GB2343252A - Vehicle speed monitoring - Google Patents

Abstract

A system of monitoring the speed of a vehicle comprises three subsystems. The first is a speed measuring device attached to the vehicle which stores speed data, especially traffic law violations, and can also alert the driver to instances of speed violation. The second is a transportable hand held device (<B>26</B>) for receiving and storing information recorded by the first subsystem, for use by law enforcement personnel, and includes several security features to prevent unauthorised use and tampering. Data is transferred to the second device via an infra-red communications module, At the end of the data transferral to the hand held device, the data can be transmitted to a third subsystem receives and stores information provided by the transportable device.

Description

VEHICLE SPEED MONITORING SYSTEM Field of the Invention The present invention relates to the field of vehicle speed monitoring. In particular, the present invention provides a system for continuously monitoring vehicle speed, and detecting violations of legal speed limits. The present invention also provides means for law enforcement personnel to access data from vehicles.

Currently, traffic law enforcement in most jurisdictions is a daunting task. There are simply too many vehicles on the road for a reasonably sized police force to monitor by direct observation. In the absence of strict monitoring of vehicular speed, there is a tendency for drivers to exceed legal speed limits. This is especially true for drivers of commercial vehicles, since the financial return in respect of a commercial vehicle such as a truck or bus will be directly dependent on the speed with which a driver can use it to perform tasks.

Vehicle speed monitoring by police forces has heretofore been accomplished by direct observation of vehicles. This can be accomplished by radar scanning of the vehicle in motion, by timing the vehicle from point to point, or by tracking the vehicle in a second vehicle of known speed. There are also systems in some jurisdictions to alert police to fast moving vehicles. For instance, it is known to mount warning lamps on trucks, to light up when the vehicle is speeding. However, this only assists in the direct observation method of enforcement of speeding laws, since a law enforcement officer must actually observe the warning lamp, and then measure the speed of the vehicle.

The object of the present invention is to provide a complete closed loop system. This includes the in-vehicle speed monitoring system accompanied by two distinctive peripheral support subsystems. The sub-systems are for use by law enforcement personnel and appointed government depots. The law enforcement system allows only for the review of data stored to the in-vehicle system and that the issuing of tickets to the owner of the vehicle is at the discretion of the officer.

In the case of a depot, the altering, adjusting and erasure of stored data and events from the non-volatile memory system of the in-vehicle speed-monitoring system is possible.

The system of the present invention also includes appropriate electronic and mechanical sensing and support devices, as will be discussed in detail below.

In a broad aspect, then, the present invention relates to an apparatus for monitoring vehicle speed, and detecting episodes of vehicle speed in excess of a predetermined maximum speed, including: a first subsystem for mounting on a vehicle to monitor and record vehicle speed related information; a transportable device for receiving and storing information recorded by said first subsystem; and a second subsystem for receiving information stored by said transportable device.

Brief Description of the Drawings In drawings which illustrate the present invention by way of example: Figure 1 is a perspective view of typical speed sensors for use in the in-vehicle subsystem of the present invention; Figure 2 is a perspective view of a typical RPM sensor, for use in the in-vehicle subsystem of the present invention; Figures 3 and 3A are exploded and perspective views of a warning driver alert centre for use in the in-vehicle subsystem of the present invention; Figure 4 is an electrical wire harness block diagram for an in-vehicle subsystem of the present invention; Figure 5 is a perspective view of a main control module for use in an in-vehicle subsystem of the present invention; Figure 6 is a perspective view of a portable data reader for use in the present invention ; Figure 7 is an exploded view of the said portable data reader; Figure 8 is a schematic of a data reader liquid crystal display graphics and text in a preferred embodiment of the present invention; Figures 9 and 9A are perspective views of a data reader peripheral docking bay for use in the present invention; Figure 10 is a perspective view of a data reader/eraser calibration module and a host computer, for use in the present invention; Figure 11 is an illustration of the means of calibration of the in-vehicle subsystem of the present invention; Figure 12 is a perspective view of a calibrator interface for use in the present invention, Figure 12A being an exploded view thereof; Figure 13 is a block diagram of the vehicle speed monitoring control module; Figure 14 is a block diagram of the DACM with optional forward facing optional beacon lamp and liquid crystal display; Figure 15 is a block diagram of the Data Reader; Figure 16 is a block diagram of the DRBD Unit, controller; Figure 17 is a block diagram of the DREC unit; Figure 18 is a block diagram of the CI unit.

Detailed Description The vehicle speed monitoring system (VSM) of the present invention consists of three subsystems, the in-vehicle subsystem and the two peripheral support sub-systems.

The in-vehicle subsystem consists of a main control module and multiple sensors and interface/output devices, all interconnected by a prefabricated wire harness. The in-vehicle system is preferably installed and individually calibrated into every commercial duty and/or official heavy vehicle.

The peripheral sub-systems, divided into the support subsystem and the enforcement subsystem, allows the proper calibration and certification and re-certification of the in-vehicle systems, as well as data downloading, and audits of the same.

This also includes devices that support the collation of the distributed data to a central database within a particular jurisdiction or state.

In-vehicle Subsystem The in-vehicle system of the present invention may be broken down into several parts, the central control module, the sensors, the output devices, wire harnesses, and various hardware components.

The Speed Sensor (Figure 1) The speed sensor detects the rotation of the drive shaft and converts these signals into electrical pulses. There is a wire and connector from either of the variations that is connected to the main harness.

The RPM Sensor (Figure 2) The RPM sensor detects the revolutions of the engine and converts the RPM signal to electrical pulses. There is a wire and connector from this unit that is connected to the main harness.

The Driver Alert Centre Module, (DACM), (Figures 3 and 3A) The driver alert centre (Figure 3) is the visual and audio output device of the in-vehicle system. Mounted on the vertical surface of the instrument panel, it allows for easy indication and viewing by the driver. The outward forward facing optional beacon lamp (Figure 3a) is mounted onto the upper portion of the windscreen or can be mounted onto the exterior roof of the cab portion of the vehicle. The DACM, will by means of the visual and audio circuits, indicate to the driver/operator his current speed violation status by a variety of flashing patterns and audible tones, in the event that he is speeding. The DACM has the option of having a Liquid Crystal Display (LCD) for the purpose of written text messages from the in-vehicle system, i. e. display the current total of accumulated violations.

The Main Harness (Figure 4) The main harness and its various extensions connect electrically the main Control Module (CM) to both sensors and output devices; the CM provides the needed power to all of the VSM in-vehicle peripherals.

The Control Module, (CM), (Figure 5) The CM receives pulses from the various sensors and signals through connectivity of the wire harness. Embedded proprietary software analyses these pulses and signals and compares all of these continuously updated signals to set internally memorised values. From these comparisons, over-speeding or tampering is determined, depending on what the particular vehicle is engaged in at that time. If the state is over-speed, then the conditions, i. e., date, time, speed, details etc. are written to integral memory and an alarm triggered through the means of the connected DACM. If the vehicle is stationary and tampering is detected then the conditions, i. e., date, time, tamper code type, etc. is written to the integral memory.

The Ignition Relay The ignition relay is in place to open the starter circuit of the vehicle. The relay as mentioned is an integrated into the CM printed circuit board assembly. When, a pre-set number of violations are attained, the relay is opened, rendering the starter circuit inoperative, in a preferred embodiment.

Various Hardware components The in-vehicle systems are installed with various hardware components, screws, bolts, etc. Key components, such as the speed sensor, CM unit, and specific connector junctions of the wire harness, preferably have additional numbered security tags wired around the installed units to discourage unauthorised removal or tampering. Each tag is branded with a unique serial number and the application crimping tool imprints the installer's assigned identification number. Thus the security devices can be tracked and traced to the location and day of installation, along with the installer.

