GB2343017A

GB2343017A - Control system for restricting vehicle performance

Info

Publication number: GB2343017A
Application number: GB9823322A
Authority: GB
Inventors: Roy Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-10-23
Filing date: 1998-10-23
Publication date: 2000-04-26
Anticipated expiration: 2018-10-23
Also published as: GB9823322D0; GB2343017B

Abstract

A control system for restricting a vehicle's speed to statutory limits comprises means by which the driver can select the appropriate speed limit from a set of speed limits. Each speed limit has associated with it a maximum acceleration limit, and the vehicle is constrained to operate below both the selected maximum speed limit and the associated acceleration limit. The instantaneous speed and acceleration of the vehicle are determined, and then engine management and braking systems are operated to limit the vehicle accordingly. Furthermore, each set speed limit may have associated with it a different relationship relating accelerator pedal travel to energy input to the engine. A device for allowing the driver to increment or decrement the speed limit in steps is also disclosed, as is a feature allowing the driver to input information to the system using his voice. Remote control and data transmission features are also disclosed.

Description

CONTROL SYSTEMS FOR VEHICLES This invention relates to a control system for vehicles.

Soon after their inception the speed of motor cars was controlled by having a man walk before them carrying a red flag. Since this control was dropped, vehicles have been produced with ever increasing power outputs, so that today nearly all cars are capable of 140 kph (87 mph) many can accelerate from rest to 100 kph (62 mph) in less than 10 seconds and power output greater than 110 kw (148 hp) are common.

Additionally, suspensions are being continually improved, internal noise levels are being reduced and audio systems are now excellent and powerful.

All the above makes it much more difficult for good drivers to maintain a safe speed and keep within statutory limits. It is also necessary to apply pressure to bad drivers to obey the law. It is now time to bring back a modem version of the red flag and this invention will achieve it.

According to one of the varied aspects of the present invention, there is provided within a vehicle a system that provides the driver of the vehicle with a stepped manual control which sets differing speed and associated acceleration limits for the vehicle.

The instantaneous speed and acceleration of the vehicle may be measured, and the vehicle may then be controlled only to operate at or below the limits set. The system may include display information of the speed limit set for the driver and for other vehicles. Furthermore the law between accelerator pedal travel and energy input to the engine may be changed for each set speed limit. Remote control may be a further development.

A system according to the invention offers the possibility of : i) saving lives ii) reducing injuries iii) reducing accidents iv) reducing pollution and energy consumption v) reducing road rage vi) bringing about a fundamental change in driver attitude for the better vii) allowing drivers to concentrate on other aspects of their driving, knowing that their set speed and acceleration limits cannot be exceeded.

A specific embodiment of the system according to the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a block schematic drawing of the system of the invention; and Figure 2 illustrates input-output power laws embodied in the system of Fig 1.

Referring to Figure 1, a central processing unit 1 accepts information from a driver's control unit 2 and a data unit 3 and provides information to a command unit 4 and to display units 5 and 6.

The driver's control unit 2 is a device which allows the driver to increment or decrement in steps the speed limits that the vehicle cannot exceed. Inherent in selecting a speed limit, a managed acceleration limit will be imposed by the system.

It could include a system cancel device. A future remote control unit could be added.

This device could take the form of two push buttons on the end of a stalk close to the steering wheel and operated by the fingers, or a microphone with amplifier could input the required information from the driver's voice.

The data unit 3 accepts data relating to the instantaneous speed and acceleration/deceleration of the vehicle and passes them to the central processing unit. Additional information could relate to the gear ratio in use and to any slip between the vehicle's wheels and the ground on which it is travelling.

The command unit 4 feeds control information to the engine and braking systems of the vehicle to ensure that for the specific speed set by the driver's control unit: i) if the present speed is above the manual setting, then the vehicle will be safely decelerated to the maximum speed of that setting, and ii) when the speed of the vehicle is at or below the manual setting, it cannot subsequently accelerate above it, and iii) for any speed limit set, there will be a corresponding maximum acceleration limit permitted also.

It is anticipated that a device (part of the command unit) will be required between the accelerator pedal and the energy input to the engine. At present, certainly for cable systems and probably for non-cable systems there is a one-to-one correspondence between pedal travel and energy input. With this system it will be possible for the law between pedal travel and energy input to be changed for each set speed limit, providing better control of speed below these limits. Figure 2 covers one possibility.

