities will discourage the driver from speeding and accumulating too many numbers of speeding violations and hence, this will drastically reduce the probability of road accident.
The Speed Trak II is an in-vehicle speed monitoring device that is currently used in commercial vehicle in Malaysia. This system is introduced due to large amount of the commercial vehicles operating in country and the traffic officer can't be everywhere to enforce the speed limits. However, the system proved to be ineffective because the equipment is not tamper resistant. It is common amongst the vehicle owner or operators to defeat the speed monitoring system by instigating a fault to the equipment or disconnecting the power source of the system to disable the proper operation of the system. Moreover, this system utilizes wireless infrared interface for data setting and retrieving process, where the transmitter and receiver must be linked in line of sight method to establish a communication link, which provides a limited angle of view and thus decreases the flexibility of link establishment. Aiming at the best solution for in-vehicle speed monitoring system, it is expected to incorporate an anti-tampering function in the system to curtail all attempts of tampering on the system and wireless radio frequency interface will be designed instead of using the wireless infrared interface for data setting and retrieving process.
Besides that, fleet management systems are examined and analyzed, with their function appears to be similar to the concept of the in-vehicle speed monitoring system. But, these products are performance enhancement tools and the information gathered from these fleet management systems are business or profit related tools and allow the fleet manager to track the productivity and the efficiency of his drivers as well as provide little vehicle speed information. The market research shows that this fleet equipment is not applicable to road safety as well as the cost of the product is too expensive, and it is decided to develop the Commercial Vehicle Speed Warning System from the ground up, utilizing existing technology and programming knowledge.
[...]
-
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen. -
Laden Sie Ihre eigenen Arbeiten hoch! Geld verdienen und iPhone X gewinnen.