GB2119326A - Vehicle steering systems - Google Patents
Vehicle steering systems Download PDFInfo
- Publication number
- GB2119326A GB2119326A GB08208717A GB8208717A GB2119326A GB 2119326 A GB2119326 A GB 2119326A GB 08208717 A GB08208717 A GB 08208717A GB 8208717 A GB8208717 A GB 8208717A GB 2119326 A GB2119326 A GB 2119326A
- Authority
- GB
- United Kingdom
- Prior art keywords
- steering
- valve
- servo motor
- input
- steering system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
- B62D5/30—Safety devices, e.g. alternate emergency power supply or transmission means to ensure steering upon failure of the primary steering means
Abstract
A vehicle steering system 10 comprises steering gear 12, input means 14 of the steering gear connected to a driver's steering wheel 16, output means 18 of the steering gear connected to steerable ground wheels 20 of the vehicle, and a servo motor 22 connected to the steering gear 12 to provide power assistance. An input sensor 24 associated with input means 14 monitors the steering input (e.g. steering torque) to the steering gear, and an output sensor 26 associated with servo motor 22 monitors operation (e.g. servo pressure) of the servo motor. A micro-processor 28 is connected to both the input and output sensors to compare their responses and is operable to generate a safety response signal (e.g. an audible or visual warning) when the relationship between their responses falls outside predetermined limits. The micro-processor can receive inputs from sensors sensing vehicle load/height, vehicle speed, vehicle acceleration, wind forces or temperature. <IMAGE>
Description
SPECIFICATION
Vehicle steering systems
This invention relates to vehicle steering systems and some aspects of the invention relate to safety features of power-assisted steering systems, while other aspects of the invention relate to the provision of steering systems responsive to one or more of a series of parameters relating to vehicle operation and operating conditions, whereby a degree of sophistication in the response of the steering system can be achieved.
In relation to the safety aspects of the invention, the problem in question is that of enabling a driver of a vehicle having a power assisted steering system easily to control the vehicle even in the event of a malfunction of the power assistance system. Of course, road vehicles are always provided with mechanical steering gear whereby the driver can exert a manual effort to control the steering of his vehicle under all conditions. However, the problem arises that where power assistance is provided, it can happen that in the event of a malfunction of the control system a large force is applied to the steering gear in opposition to the driver's manual efforts, and this clearly has significant safety implications.
An object of this aspect of the invention is to provide a vehicle steering system incorporating means for mitigating or overcoming the safety problems identified above.
According to the invention there is provided a vehicle steering system comprising:
steering gear;
input means of said steering gear and connectible to a control device such as a driver's steering wheel;
a servo motor connected to said steering gear to provide power assistance;
characterised by;
an input sensor associated with said input means and arranged to monitor the steering input to said steering gear;
an output sensor associated with said servo motor to monitor operation of said servo motor; and
comparator means connected to both of said sensors to compare the responses of said sensors and operable to generate a safety response signal when the relationship between said responses falls outside predetermined limits.
Said input sensor may be arranged to control the operation of the servo motor. The input sensor may comprise a strain gauge mounted on a steering input member such as a steering column, forming part of the input means.
The comparator means may comprise a microprocessor arranged to control the servo motor. At least one additional sensor may be provided to monitor another vehicle operating parameter and connected to the micro-processor whereby the performance of the vehicle steering system is modulated by said other parameter.
Although the invention is particularly applicable to power-assisted steering systems having nonmechanically actuated power assistance control valves, nevertheless the invention is also applicable to systems of the kind in which the control valve is directly mechanically actuated by, for example, a valve actuating mechanism built into the input section of the steering gear.
According to another aspect of the invention there is provided a vehicle steering system comprising:
steering gear having input means connectible to a control device such as a driver's steering wheel;
output means connectible to steerable ground wheels;
a fluid pressure operated servo motor connected to the steering gear to provide power assistance and controlled by an electrically operated control valve; and
an input sensor associated with said input means to monitor the input to said steering gear and connected to said electrically operated control valve whereby the valve controls the servo motor in accordance with the steering input;
characterised in that said control valve has positioning means independent of the electrical operation thereof and operative to move a valve member of the control valve towards a position in which the servo motor is de-activated or partially de-activated.
In an embodiment described below, the provision of positioning means for the control valve as defined above enhances the safety aspects of the performance of the steering system by reducing the likelihood of opposition by the servo motor to a driver's steering input, in the event of a system malfunction.
A further aspect of the invention relates to the provision of a vehicle steering system having improved response to vehicle operation and operating conditions.