For the display units, two different units are considered. The driver's display 5 would provide the driver with information of the speed limit he has set. This could be by visible, audible and/or tactile means. Additionally information could be presented on the acceleration/deceleration necessary to achieve the setting selected. The external display 6 could allow following drivers to be aware of the speed limit set It is envisaged that the vehicle displays the limit at the rear of the vehicle. This could indicate the limit setting in numerals, characters or colour from an agreed set of speed limits.

Data could also be fed to a remote receiver via a local transmitter should this be required in the future.

For the Stepped Speed Limits, statutory speed limits exist in the United Kingdom at approximately 48.3,64.4,80.5,96.6 and 112.7 kph (30,40,50,60 and 70 mph) and additionally 32.2 kph (20 mph) is considered a safe maximum speed near schools.

Differing sets of limits would apply in other countries. These speed limits could be considered as the incremental stepped speed limits for the system. Approximate acceleration minimum times from rest to these velocity limits are suggested in the table below. The form of the acceleration curves will need to be defined so that all vehicles capable of exceeding these performance criteria will have the same performance when the speed limit is set.

Stepped Speed Limits Minimum Acceleration Times from Rest kph secs 32.2 3 48.3 4 64.4 7 80.5 10 96.6 14 112.7 15 For braking, as described above in the command unit 4, this will, in most cases, be necessary to decelerate the road vehicle to the limit set by the driver's control unit with the engine management system also being involved. If the driver takes no or too little braking action it is proposed that the system will take over or assist the declaration action. The most severe legal case in practice is to reduce speed from 112.7 to 48.3 kph (70 to 30 mph). With a deceleration rate of 0. 5g this will take about 3.5 seconds the vehicle covering about 80 metres in the process. Deceleration rates would be less severe when vehicle speeds are lower. Automatic braking will also be necessary at times to control downhill speeds within the limit set.

At all times during its use the system has to be successfully integrated with the normal accelerator and brake functions of the vehicle, only coming into operation to achieve and maintain the limits set by the driver's control.

It should be noted that the system will still permit installed engine power outputs up to the maximum to be used for hill starts and/or maximum loads at altitude as long as any set speed and acceleration limit is not exceeded.

It is envisaged that when the engine of the vehicle is started, the 48. 3 kph (30 mph) speed limit is automatically engaged, but this is not essential to the working of the system.

Claims

CLAIMS CONTROL SYSTEMS FOR VEHICLES 1. Control Systems for Vehicles which cover a number of elements to restrict performance in a set of steps; namely speed limits each with an associated maximum acceleration limit; under driver's and/or remote control; with driver's display, rear of vehicle display, remote display; with changed laws relating accelerator pedal travel to energy input to the engine for each set speed limit; with the instantaneous speed and acceleration of the vehicle being measured and the engine management and braking systems being operated on to control the vehicle only to operate at or below the limit set.
2. A specific embodiment of the system including all the elements in Claim 1 and as described in the Description above.
3. A control system containing elements of Claims 1 and 2 that provides a driver of a vehicle with a stepped manual control which sets differing speed limits each with an associated maximum acceleration limit for a vehicle.
4. A control system as in Claim 3 with additionally a driver's display.
5. A control system as in Claim 4 with additionally a display at the rear of the vehicle.
6. A control system as in Claim 5 with additionally where the law relating acceleration pedal travel to energy input to the engine is changed for each set speed limit.
7. A control system as in Claim 4 with additionally where the law relating acceleration pedal travel to energy input to the engine is changed for each set speed limit.
8. An element of a control system, a driver's control unit which allows the driver to increment or decrement in steps the speed limits that the vehicle cannot exceed and which can take the form of two push buttons on the end of a stalk close to the steering wheel and operated by the fingers, or a microphone with amplifier can input the required information from the driver's voice.
9. An element of a control system, a driver's display which provides the driver with information of the speed limit he has set which can be by visible, audible and/or tactile means.
10. An element of a control system, a display at the rear of the vehicle to allow following drivers to be aware of the speed limit set which can indicate the limit set in numerals, characters or colour from an agreed set of speed limits.
11. An element of a control system, where the law relating acceleration pedal travel to energy input to the engine is changed for each set speed limit with Figure 2 showing one possibility.
12. An element of a control system, where vehicle data can be fed to a remote receiver via a local transmitter.
13. Control systems for vehicles substantially as described in the Description above with reference to Figure 1 and/or Figure 2.