Peripheral Support Svstems (Figures 6 and 9) The peripheral support systems of the present invention may be broken down into several parts, being the Data Reader Eraser/Calibrator module and related devices for the support subsystem and the Data Readers and related devices for the enforcement subsystem. Integral into each of these systems is custom copyright software embedded into each of the microprocessors of each assembly, or running in a separate computer, either laptop or desktop personal computer configuration.

THE SUPPORT SUBSYSTEM The Data Reader Eraser/Calibrator Units (Figure 10) The in-vehicle system once installed must be initialised, calibrated and certified. The instrument used for this purpose is called the Data Reader Eraser/Calibration module, (DREC).

When connected to a laptop computer, the DREC provides an infrared communications link to the in-vehicle system through the DACM and. It allows a technician access to the data stored within the CM unit as well as the ability to alter and set the operating parameters of the system. The technician can also set the system to its pre-calibration state and thus prepare the vehicle for calibration.

Calibration Systems The in-vehicle system is calibrated to the true road speed of the vehicle with the use of a calibration system. These systems can be either a stationary dynamometer system or a portable calibration system, both means require the interconnection of the calibrator interface unit.

Calibration Sensor (Figure 11) The calibration systems (Figure 11) depict two types of calibration systems. The stationary system is based on a running wheel dynamometer and the second system is based on a type of non-contact microwave sensor that senses the distance travelled by the vehicle over the ground. Both systems output a set number of pulses per unit distance travelled. Thus, the faster the vehicle travels the greater number of pulses are outputted per sampled period. The pulse data output signal is connected to the calibration interface unit and is processed accordingly. Other types of dynamic and static calibration will be obvious to those skilled in the art.

The Calibration Interface Unit-Calibrator (Figures 12 and 12A) The calibrator interfaces the in-vehicle system to the calibration system. It is connected to the Calibration Sensor through a computer cable and to the VSM CM via a signal wire through the wire harness assembly. The unit is powered from the vehicle's own power system, (vehicle battery), then provides power to other systems requiring vehicle power. The pulse signal received from the Calibration Sensor system, either being stationary or portable is compared to pre-set programmed values. The calibration interface unit by means of embedded copyright software and dip-switch settings determines when the vehicle has achieved the calibration set velocity. When the vehicle has achieved the set calibration velocity, the calibration interface unit outputs a signal to the control module. The control module then stores the data from the various signals, being received from its own various sensors and signals, into the internal non-volatile memory.

Visual and audio alarms in the calibrator indicate to the calibration technician the status of the calibrator and VSM.

The calibrator is equipped with a talk-through adapter that allows monitoring of the calibration activity through a laptop computer.

THE ENFORCEMENT SUBSYSTEM The Data Readers (Figures 6,7 and 8) The hand-held Data Reader (DR) units give users the ability to review and retrieve data stored in the in-vehicle control modules'memory via the wireless infrared communications link.

These DR units are assigned to law enforcement officers under normal circumstances. With the data in readable form, the officer can access the data and issue tickets if warranted.

The DR unit has limited capabilities beyond reviewing and retrieving data and the issuance of tickets. The tertiary function of the DR is the ability to reset the violation counter if the officer issues tickets against stored violations and/or infractions and thus enable a VSM shutdown vehicle to be restarted should the vehicle have reached this state of operation. The DR cannot erase the memory, nor can it alter the set performance parameters of the VSM.

The Data Reader Docking Bay (Figures 9 and 9A) The Data Reader Docking Bay (DRDB) system allows the retrieving of stored data from handheld Data Readers. Multiple DR units may be plugged into the DRDB simultaneously.

Installed enforcement station locations, a DRDB is connected to a personal desktop computer running proprietary copyrighted application software. Officers coming off their duty shifts plug their DR units into the DRDB. All functions after the placement of the DR to the DRDB is transparent and automatic.

The data from each DR unit is saved as readable file to a database file within the desktop computer. Initiating the battery charge cycle for each DR follows this. In a practical embodiment, the DRDB can accommodate up to 128-DR units simultaneously.

THE IN-VEULE SYSTEM The Speed Sensor, (Active Sensor), (See Figure l ! The speed sensor (1) is a transducer that is installed between the transmission drive pinion gear and the speedometer cable of the vehicle. The connected transducer has a built in rotary encoder that outputs a set number of pulses per revolution and allows for direct passthrough mechanical connection of the speedometer cable. Since the revolution of the drive pinion shaft is directly coupled to the drive shaft of the vehicle, the output of the sensor is directly proportional to the ground speed of the vehicle. The sensor does not have any ratio adapters built in, it is straight through, and thus the speedometer performance remains unchanged. The sensor has wires that are terminated to connector. Connector (C18) of the sensor couples to connector (Cl7) of the speed sensor extension harness (see Figure 4). The connector (C18) is a four pin shrouded sealed connector.

The connector locks into its corresponding mating connector on the speed sensor extension harness and forms a water, grease and dust proof connection.

The speed sensor (1) is installed at the pinion drive gear of the transmission of the vehicle. Various adapter drive tips such as the one shown allow the sensor to be driven by a variety of different transmission drive configurations. These drive tip adapters are purchased separately from the various manufacturers.

A select number of vehicle configurations do not allow the installation of the speed sensor directly to the transmission speedometer drive output. This may be because the drive configuration is too specialised and generic adapters are not available, or the speedometer method of attachment is not the same as standard heavy vehicle convention. There may also not be enough physical room to install the sensor its supplied configuration. These cases require special procedures and adapter hardware in order to install a speed sensor to the vehicle.

The sensor (1) is mounted and a security tag is placed around points of the sensor, which makes removal the sensor apparent.

A speed sensor suitable for use in the present invention is available from Arthur Allen Manufacturing U. S. A.

Speed Sensor Extension Harness The speed sensor extension harness (4), (see Figure 4) electrically connects the speed sensor to the central harness.

It is a fabricated four-conductor harness, 18AWG stranded tinned copper wire, cut to a specified length. The wire is rated for harsh environment and has a temperature rating of -20C to +105C.

Usually the speed sensor is located near the back of the transmission; the harness extension must reach from the under dash location of the CM unit back down the undercarriage of the vehicle to the rear transmission area.

Both ends are terminated with a four position sealed mating connector (C16) and (C17), and the entire length of wire is jacketed in a split plastic sleeve for protection. Connector (C16) is coupled to connector (C15) of the central harness, as illustrated in Figure 4.

The RPM Sensor (see FiQUre 2) The sensor (3) is a magnetic proximity detector installed into the transmission bell housing of a vehicle. The sensor is a type of device that when a ferrous mass passes in front of the sensing face, generates a small electrical potential. In this application, the individual gear tooth of the starter gear acts as the ferrous mass. The output is a sinusoidal signal, the frequency equal to the rate the individual gear teeth that pass in front of the sensor face.

The output signal is connected to the CM unit through a RPM Sensor Extension harness. The connector (Cl4) is a sealed, shrouded, locking male connector that locks into the corresponding female connector on the RPM extension harness.

Connector (C14) couples to connector (C13) on the RPM extension harness (see Figure 4). An appropriate RPM sensor for use in the system of the present invention is obtainable from Wabash Electronics U. S. A.

RPM Sensor Extension Harness The RPM sensor extension harness (6) electrically connects the, RPM sensor to the central harness. It is a fabricated two-conductor wire harness, 18AWG stranded tinned copper wire, cut to a specified length. The wire is rated for harsh environment and with a temperature rating of-20 C to +105 C.

Usually the RPM sensor is located midway between the transmission and engine adjacent to the starter ring gear in the bell housing. The harness extension must reach from the under-dash location of the CM unit, back down the undercarriage of the vehicle to the location as specified.

Both ends are terminated with a two position sealed mating connector (C12) and (C13), and the entire length of wire is jacketed in a split plastic sleeve for protection. Connector (C12) is coupled to connector (Cll) of the central harness, as illustrated in Figure 4.