According to this aspect of the invention there is provided a vehicle steering system comprising:
steering gear having an input member connectible to a control device such as a driver's steering wheel;
an input sensor connected to said input member;
a micro-processor connected to said input sensor;
a rotary or linear spool valve arranged for electrical operation and controlled by said micro-processor; and
a servo motor connected to said steering gear to provide power assistance and controlled by said spool valve.
In an embodiment described below the vehicle steering system is responsive to inputs from a series of sensors monitoring a wide variety of operating parameters, whereby the steering system adapts itself to the conditions the vehicle is encountering at any given time. The use of a micro-processor for this purpose enables a degree of sophistication and responsiveness hitherto unattainable in vehicle steering systems.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:
Figure 1 shows a diagrammatic scheme of a rack and pinion vehicle steering system with a powerassist hydraulic ram controlled by a spool valve and an associated electrical control circuit; and
Figure 2 shows a modification of the system of
Figure 1 by the addition of a pair of valves providing hydraulic flow control; and
Figure 3 shows a further modification in which a cut-off valve is provided on the suction side of the hydraulic pump; and
Figure 4 shows a further alternative arrangement in which a by-pass valve is provided on the pressure side of the pump; and
Figure 5 shows an alternative by-pass arrangement and an electrically-operated pump with pump switch-off facilities; and
Figures 6to 9 show sections through the main control valve of the system of Figure 1 iliustrating valve structure, spool-centring and spool edge features.
As shown in Figure 1, a vehicle steering system 10 comprises steering gear 12, input means 14 of the steering gear connected to a control device 16 in the form of a driver's steering wheel, output means 18 of the steering gear connected to steerable ground wheels 20 of the vehicle, and a servo motor 22 connected to the steering gear 12 to provide power assistance. An input sensor 24 associated with input means 14 monitors the steering input to the steering gear, and an output sensor 26 associated with servo motor 22 monitors operation of the servo motor.
Comparator means 28 is connected to both the input and output sensors to compare the responses of the sensors and is operable to generate a safety response signal when the relationship between their responses fails outside predetermined limits.
Steering gear 12 comprises a conventional rack and pinion system connected to steerable wheels 20 by track rods 30,32. Input means 14 is in the form of a conventional steering column on which steering wheel 16 is mounted. The output means 18 of the steering gear is formed by track rods 30, 32.
Servo motor 22 is in the form of a double-acting hydraulic ram directly connected to the steering gear track rods.
Input sensor 24 is in the form of a strain gauge mounted directly on steering column 14. Output sensor 26 comprises a hydraulic pressure sensor connected in the pressure supply lines 34, 36 to ram 22. The ram is operated by a hydraulic system comprising a pump 38 drawing fluid from a reservoir 40 and delivering fluid through a control valve 42 operated by a solenoid 44. Comparator means 28 is in the form of a micro-processor having electrical input lines not only from output sensor 26 but also from the bridge circuit of strain gauge 24 and from a vehicle speed sensor 46, a vehicle load or height sensor 48 and an acceleration sensor 50. Microprocessor 28 controls solenoid 44 through a power interface or control device 52. As indicated, pump 38 may be driven by an electric motor 54 or by a belt 56 from the vehicle engine.
Steering gear 12 provides the usual manual control of the steerable wheels. Strain gauge 24 monitors the driver's steering input to the steering gear and micro-processor 28 actuates the spool 58 of control valve 42 in accordance with the direction and
magnitude of the steering input sensed.
Micro-processor 28 likewise monitors the responses of sensors 46,48 and 50 so as to adjust the actuation of valve 42 in accordance with vehicle speed, vehicle loading and the dynamic status of the vehicle. Further sensors may be provided to monitor, for example, wind forces acting on the vehicle.
The response of output sensor 26 monitoring the hydraulic pressure supplied to ram 22 provides micro-processor 28 with a measure of the thrust applied to the steering gear by the ram. The micro-processor compares this signal with the steering input signal obtained from strain gauge 24 to ensure that the relationship between the two falls within predetermined limits which have been programmed into the micro-processor. In the event that the relationship falls outside the predetermined limits a safety response signal is generated by the micro-processor as more fully described below. One example of such a safety response signal is an audible or visual warning to the driver of the vehicle.
Such a signal would be generated in the event of control valve 42 becoming jammed in a position in which ram 22 is pressurised. Means is described below for automatically de-activating the ram in this situation.
The embodiment of Figure 2 is otherwise constructed in a manner similar to that of the Figure 1 embodiment, but is provided with a flow control valve 60 and a variable restrictor valve 62 on the upstream side of control valve 42.