The Driver Alert Centre, (DACM), (see Figures 3 and 3A1 The driver alert centre 15 of Figure 3 contains the audio alert 153, a visual indicator 151 (LED) and the infrared communications module 152. The assembly consists of an integrated plastic housing into which is installed an electronic printed circuit board and the two lenses. The assembly has been designed to allow for placement into tight and restricting areas. However, the front surface or face of the unit is to be placed in clear view of the driver allowing visual notification of the system status in addition to visual indication of speeding or the approach of the speed limit. The secondary requirement to have the face of the unit in clear view is to allow for infrared communication with the support systems.

The audible alarm transducer 153 is an integrated part of the upper housing assembly, which allows for unhindered sound dispersion when active.

The main circuit PCB 154 contains the infrared communications components, control circuitry, power regulator and protection circuit. A six conductor locking header connector (C3), (Figure 4) is soldered to the board and when coupled with (C4a) of the driver alert centre extension harness (18), allows electrical connection to the rest of the VSM in-vehicle system. The DACM includes on the PCB a 2-pin connector that allows for the connection of an optional visual warning lamp as described.

The optional visible warning beacon lamp (Figure 3a) 155, is made of twelve high power pre-focused amber Light'Emitting Diodes 156 (LED's) positioned on the PCB 157 in a circular pattern array. The twelve LED's are soldered directly to the PCB. The combined luminance power of the array is such that when projected through the lens, it is highly visible when viewed on-axis in noon sunlight. The intensity however is not high enough to make the driver alert centre light blinding or highly distracting when viewed at night or in a dark environment.

The optional visible warning lamp has a 2-pin connector port located to the base of the unit and allows for connection of a custom wire harness assembly. The mounting of the unit can be either to the interior of the cab or be placed to the exterior cab roof. Appropriate mounting hardware is provided. The extension leads from the DACM pass under the instrument panel and up the"A"pillar, and across to the two-pin connection port of the visual warning lamp. Both ends of the wire harness assembly are fitted with moulded over strain relief bushings.

Optional to the DACM is the liquid crystal display, (Figure 3). The LCD, when installed, allows for written text messages from the control module to be displayed. The display can be set to allow for the continuous display of the current number of violations stored to the control module, or any other pertinent information of the system that is required to be displayed on a continuous basis. The LCD will interrupt to display speeding messages and or problems being currently experienced by the system when the vehicle is running. The LCD is backlit by means of an integral electroluminescent panel to allow for nighttime viewing.

The Driver Alert Centre (DACM) Extension Harness The driver alert centre extension harness (18) is provided in lengths of 2,3 and 13, 7 metres, the longest designed typically for buses with rear mounted engines.

The DACM extension harness electrically connects the driver alert centre module to the central harness. As seen in Figure 4, one end is terminated with a six position sealed connector (C6) ; the other end is terminated in a six-conductor locking plug (C4). The sealed connector mates to a mating connector of the central harness, the other plugs into header (C3) on the driver alert centre PCB board and is strain-relieved into the driver alert centre module. The extension leads from the central harness, under the instrument panel and across to the driver alert centre location.

The cable is a six-conductor cable composed of 20AWG tinned copper stranded wires. The connector (C6) is a 6 conductor shrouded and sealed locking automotive grade connector. The other end is terminated with a locking 6-conductor plug that mates with the header (C3) on the driver alert centre PCB.

The Ignition Relay The purpose of the ignition relay is to open the vehicle's ignition starter circuit. If the VSM CM has determined that the number of stored violations equals or exceeds a set number of violations stored in its non-volatile memory, the relay is energised and the IGN circuit is therefore open circuit. The relay is integral to the control module assembly PCB. The wires intercepted usually are connected to the start push button or the key switch, and are chosen such that if opened, prevent the vehicle from starting.

Power Connection and Ignition Sense Extensions The power extension provides the means by which power is supplied to the VSM in-vehicle system. The two power lead connect to the vehicle battery plus (+) and (-) points.

The ignition sense is connected to the ignition"ON"point, that is, the point in the vehicle's ignition circuitry that is powered only when the ignition is"ON".

The wire used in a preferred embodiment is 18AWG tinned copper, PVC insulated, 105 C hook-up wire, 2m in length.

The Main Harness (See Figure 4) The main harness (20) is an assembly of special automotive grade connectors interconnected with wires of specific specification and length. The central harness plugs into the CM unit, and is terminated with various connectors for the extension harnesses. Various extension harnesses allow connection of the central harness to the remote sensors, power and ignition etc., the driver alert centre.

The connector designated as C2 is a high performance sealed female connector. It mates with a corresponding male bulkhead mounted header on the CM unit. Various leads terminated at one end in C2 lead out and are terminated into several smaller connectors or terminals.

All other wires of the harness assembly are connected to their specific location and function noted herein or indicated in Figure 4.

Main Control Unit (See Figure 5) The main control unit (22) contains the electronic circuitry that controls the VSM in-vehicle systems. It consists of a black plastic case (24), an electronic printed circuit board including right angle shrouded header (23); black encapsulation compound hermetically seals the entire assembly.

The main function of the VSM system is to monitor the vehicle speed through its sensors, and to determine if the vehicle has exceeded the pre-set speed limit. The VSM control module will, for such an event, record the date, time, and the peak speed at which the vehicle was travelling when the speeding event occurs. The VSM control module will also detect system tampering and will record it as a tamper violation. The tamper violation record contains the date and time at which the tamper violation occurred, along with a code to identify the tampered item. These speeding and tampering violation records will be stored in the VSM control module non-volatile memory.

The VSM monitors the vehicle speed and determines if the vehicle is exceeding the pre-set speed limit. It achieves this by counting the pulses from the speed sensor. At every speed sample event, the VSM acquires a new speed sample and compares it to the speed limit set points which where programmed into its non-volatile memory during calibration. The VSM has two programmed set points: 1. The"Warning Speed"set-point which is the velocity approaching the set speed limit that will warn the driver that the limit is being approached and activate a warning alarm, 2. The"Speed Limit"which is the set point at which the VSM will log violations and activate the violation warning alarm.

In a preferred embodiment, if the vehicle's velocity is below the warning set point, the warning alert alarms are inactive, and the driver alert centre lights are normally"OFF". The driver alert centre may be active with a quick double flash if tampering has been detected.

If the vehicle speed is between the warning and violation speed set points the system will generate intermittent light flashes and short beeps at approximately half-second intervals. This audibly warns the driver that the vehicle is approaching the speed limit set point. When the VSM detects a speed sample which is greater than the violation speed set point, the warning alert alarm and lamp are activated continuously. At this point, the driver can still avoid triggering a violation by immediately slowing, because the VSM determines violations by analysing the speed data over several samples.

If the vehicle exceeds the speed limit for more than a set number of samples the VSM will register a violation. If the speed of the vehicle is reduced below the speed limit before the end of the set number of samples the speed violation will not be captured. It will be understood, however, that depending on law enforcement needs, more, or less, warning may be given to a driver, without departing from the basic mode of operation of the system.

The black plastic case (24) is a custom moulded thermoplastic case. The resin was chosen for its good balance of strength, toughness, electrical properties, surface appearance and chemical resistance.

The case design incorporates three mounting feet (25), with through holes moulded in for screw mounting. The mounting feet are reinforced with flanges. The three mounting feet are set at opposing corners of the case except in the corner where the connector prevents placement. The tripod method is considered appropriate as it is unlikely the surface to which the case would be mounted would be flat.

The electronic circuit board is mounted into the cavity of the case and held in place securely by two screws and is sealed into place with black encapsulating compound.

The printed circuit board material is a high-grade glass epoxy copper clad substrate. The PCB is stuffed with a combination of through hole and surface mount components. The shrouded sealed locking header (C1) is soldered onto the circuit board.

The microprocessor which controls the function of the CM is located on this board.

The connector has a flat mounting flange that sits flat against the inside surface of the CM case at the connector cut out. Sealant is applied between the mounting flange and the inside face of the case around the connector cutout. This seals the area around the connector.

Electrical connections The (C1) electrical connections of the VSM system are as follows: Pin Desiqnation Connection 1 SPDSIG Pulse signal from the speed sensor 2 SPDSUP Speed sensor supply from VSM 3 SPDSENGND Speed supply ground from VSM 4 RPM A RPM sensor signal input to VSM 5 RPM GND RPM sensor ground connection to VSM 6 BATT (-) System, vehicle battery negative connection 7 CAL IN Calibration signal input to VSM 8 BATT (+) System, vehicle battery positive connection to VSM 9 IGNB Ignition interrupt circuit to VSM 10 BRKDETBrake detector input to VSM 11 LMPSW & DETDACM lamp driver circuit connection to VSM 12 LMP SRC DACM power supply connection from VSM 13 IGNA Ignition interrupt circuit to VSM 14 PALRM DACM piezo alarm driver circuit connection to VSM 15 IGN 3 Ignition signal to VSM 16 BATT (-) System, alternate vehicle battery negative connection to VSM 17 TDOOUT Serial communication to DACM from VSM 18 RDI IN Serial communication to VSM from DACM 19 BATT (+) System, alternate vehicle battery positive connection to VSM 20 SPDSENPASSPulse signal from passive speed sensor, (alternate) 21 N/C Reserved 22 N/C Reserved 23 BATT (-) System, alternate vehicle battery negative connection to VSM CIRCUIT DESCRIPTION Block Description The VSM CM is a micro-controller-based design used for monitoring the vehicle speed through an array of sensors and vehicle connections. The CM Unit is a microprocessor based design that is programmed with custom embedded software copyright Ardtech Inc., 1996,1997,1998.

The sensors and certain vehicle connections are connected to the micro-controller through an interface array or active comparison block. The balance of connections is directly connected through to the micro-controller. The flash memory configuration allows the internal software to be upgraded when necessary by means of special equipment and protocols.

The Power Supply Regulator is always active, supplying power to the micro-controller and its dependent peripherals. The Power Supply Regulator is connected to the vehicle battery.

The Real Time Clock (RTC) module is the system clock that is used to accurately keep track of the date and time and is constantly monitored by the micro-controller. The microcontroller uses the RTC to identify the date and time at which violation incidents occur. The RTC date and time are set during the unit calibration. The RTC module is battery backup powered by a separate battery that will keep it working even if the VSM module has been disconnected from the vehicle battery.

The Non Volatile Memory (NVM) is used to store the violation records and the calibration parameters. The microcontroller reads the NVM contents every time a power reset occurs and/or when the VSM control module is first powered up and as needed.

Writing to the NVM takes place whenever there is a violation to store and when the vehicle is being calibrated or re certified. All critical information/data is striped across both memory cells for purposes of redundancy.

The Ignition relay is used to disable the vehicle, by disrupting the ignition key switch circuit continuity. This happens whenever the number of stored violations exceeds a set allowable number. This set number of violations to shut the vehicle off is programmed into the NVM during calibration.

The audio alarm (PALRM) part is used to generate an audible warning at the DACM when the vehicle is approaching the speed limit or when speeding. It is also used during the prove-out cycle to signal that the VSM module is powered up and is operating.

The Auto Calibration (CAL IN) is an input and is used only when the VSM has been primed to receive a calibration or recalibration of the system. This input is used in conjunction with the"Calibration Interface Unit". When the calibration velocity has been reached by the subject vehicle, the calibration interface unit outputs a signal to the CAL IN lead which triggers the VSM control module to capture the current count of the speed pulses and particulars and store that data to the NVM's.

The Speed and the RPM sensors are connected to the microcontroller via the sensor and peripheral interface circuit. These sensors output a continuous train of pulses to the microcontroller which in turn samples these pulses and determines the speed of the vehicle and the engine speed and particulars.

Also connected to the sensor and peripheral interface is the visual warning lamp (LMP-SW and DET signals). It is used to generate a visual warning at the DACM when the vehicle is approaching the speed limit or when speeding. It is also activated during the prove-out cycle to signal that the VSM module is tampered with.

The Ignition sense (IGN~3) signal is used to determine whether the vehicle ignition switch is turned ON or OFF.

The version of the DACM that contains the optional LCD module communicates with the control module (CM) by means of serial communication only and does not require independent connection of the PALRM and LMPSW circuits. This DACM contains its own micro-controller running proprietary embedded software.

The Serial Comm is used to input communication to and from the infrared (IR) serial communication module contained to the DACM and is also used to communicate with VSM Data Reader (DR) and the VSM Data Reader/Eraser Calibration unit (DREC).

DETAILED OPERATION VSM Action on Power-up When power is first applied to the VSM control module, per the installation instructions, either because it is being installed or because the vehicle is being serviced (main battery replaced etc.), the VSM audible alarm (PALRM) will beep with 4 short bursts to indicate that it has powered up and started operation. If the alarm does not activate as described, the VSM, alarm, or wiring may be defective.

Certain data, which is needed for the operation of the unit, is retrieved from the NVM's during a power-up. This includes maximum speed and warning set points, data file pointers, counters, current tamper flags, etc.

After power up, the internal Tel-Tale Truth Table algorithm will execute and determine the current operating state of the VSM system.

The Prove-out Cycle This function is executed when the IGN 3 switch is put into the ON (RUN) position. At this time, the DACM audible alarm (beeper) and visual lamp are activated for a short period. The alarm will activate 4 times if no tampers are present and a single continuous four-second alarm will be emitted if tampers are present.

Monitoring the Vehicle Speed The primary function of the VSM is to monitor the vehicle speed; this is achieved by counting the pulses from the speed sensor. Every sample period, the VSM acquires a new speed sample and compares it to the speed limits (set points) which where programmed into its NVM during calibration. The new VSM speed sample is stored in a buffer that has stored the last several samples. This means that the VSM has the history of the vehicle speed available for analysis by its firmware. The VSM has two programmed set speed detection points: 1. The warning speed set point is the velocity above which the VSM will warn the driver that he is approaching the: 2. Speed limit, which is denoted by the violation speeding set point.

If the vehicle velocity is below the warning set point, the beeper is inactive, and the driver alert centre is normally OFF, (The driver alert centre may be active with quick double flashes if tampers have been detected). If the vehicle speed is between the warning and violation speed set points, the beeper and lamp are both activated with a 50% duty cycle factor based on a frequency of 2 Hz (flash once every 2 seconds). This is to indicate to the driver that the vehicle is approaching the speed limit set point. When the VSM detects a speed sample which is greater than the violation speed set point, the beeper and lamp are activated continuously. At this point, the driver can still avoid triggering a violation by rapidly slowing below the violation speed set point.

Determining that a violation has occurred The VSM uses two methods to issue a violation, Continuous Speeding (CS) and Discontinuous Speeding (DS).

Continuos Speeding (CS) violation This is the primary method of determining whether a violation is occurring. If the vehicle speed exceeds the maximum speed set point for a given number of consecutive samples defined by Maximum CS (programmed during calibration), a violation is issued. If the maximum CS is set to 3, which is the suggested default value, then exceeding the maximum speeding set point for 3 samples or more will trigger a CS violation. The value programmed for"Max CS"should be between 1 and 16 samples. A CS violation will not be registered until Max CS consecutive samples are greater than the"Max CS"set point.

Discontinuous speeding (DS) violation This is a method of determining that a violation should be issued which will discourage drivers from"hovering"close to the maximum speeding set point. By studying how a CS violation is determined, it may be observed that it is possible to avoid causing the VSM to register a violation if the vehicle does not exceed the maximum speed set point for 3 samples. If the driver only exceeds the limit for 2.5 samples and then drops below for 2 more samples, and then repeats this cycle, he can actually travel at an average speed above the maximum speed set point and not trigger a violation.