Flow control valve 60 comprises a spool 64 biased by a spring 66. The output of valve 60 passes to restrictor valve 62 and hence to control valve 42.
Conduits 68,70 connect the spool end chambers of valve 60 to the upstream and downstream sides of restrictor valve 62.
Restrictor valve 62 itself comprises a tapering needle member 72 actuated by a solenoid 74 and an associated return spring 76.
In use, the pressure applied to opposite ends of spool 64 depends on the restriction offered by needle member 72 whereby the spool 64 maintains a constant flow of fluid to control valve 42 in accordance with the setting of needle member 72. Control of needle member 72 is provided by micro-processor 28 through an additional power interface 78 through which solenoid 74 is operated.
The flow control system provided by valves 60,62 enables micro-processor 28 to varythe rate of response of the steering system in accordance with the parameters monitored by the sensors described above in connection with Figure 1.
In the event of the generation of a safety response signal by the micro-processor in the manner described above, this signal is arranged to cause solenoid 74 to severely restrict the flow of fluid to ram 22 if not to cut off such flow altogether.
The embodiment of Figure 3 is otherwise constructed substantially the same as the embodiment of Figure 1, but is provided with a cut-off valve 80 on the suction side of pump 38 to cut off the hydraulic supply to the pump when a safety response signal is generated by micro-processor 28.
Cut-off valve 80 is a spool valve operated by a solenoid 82 controlled by the micro-processor in the same way as the solenoids described above.
In use, micro-processor 28 can completely cut off the hydraulic supply to the power assistance ram when the responses of pressure sensor 26 and the strain gauge on the steering column indicate a malfunction in the power assistance system.
In the embodiment of Figure 4, which likewise is similar to the Figure 1 embodiment, there is provided in place of the suction side valve 80 a pressure side return valve 84 connected between pump 38 and main control valve 46. The spool 86 of valve 84 is biased by a spring 88 to a fluid return position, and the spool is normally actuated by a solenoid 90 connected to micro-processor 28 in the same way as the other solenoids described above. The operation of the system is similar to that of Figure 3 but the use of a pressure side control valve avoids the pump being starved, and starvation is damaging to certain types of pump.
In the embodiment of Figure 5, which is otherwise similar to that of Figure 4, there is provided an electric motor 92 to drive pump 38 and the motor is controlled by micro-processor 28. When the microprocessor generates a safety response signal, motor 92 is switched off thereby de-pressurising the hydraulic system whereby the servo motor 22 is deactivated.
In Figure 5 a return valve 94 similar to return valve 84 is provided, but the spool return spring 96 is arranged externally.
Figures 6 to 9 show suitable constructions of the main control valve 42 described above.
In Figure 6, valve 42 has an inlet port 100, and with the spool 102 in its indicated neutral position, fluid passes around the spool's control edges and back to reservoir 40 via outlet port 104.
Spool 102 operated by a rod 106 from solenoid 44 to connect inlet port 100 to two pressure supply ports (not shown) connected to pressure supply lines 34, 36 for ram 22.
The control valve 42 shown in Figure 7 is provided, in addition, with positioning means independent of the external operation of the valve and operative to move the valve member of the valve towards a position in which the servo motor 22 is de-activated or partially de-activated. The positioning means comprises a double-acting coiled control spring 108 connected to the valve spool 110 which acts to return the spool to its open-centre fluid return position shown.
In addition to spring 108, spool 110 is formed with a drilling 112 connecting inlet port 100 to a reaction chamber 114 in which return spring 108 is housed. In this way a return thrust is applied to spool 110 by the pressure fluid whereby the tendency of the spool to jam during use is reduced.
In the embodiment of Figure 8, the arrangement is otherwise similar to that of Figure 7, but a pressure limiting valve 116 is provided in association with the drilling 112 in the valve spool. Valve 116 comprises a ball 118 and an associated spring 120 whereby the pressure return function exerted on the main spool of valve 42 only comes into effect when a certain pre-set pressure has been exceeded.
Figure 9 shows modification of the configuration of the edges of the spool valve so as to provide more progressive and less rapid pressure changes in response to small spool movements when opening and closing the valve.
The principal advantages of the embodiments described above relate to safety aspects of the steering system. The provision of means to monitor the steering input from the vehicle driver and the power assistance applied to the steering gear by the servo motor enables malfunctions arising from a variety of causes to be overcome. Where there is an electrical power failure, the control valve spool is returned by spring or fluid pressure means to its fluid return position. Likewise, if the control valve tends to stick or jam the provision of fluid pressure return means or spring return means ensures the application of a significant return force to the valve member. In any case where the output from the servo motor is detected as being not in accordance with the driver's steering input, the servo motor is deactivated in any of a variety of ways disclosed.