The DS detection studies the speed history of the vehicle over the last 16 samples, which is stored in the 16-sample speed buffer. With every sample, when a new speed sample is available, the firmware first determines if a CS violation has occurred. If not, and the new sample is above the maximum speed set point, it counts the number of samples of the last 16 which exceeds the maximum speed set point. If this number is equal to the value programmed as Max DS, the firmware indicates that a DS type violation has occurred.

Tracking the"Peak Speed"after a"Violation"occurs once the speed-monitoring module has determined that either a CS or DS violation is occurring, it tracks the peak speed of the vehicle for the time programmed during calibration as "Tracking Time" (time between tickets). For example, if tracking time (time between tickets) is set to 120 seconds, the firmware will track the vehicle peak speed for 120 seconds after first determining that a violation is occurring. At the end of the time interval, the peak speed recorded during the interval will be stored as the violation speed, along with the date and time. The VSM will now start the process of determining if the vehicle is speeding again. It can be seen that the value programmed as tracking time (time between tickets) controls how often it is possible to create a new violation in the VSM violation memory.

Tamper Detection Routine The tamper detection routine executes once every minute on average when the"Run-mode = 0", (the vehicle ignition is off). It determines whether the peripheral devices are connected properly and/or are disconnected. The devices checked and reported back are: 1. IGN~3, Ignition signal"Open Circuit" 2. SPD~SEN, speed sensor"Open Circuit" 3. DACM, driver alert centre"Open circuit" 4. BATT (+), Vehicle battery connection to module is"Open circuit" 5. IGN RELAY, Ignition circuits disrupter relay"Open circuit". (Applies to revision"A"only).

N. B. All items can be adjusted to be reported as service flags and not tampers.

When a new tamper detection has been detected it will be stored in the violation memory along with the date and time of its occurrence. These tamper records will increment the violation counter just as a speeding violation does.

The occurrence of a tamper will sets a"Tamper"flag which causes the driver alert centre to continuously flash in a specific pattern (fast double flash), when run-mode = 1, and the vehicle speed is below the warning speed set-point. In addition, the beeper will sound continuously for-5 seconds during the diagnostic prove-out cycle to indicate to the driver that one or more sensors/peripherals are not responding as expected. The tamper flag will be cleared when any violation records are read from the VSM module while using a DR or DREC.

The Vehicle Auto Calibration The Auto Calibration process is initialised by the DREC system to put the VSM control module in the"Auto Cal'mode. After the calibration parameters are entered in the DREC host computer and written to the in-vehicle CM NVM, (as described in the DREC User's Manual), the vehicle is to be prepared for the road calibration.

The VSM system is calibrated by running the vehicle at the calibration speed. Various techniques both mobile and stationary exist for determining the exact apparent speed of the vehicle. Such techniques include stationary speed dynamometers, motion and speed sensors of which are mounted on the vehicle and operate independent of the vehicles own instrumentation, and also various other fifth wheels, radar units etc.

The calibration interface unit is configured to interface with the sensing equipment. It outputs a signal at the precise instant the vehicle achieves the calibration reference velocity. The Calibration Interface will signal the VSM through the"Auto-Cal"signal wire of the same. At this instance the current speed and RPM sensor pulse data is recorded to non-volatile memory NVM as an absolute value. It will then calculate the pulse count for other speeds and store them in a table in the non-volatile memory for later reference.

PERIPHERAL SUPPORT SYSTEMS The Data Reader (See Figures 6 and 7) The Data Reader (DR) (26), unit is a portable hand-held unit that allows law enforcement personnel to access the speeding violations stored in the in-vehicle VSM control module. The DR user can issue tickets against any of those stored nonticketed violations. At the end of the access session, the DR sends the ticket information back to the CM which stores this data in its NVM.

The DR is an integrated assembly that consists of a compact upper and lower plastic housing, a rechargeable battery pack and printed circuit board assemblies (PCB). The printed circuit board assemblies include the integrated Keyboard/ Micro-controller/and IR assembly, and the LCD assembly. The front face of the DR (not shown) includes the infrared window for the IR module that is used to communicate with the invehicle system.

The keypad (30) is arranged as a 4 X 7 contact matrix assembly. The ENTER key comprises two locations thereby reducing the push-button key count to twenty seven. The keypad is directly interconnected to the micro-controller assembly.

The keypad (30) is fitted with a night viewing backlit system.

The backlighting will be turned on automatically by the microcontroller whenever the light detection circuit detects insufficient ambient light.

The micro-controller and IR PCB assembly contains the microcontroller (31) and Infrared communication module (32).

The micro-controller is a microprocessor based design that is programmed with custom embedded software copyright Ardtech Inc., 1996,1997,1998.

The data reader includes an LCD assembly with an LCD display (33), LCD driver and an LCD backlighting system (34). The LCD is an application specific custom design.

The housing design incorporates appropriate bracing, mounting bosses, alignment ribs, and additional locating features to hold the circuit boards and the silicone membrane keypad in place.

The DR case is made of high performance engineering thermoplastics. The case is assembled from a top (27) and bottom (28) section. A tongue and groove runs along the mating edges. This aligns the two sections during assembly, serves as a barrier to moisture and dust and hides the parting lines of the two halves. The top half is characterised by the individual key cutouts, the large cutout for the LCD display and ambient light detector. The inside of the top section features ribs and mounting bosses for the purposes of affixing the various PCB assemblies. Around each keyhole is a surrounding thin-wall rib. When the keyboard assembly is fastened into place, the rib is pressed into the silicone surrounding each pad. This forms a gasket around each key that provides protection against dust and moisture. The case of the DR unit is designed to house and protect the internal electronics from moisture and dust.

User Keypad.

The keypad (30) is moulded from silicone. Under each key is a small carbon low resistance formed pill that is used to provide a switch closure contact when depressed to the keypad PCB copper etched pattern.

The graphics and text is applied to the tops of the keys using a screened ink process, after which, are coated with a hard layer of plastic encapsulation. This gives the keypad a "hardtop"feel. Alignment depressions moulded into the top surface of the keypad align with corresponding pins moulded onto the bottom surface of the upper case. Mechanical depressions are moulded into the underside of the keypad to clear surface mounted Leeds'for backlighting of the keys.

In a preferred embodiment, the keypad array is divided into 7 rows and 4 columns, referring to Figure 6.

The battery pack or power source for the DR is a rechargeable flat pack type assembly. The battery pack is removable, and snaps and locks into place at the bottom surface of the lower case. Thus, an extra battery can be plugged in for extended use.

The Liquid Crvstal Display Referring to Figure 7, in a preferred embodiment, the Liquid Crystal Display, (LCD) consists of two lines, each of which is twelve characters long and eight graphic icons as shown in Figure 10, and as set out below in Table II.

TABLE II symbol Function Description GR1 Clock Clock graphic symbol GR2 Comm communication graphic symbol GR3 NO TCKT No ticket graphic symbol GR4 TCKT Ticket graphic symbol GR5 SPEED Speed graphic symbol GR6 Violation File Violation file graphic symbol GR7 PIN PIN graphic symbol CH1 TIME HH: MM Time of day, character display area CH2 VIOLATION Violation number 01-99 display area CH3 SPEED/PIN Speed/PIN display area CH4 DATE DD: MMDate characters display area CH5 Comm Communication direction display area The LCD (33) is bonded to the backlighting assembly (34) with thin water clear double-sided tape. This assembly is in turn bonded to the LCD circuit board with 3mm double-sided foam tape. This arrangement isolates the LCD glass (39) from any violent shock and vibration.

The DR hand unit incorporates backlighting for the keypad and LCD. This is controlled via the micro-controller as earlier mentioned. The light from the LED's are transmitted into the translucent silicone of the keypad, which acts as a light pipe. This distributes the light around the keypad buttons.

The LCD is backlit by conventional methods, i. e., electroluminescence, etc.

The infrared assembly is responsible for the communications with the VSM in-vehicle system. The infrared module is compatible with the infrared module in both the DACM and DREC.

The light is projected outwards through the infrared lens (32).

The contacts located to the bottom of the lower DR housing is the means by which data transfers out of the DR to DRDB and charging of the DR battery is achieved, when plugged to the DRDB unit. The DR unit is charged whenever it is inserted into the DRDB slot. The charge circuit is a"smart"charger, i. e.; it discharges the batteries and then charges them at a fast rate thereby actually prolonging the life of the battery.

The DR has provision to automatically monitor the status of its internal battery. When the DR detects that the battery voltage drops to a pre-determined level, it will display "Battery Low"on the LCD and displays the message for 30 seconds after which will turn off. The unit should be returned to the DRDB control station to recharge the battery and to transfer the data stored in its non-volatile memory. A spare battery may be plugged into the unit.

The DR incorporates a battery saver function, which saves the batteries from being depleted if the unit is inadvertently left on or is accidentally turned on. If the user does not press any key within a three-minute period, the unit will abort the current operation and shutdown. The user must turn the unit ON and go through the PIN verification cycle to commence using the unit.

Security Features of the Data Reader There are several security features that were designed into the software of the system of the present invention to ensure proper use and prevent unauthorised usage.

In a preferred embodiment, the main security feature that protects the DR against unauthorised use is the Personal Identification Number (PIN) which is assigned to the user at the time the DR is taken from the Data Reader Docking Bay (DRDB).

For proper operation after a DR has been successfully issued from the DRDB, the user must enter, via the keypad, their PIN number. The DR gives the officer three chances to enter the PIN. After three attempts the unit will shut off for about three minutes, after which another three chances will be given to the user. If the user fails to enter the correct PIN after the second round of three attempts, the DR will be rendered inoperable. In such a case, the unit must be returned to the DRDB to be reinitialised by an authorised superior.

Preferably, any DR unit, even those that are to be used for the first time must be plugged in the DRDB control station to be initialised with a user PIN and the user badge number before it can be re-used.

When the DR unit release process is started, the unit will be checked to see if its battery is fully charged or not. The DRDB controller will not release any DR that has not had its batteries fully re-charged. The batteries require approximately two hours to complete the charge cycle.

The Data Reader Docking Bay The Data Reader Docking Bay (DRDB) System (Figure 9) is designed, as part of the Vehicle Speed Monitoring system (VSM). The DRDB serves as a station for recharging the Data Reader (DR) units'battery and for downloading or transferring stored data of the DR through to the host desktop computer via the DRDB integral controller. The DRDB system consists of a compact control station (40), with a number of pockets or slots, for purpose of plugging DR units into. Each slot provides a power source to recharge the DR battery and communication contact points that connect with the DR units microcontroller communication port. The DRDB control station is connected to a host desktop computer through a standard RS232C serial port. The host custom application software allows the user to interact with the DRDB control station. The custom DRDB embedded software is copyright Ardtech Inc., 1996, 1997,1998.

In a preferred embodiment of the present invention, the DRDB consists of a"custom enclosure"rack mountable assembly (42), able to hold several cage assemblies (43). The DR pocket modules are fastened into a cage assembly by four front captive screws. The cage assembly is then fastened into the rack assembly.

Daisy-chained power and data harnesses are connected to polarised locking mating connectors on the PCBs mounted onto each docking bay module. If one of the docking bay modules is in need of service, the power and data harnesses can be disconnected from the back of the module, four screws are loosened at the front panel of the assembly and the module is slid out. The rest of the DRDB will remain functional with a unit or several units removed, or, a replacement module can be slid into its place and reconnected accordingly.

Each DRDB complete assembly rack contains its own Controller Module. The PC interface cable is plugged into an RS-232 port at the back of this unit. The daisy-chained data and power harnesses are also connected to this module. The assembly additionally has the provision to accommodate the system power supply to one of the free panel openings not occupied by a DR module. The entire DRDB rack assembly is enclosed in a standard metal housing.

TheDockinc Bay The docking bay pockets (See Figure 9A) are fabricated from high performance engineering thermoplastic; moulded in custom tooling.

The PCB for the docking bay pocket contains six spring loaded contacts that mate up with the six contacts of the DR, two contacts for the purpose of recharging the batteries, two are for data communication and the balance are for battery temperature monitoring through the recharge cycle. Two LED's are located to a visible forward facing surface indicating status of the particular DR,"BATTERY CHARGING"or"DATA TRANSFER".

The controller card (not illustrated) of the DRDB contains the circuitry that directs the data transfer among the up to 128+ addressable DR's while plugged to the DRDB. The DRDB assembly additionally has the provision to accommodate the system controller assembly to one of the free panel openings not occupied by a DR pocket or power supply. The front face or front panel of the controller card contains two LED's to indicate power and status of communication. The controller card assembly is fastened into the rack by the front panel with four screws.

The docking bay pockets are loaded into the rack and secured in place with screws, free panel openings not occupied by a DR pocket or other items are covered with blank front covers that are held in place with four screws as well. The power supply harness and data transfer harness is daisy-chained to the appropriate connectors at the back of each module. The harnesses are designed to have enough distance between the connectors so that a module can be slid out of the rack with the connectors attached for ease of service. This may be required if the rack is mounted into a larger rack with an enclosed back.

The DRDB Software All information pertaining to the description and operation of the custom application software is detailed to the respective document.

The Data Reader/Eraser Calibration Unit, (DREC) System.

The Data Reader/Eraser Unit is a microprocessor based design that is programmed with custom embedded software copyright Ardtech Inc., 1996,1997,1998.

The DREC (See Figure 10) is designed, as part of the VSM System, to serve as a tool allowing an authorised individual the ability to initialise, calibrate and verify an in vehicle VSM System. The DREC system can also read, download, write and/or clear, any of the stored information in the in-vehicle VSM system.

The DREC unit contains (not illustrated) a PCB assembly with controlling circuitry, and the IR module. The PCB is housed in an extruded aluminium case, the ends are capped by plastic end bezels and aluminium face plates. The rear face accommodates the serial connector for the computer, LED indicator lamps for power and data transfer, and power connector. The front face accommodates the IR lens.

Power for the unit is derived from either the vehicle battery and/or the Calibration Interface Unit.

The DREC unit is connected through to a host laptop computer by means of standard RS232C serial communication port.

The DREC Software All information pertaining to the description and operation of the custom application software is detailed to the respective document.

Calibration systems The calibration system used for the VSM system calibration process consists of a"Reference Speed Sensor"unit (57), (see Figure 11) and an interface (Calibration Interface) unit (58) (see Figure 12). The reference speed sensor outputs a compatible pulse train signal, which varies proportionally with the true ground speed of the vehicle. This signal is detected and processed by the calibration interface unit. The interface unit, known as the Calibration Interface Unit, compares this signal against an internal reference setting and outputs a calibration command pulse to the in-vehicle VSM system. This reference point is the calculated value that the reference speed sensor will output when the vehicle's velocity is, for instance, exactly 80.0 Km/h.

The Reference Speed 8ensor The reference sensor (57) used to calibrate each in-vehicle system is a small microwave based unit. The sensor functions on the basis of the"Doppler"effect by using the frequency shift of a wave reflected by a moving surface. The advantages of this non-contact system over other ground contact methods is that it is slip free, i. e., it is unaffected by gravel, dirt or wet roads, and it compensates for vehicle pitch movements. The sensor is attached to the outside of the vehicle using suction clamps or magnetic holders. A variety of mounting bars and articulated knuckle clamps aid in the placement of the sensor. Cables connect the sensor to the calibrator and the power source-10.5 Vdc to 30 V dc. The power is taken from the vehicles own power system.