Moreover, the system disclosed above is applicable to all types of vehicle steering system including purely manual systems with a minimum of cost and modification.
Moreover, the system disclosed enables a sophisticated steering response to be obtained by virtue of the use of a variety of vehicle and operating condition sensors, the responses of which are monitored by a micro-procressor which is programmed to adapt the performance of the system accordingly.
Many modifications to the system described will be apparent to those skilled in the art. Of course the rack and pinion steering gear and the double acting ram could be interchanged with other steering gear and alternative power assist systems. Any suitable form of control valve may be employed including open and closed centre systems and rotary or linear spools. Alternative or additional vehicle and operating parameters may be sensed and an example of an additional sensor is a temperature sensor. Alternatives to the valve centring arrangements of Figures 7 and 8 will be apparent to those skilled in the art.
Likewise, the steering input and output sensors may be arranged and placed elsewhere. For example, the output sensor could be in the form of a strain gauge placed on any suitable mechanical output compo nentofthe steering gear.
As an alternative to the strain gauges described above for use as either or both of the input and output sensors, a torque transducer may be employed to monitor torque or strain applied, for example to the steering column of the vehicle. This non-contact magnetic field-based sensor has advantages over the use of strain gauges, particularly for use as the input sensor.
Moreover, the "servo motor" of the present invention, though usually in the form of a hydraulic ram may alternatively be in the form of any other suitable force or thrust-generating device capable of providing the necessary power assistance.
Claims (21)
1. A vehicle steering system comprising:
steering gear;
input means of said steering gear and connectible to a control device such as a driver's steering wheel;
a servo motor connected to said steering gear to provide power assistance;
characterised by;
an input sensor associated with said input means and arranged to monitor the steering input to said steering gear;
an output sensor associated with said servo motor to monitor operation of said servo motor; and
comparator means connected to both of said sensors to compare the responses of said sensors and operable to generate a safety response signal when the relationship between said responses falls outside predetermined limits.
2. Avehicle steering system according to claim 1 characterised in that a signal derived from said input sensor is arranged to control the operation of said servo motor.
3. Avehicle steering system according to claim 2 characterised in that said input sensor comprises a strain gauge or torque transducer associated with a steering input member such as a steering column forming part of said input means.
4. A vehicle steering system according to any one of the preceding claims characterised in that said servo motor comprises a fluid pressure operated thrust device, and said output sensor comprises a pressure sensor connected to a fluid pressure supply line for said thrust device.
5. Vehicle steering gear according to any one of the preceding claims characterised in that said safety
response signal is arranged to operate a safety device to de-activate or partially de-activate said servo monitor.
6. A vehicle steering system according to claim 5 characterised in that said servo motor comprises a fluid pressure operated thrust device and an associated pump and control valve, said safety device comprising an additional valve to de-activate or
partially de-activate the servo motor.
7. Avehicle steering system according to claim 6 characterised in that said additional valve comprises
a changeover valve having a valve member movable to a safety position in which the valve cuts off the
suction side of said pump from an associated fluid
reservoir.
8. Avehicle steering system according to claim 6
characterised in that said additional valve is in the form of a change-overvalve having a valve member
movable to a position in which the valve diverts the fluid pressure supply from said pump and main
control valve to a fluid reservoir.
9. A vehicle steering system according to claim 7
or claim 8 characterised in that said valve member is
spring biased towards its safety position.
10. Avehicle steering system according to any
one of claims 6 to 9 characterised in that said pump
is electrically operated and said safety response
signal is arranged to operate a cut-out switch to
de-activate the pump.
11. A vehicle steering system according to any
one of claims 6 to 10 characterised in that said main
control valve comprises a valve member spring
biased to a position in which the pressure chambers
of said servo motor are connected to a fluid reser
voir.
12. Avehicle steering system according to any one of claims 6 to 10 characterised in that said main control valve comprises a relief valve which on opening causes the valve member of said control valve to be fluid-pressure biased towards a position in which said servo motor is disconnected from said fluid pressure supply pump.
13. Avehicle steering system according to any one of the preceding claims characterised in that said comparator means comprises a microprocessor arranged to control said servo motor.
14. Avehiclesteering system according to claim 13 characterised by the provision of at least one additional sensor to monitor another vehicle operating parameter and connected to said microprocessor whereby the performance of the vehicle steering system is modulated by said other parameter.