The sensor is supplied with software, which allows an operator to view the output signal of the sensor in Km/h or M/h, and monitor acceleration and distance travelled. The software also allows for calibration of the system.

Since the unit outputs a fixed number of pulses per unit distance travelled, the calibration takes place over a reference length of road. A vehicle with the sensor mounted to the body is driven a fixed reference distance and the number of pulses counted. The number of pulses per metre is calculated and this becomes the reference set point.

The speed sensor is a known device, which is obtained, along with the software and mounting fixtures from DATRON MESSTECHNIK.

The DATRON system for the purpose of calibration is by no means the only method for the purpose of investigating an invehicle VSM system to receive calibration etc., but is one of many methods to achieve the same required conclusion.

The Calibration Interface Unit. (CIU) Figures 12 and 12A) The Calibration Interface Unit is a microprocessor based design that is programmed with custom embedded software copyright Ardtech Inc., 1996,1997,1998.

The calibration interface unit derives its signal from a reference calibration speed sensor system. These signals are compared to the internal reference point settings. At correlation, it outputs a signal to the in-vehicle system to store within the non-volatile memory, the particulars and data collected at that instant, to be used as reference and operational parameters.

The calibrator is powered from the vehicle's power system. A power output socket 68 and binding posts 69 supply power from the calibrator to the other equipment, such as the DREC system.

The calibrator is made from a die cast aluminium box (59). The top lid (60) is reference labelled (70), drilled and punched to accommodate connectors, switches and handles. The box is punched to accommodate power sockets, power cables and binding posts. The PCB (62) is attached through stand-offs to the top lid (60), as is the DB9 computer connector (63), the LED indicator (64) and the main power switch (65). The audio alarm (66) also projects through the top lid.

The power cable (67) is a 4-metre line cord with a red and black battery alligator clip terminating the two conductors.

The cable is a rubber jacketed grease resistant grade cab tire configuration. A fluid tight box connector clamps the cable to the box.

The front panel indicators indicate power and data transfer from the Reference Speed Sensor System, and display the current calibration status. The power indicator lights when power is applied to the calibrator and the power switch is on.

The data transfer indicator flickers when a signal is being received from the reference speed sensor system.

This indicator is useful as a gross indication of whether the system is connected properly. The calibration signal lights when the vehicle has obtained the calibration reference speed and the VSM system has been calibrated. The audio alarm is also activated at this point.

BlockDiagrams Figure 13, Block diagram, VSM Control Module Figure 14, Block diagram, DACM w/LCD Figure 15, Block diagram, VSM DR unit Figure 16, Block diagram, DREC unit Figure 17 Block diagram, VSM CI unit Figure 18, Block diagram, VSM Calibration unit DESCRIPTION OF FIGURES (BLOCK DIAGRAMS) Block diagrams, VSM Control Module Block diagram, VSM Control Module, Figure 13 as illustrated is a microprocessor based unit that contains application specific embedded software. The heart of the system is based on a micro-controller surrounded with peripheral support circuitry.

These peripherals consist of a"Power Supply Regulator"that provides the system with a regulated system voltage independent of the changing vehicle voltage, all of which is protected by a common"Protection Circuit".

The"Peripheral Interface Comparator Block"is used to interface the analogue sensors and convert the signals being received to a compatible format for the micro-controller. The PICB is controlled by the micro-controller by means of a "Power Supply Switch". This switch, when turned"OFF", does not provide any power to the PICB thereby reducing the system quiescent current to minimal levels and conserving energy.

The"IGN Buffer"consists primarily of a differentiating circuit with hysteresis to provide the micro-controller only valid transitions of the vehicle ignition signal.

The"IGN Relay", is used to electrically"Open Circuit"the start switch continuity of the vehicle ignition starter circuit. The relay is only energised when the vehicle has accumulated the set number of possible stored violations-as explained earlier.

The"Real Time Clock", is the means of how the VSM keeps track of time. The RTC is accurate to within 6 seconds per month running time. The RTC is powered by both the internal system power regulator and when needed, the"Backup Battery". The RTC/backup battery combination can be left unpowered on the shelf for up to 5 years and still maintain accuracy.

The"NVMS", Non Volatile Memory array is used by the VSM micro-controller to store operational, calibration, tamper flags and violations. The array is non-volatile-meaning that no backup battery is required for the memory array to retain stored data. Both memories are connected to the same serial bus as the RTC. Each device is individually addressed and can be bypassed if found to be defective. The data that is stored to the NVM's is split to two categories, critical and noncritical. The critical data is saved or mirrored to both memory cells called data striping. Noncritical data resides to whichever memory has been selected for the particular item.

Block diagram, VSM Driver Alert Centre Module w/Optional Lamp Block diagram, DACM w/Optional Lamp, is the visual and audible portion of the VSM in-vehicle system. Control of both audible and visual alarm is controlled via the VSM CM.

The remaining circuitry is dedicated to infrared communication supporte by the IR System Interface and IR Transceiver. The on-board IR communication is the means that is used by all of the support subsystems to communicate with each other.

The"Power Supply Control Circuit"provides the DACM with a regulated system voltage independent of the changing vehicle voltage, all of which is protected by a common"Protection Circuit". The power for the VSM CM is derived through the wire harness.

The"Optional Array of LED's"is used as the forward facing lamp to visually indicate outside of the vehicle, the status of the VSM system. For the user, there is internal indicator located at the front face of the DACM.

Block diagram, VSM DR Unit, (Data Reader) Block diagram, VSM DR Unit, (Data Reader), Figure 15 as illustrated is a micro-processor based unit that contains application specific embedded software. The heart of the system is based on a micro-controller surrounded with peripheral support circuitry. These peripherals consist of a "Power Supply Regulator"that provides the system with a regulated system voltage independent of the changing battery voltage, all of which is protected by a common"Protection Circuit".

The peripheral circuitry consists of an"IR-Interface Transceiver","Ambient Light Detection"circuit, Non Volatile Memory, LCD (Liquid Crystal Display) and the user"Keypad".

The IR Interface Transceiver is the same as that of the DACM and is the means for communication between the various subsystems.

The NVM memory array is similar to that of the VSM CM per function and operation.

The"LCD"assembly is based on a VLSI (Very Large Scale Integrated Circuit). The communication between the resident micro-controller and the LCD is via parallel data communication. Contrast is controlled locally by means of user ajustable setting and augmented by an internal circuit thermally tracking each adjusted range. Backlighting is provided for nighttime use.

The"Keypad"is the means how a user interfaces with the DR.

Details pertaining to the description and use of the keypad, is explained herein.

The DR is a battery-powered unit. Additionally, the DR has built in circuitry that allows for continuous measurement of the removable battery pack when in place. Through application specific embedded software the DR determines whether the unit has enough battery power available prior to commencing a communication session or any high power demanding function.

The total of the circuitry is contained to 2 printed circuit assemblies interconnected via flexible multi-conductor connector strips. The keypad is located to one side of the PCB while the second side contains all of the balance of components excluding the LCD assembly, which is a selfcontained assembly.

Block diagram, VIN DRDB Controller Unit Block diagram, VSM DRDB Controller Unit, Figure 16 as illustrated is a micro-processor based unit that contains application specific embedded software. The heart of the system is based on a micro-controller surrounded with peripheral support circuitry. These peripherals consist of a "Power Supply Regulator"that provides the system with a regulated system voltage independent of the changing battery voltage, all of which is protected by a common"Protection Circuit".

The"Communication Interface"section is directly connected to the DR through wired connection. There is no infrared communication support required for communicating with the DR units. Transistor buffering circuits are provided to each pocket communication point to a DR as not to overload the common serial communication bus.

The"RS232C Interface Transceiver"is the means for the connection of the DRDB System to the personal desktop computer running the DRDB application specific software.

There are two LED's located to the front panel of each module which serve as"POWER"and"Communication"status indicators.

The"Communication"LED flashes when data is either being received or transmitted to and from the DRDB.

Block diagram, VSM DREC Controller Unit Block diagram, VSM DREC Controller Unit, Figure 17 as illustrated is a micro-processor based unit that contains application specific embedded software. The heart of the system is based on a micro-controller surrounded with peripheral support circuitry. These peripherals consist of a "Power Supply Regulator"that provides the system with a regulated system voltage independent of the changing battery voltage, all of which is protected by a common"Protection Circuit".

The"IR Interface Transceiver"is the same as that of the DACM and DR units and is the means for communication between the various sub-systems.

The"RS232C Interface Transceiver"allows for the connection of the DREC System to a personal desktop computer running the DREC application specific software.

There are two LED's located to the front panel, which serve as "POWER"and"Communication"status indicators. The "Communication"LED flashes when data is either being received or transmitted to and from the DREC.

Block diagram, VSM Calibration Interface Unit Block diagram, VSM Calibration Interface Unit (CIU), Figure 18 as illustrated is a microprocessor based unit that contains application specific embedded software. The heart of the system is based on a micro-controller surrounded with peripheral support circuitry. These peripherals consist of a "Power Supply Regulator"that provides the system with a regulated system voltage independent of the changing vehicle battery voltage, all of which is protected by a common "Protection Circuit".

The"RS232C Connector"is the means that allows for the connection of the Reference Speed Sensor System (calibration system) to be connected. This provides pulse/distance data to the CIU.

There are three LED's located to the front panel, which serve as"POWER"and"DATA Activity"and"Calibration"indicators.

The"DATA Activity"LED flashes when data is being received from the Calibration System. The"Calibration"indicator lights when the calibration of the subject VSM system occurs, and the"POWER"indicator is to indicate when power is present to the CIU and is switched ON.

The"CAL~O/P"is the connection port to the VSM CM, to which the CIU calibration lead wire is connected. A signal is generated by the CIU when the calibration velocity is achieved.

The"Calibration Offset DIP Switches", is set when the CIU is itself being calibrated with the reference speed sensor system assuring compatibility with all types of reference systems.

These switches are set providing an offset to the internal microprocessor and are left in the calibrated offset position and should not be changed unless during the process of calibrator system re-calibration.

Summary It is to be understood that the examples described above and throughout this document are not meant to limit the scope of the present invention. It is expected that numerous variants will be obvious to the person skilled in the field to which the present invention pertains without any departure from the spirit of the invention. The appended claims, properly construed, form the only limitation upon the scope of the invention.

All the previously mentioned custom embedded software is copyright Ardtech Inc., 1996,1997,1998, as is the custom application software. MS Windows is a product of the Microsoft Corporation.

Claims (26)

1. THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS : 1. Apparatus for monitoring vehicle speed, and detecting episodes of vehicle speed in excess of a predetermined maximum speed, including: a) a first subsystem for mounting on a vehicle to monitor and record vehicle speed related information ; b) a transportable device for receiving and storing information recorded by said first subsystem; and

   c) a second subsystem for receiving information stored by said transportable device.
2. 2. Apparatus as claimed in claim 1, wherein said first subsystem comprises sensing means for sensing the speed of a vehicle, and outputting a signal representing said speed; and processor means for recording vehicle speed related information, having an input for receiving the signal from said speed sensing means.
3. 3. Apparatus as claimed in claim 2, wherein said first subsystem further comprises output means associated with said processor means, for permitting vehicle speed related information stored in said processor means to be output to a said transportable device.
4. 4. Apparatus as claimed in claim 2 or 3, wherein said first subsystem further includes a warning device having an input connected to an output from said processor means, and being actuatable by said processor means to produce a visually or audibly sensible signal.
5. 5. Apparatus as claimed in claim 4, wherein said warning device is a beacon mountable on or in a vehicle for viewing from outside said vehicle.
6. 6. Apparatus as claimed in claim 5, wherein said beacon includes audible warning means for warning a driver that vehicle speed is in excess of a predetermined allowable maximum.
7. 7. Apparatus as claimed in any one of claims 2-6 wherein said first subsystem includes an ignition relay having an input for receiving a signal from said processor means, said processor means being programmable to actuate said ignition relay to prevent operation of said vehicle, in predetermined circumstances relating to detected episodes of vehicle speed in excess of a predetermined maximum speed.
8. 8. Apparatus as claimed in any one of claims 2-7, wherein said speed sensor is connected to the speedometer cable of a said vehicle.
9. 9. Apparatus as claimed in any one of claims 1-8, wherein said first subsystem includes an RPM sensor for sensing the engine speed of a said vehicle, and outputting engine speed information to said processor means, said processor means including comparator means for comparing engine speed and vehicle speed, to monitor the accuracy of said vehicle speed sensor.
10. 10. Apparatus wherein said processor means comprises a control module having inputs at least from said vehicle speed sensor, and said RPM sensor, and outputs at least to said warning beacon and said ignition relay.
11. 11. Apparatus as claimed in claim 10, wherein said control module includes communication means for outputting a signal to a transportable device, and receiving a signal from a transportable device.
12. 12. Apparatus as claimed in claim 11, wherein said means for outputting a signal to a transportable device and receiving a signal therefrom is an infrared serial communication module.
13. 13. An apparatus as claimed in any one of claims 10,11 or 12, wherein said control module includes power input means for receiving power from the electrical system of a said vehicle, and power output means for providing electrical power to all parts of said first subsystem.
14. 14. An apparatus as claimed in any one of claims 2-11, wherein said transportable device comprises a hand held device that is provided with means for communicating with said first subsystem.
15. 15. An apparatus as claimed in claim 12 or 13, wherein said transportable device comprises a hand held device that is provided with a infrared communications module for communicating with said controller module.
16. 16. An apparatus as claimed in claim 14 or 15, wherein said transportable device includes a keyboard, a screen and a microcontroller, to permit a user thereof to visually inspect vehicle speed related information received from the control module of a vehicle, store said information, and select from predetermined options the manner of proceeding to deal with an episode of excessive speed.
17. 17. An apparatus as claimed in claim 16, wherein said transportable device is provided with a rechargeable battery.
18. 18. An apparatus as claimed in claim 17, wherein said screen is an LCD for visually presenting graphical and/or alphanumeric symbols relating to vehicle speed related information, and said predetermined options.
19. 19. An apparatus as claimed in claim 18, wherein said keyboard includes keys for selecting information and/or options displayed on said screen.
20. 20. An apparatus as claimed in claim 19, wherein a light detection circuit is provided in said transportable device, connected to a backlighting LCD system for illuminating said keyboard in connection of low ambient light.
21. 21. An apparatus as claimed in any one of claims 1-16, wherein said second subsystem comprises means for interfacing with said transportable devices, and means for storing vehicle speed related information downloaded from said transportable devices.
22. 22. An apparatus as claimed in any one of claims 17-20, wherein said second subsystem comprises means for interfacing with said transportable devices, and means for storing vehicle speed related information downloaded from said transportable devices.
23. 23. An apparatus as claimed in claim 22, wherein said second subsystem includes an assembly for receiving one or more of said transportable devices in individual docking stations, each of which is provided with means for recharging the battery of a said transportable device, and communication means for receiving a signal from a said transportable device, and sending a signal to a transportable device.
24. 24. An apparatus as claimed in claim 23, wherein a plurality of said docking stations are arranged as a docking assembly and are connected to a computer for storing information downloaded from transportable devices.
25. 25. An apparatus as claimed in any of claims 1-24, further including: (d) a calibration subsystem.
26. 26. An apparatus as claimed in claim 25, wherein said calibration subsystem includes a mountable/demountable reference speed sensor for sensing ground speed of a vehicle, -a processor having a signal input from said reference speed sensor and an output to said first subsystem.