15. Avehicle steering system substantially as described herein with reference to the accompanying drawings.
16. A vehicle steering system comprising:
steering gear having input means connectible to a control device such as a driver's steering wheel;
output means connectible to steerable ground wheels;
a fluid pressure operated servo motor connected to the steering gearto provide power assistance and controlled by an electrically operated control valve; and
an input sensor associated with said input means to monitor the input to said steering gear and connected to said electrically operated control valve whereby the valve controls the servo motor in accordance with the steering input;
characterised in that said control valve has positioning means independent of the electrical operation thereof and operative to move a valve member of the control valve towards a position in which the servo motor is de-activated or partially de-activated.
17. A vehicle steering system according to claim 16 characterised in that said positioning means comprises resilient means acting on said valve member.
18. Avehicle steering system according to claim 16 characterised in that said positioning means cmprises a relief valve openable to provide pressure positioning of said valve member.
19. A vehicle steering system comprising:
steering gear having an input member connectible to a control device such as a driver's steering wheel;
an input sensor connected to said input member;
a micro-processor connected to said input sensor;
a rotary or linear spool valve arranged for electrical operation and controlled by said micro-processor;
and
a servo motor connected to said steering gear to
provide power assistance and controlled by said spool valve.
20. A vehicle steering system according to claim
19 characterised by at least one additional sensor to
monitor a vehicle operating parameter and con
nected to said micro-processorto modulate the steering response on the system accordingiy.
21. A vehicle steering system according to claim 19 or claim 20 characterised by an electrically operated fluid flow control valve arranged to be controlled by said micro-processor and to control the flow of fluid to said servo motor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08208717A GB2119326B (en) | 1982-03-25 | 1982-03-25 | Vehicle steering systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08208717A GB2119326B (en) | 1982-03-25 | 1982-03-25 | Vehicle steering systems |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2119326A true GB2119326A (en) | 1983-11-16 |
| GB2119326B GB2119326B (en) | 1985-11-27 |
Family
ID=10529258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08208717A Expired GB2119326B (en) | 1982-03-25 | 1982-03-25 | Vehicle steering systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2119326B (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2130537A (en) * | 1982-10-05 | 1984-06-06 | Aisin Seiki | Power assisted steering arrangements |
| EP0164842A2 (en) * | 1984-05-05 | 1985-12-18 | Trw Cam Gears Limited | Power assistance steering systems for vehicles |
| US4584488A (en) * | 1984-11-13 | 1986-04-22 | Allied Corporation | Controller for generating a pair of mutually exclusive pulse train signals |
| US4828062A (en) * | 1986-09-29 | 1989-05-09 | Honda Giken Kogyo Kabushiki Kaisha | Motor-operated power steering apparatus for vehicle with steerable front and rear wheels |
| US4842090A (en) * | 1986-04-23 | 1989-06-27 | Honda Giken Kogyo Kabushiki Kaisha | Electrically power-assisted four-wheel steering system for vehicles |
| EP0361699A2 (en) * | 1988-09-28 | 1990-04-04 | Trw Cam Gears Limited | A power assisted vehicle steering system |
| EP0407716A1 (en) * | 1989-07-08 | 1991-01-16 | Daimler-Benz Aktiengesellschaft | Method of adjusting the assisting force in a power steering in accordance with various operating condition parameters |
| CN115214773A (en) * | 2022-03-01 | 2022-10-21 | 广州汽车集团股份有限公司 | Vehicle control method, device, system, vehicle and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB849328A (en) * | 1959-06-16 | 1960-09-28 | Gen Motors Corp | Improved road vehicle steering system |
| GB1424937A (en) * | 1973-03-05 | 1976-02-11 | Nissan Motor | Automotive steering system process for the production of bis-halogen carbonyl anilines |
| GB2050974A (en) * | 1979-04-19 | 1981-01-14 | Still Gmbh | A steering device for a vehicle comprising hydraulic power-assisted steering facilities |
| GB2069429A (en) * | 1980-02-20 | 1981-08-26 | Bosch Gmbh Robert | A hydraulic steering apparatus |
-
1982
- 1982-03-25 GB GB08208717A patent/GB2119326B/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB849328A (en) * | 1959-06-16 | 1960-09-28 | Gen Motors Corp | Improved road vehicle steering system |
| GB1424937A (en) * | 1973-03-05 | 1976-02-11 | Nissan Motor | Automotive steering system process for the production of bis-halogen carbonyl anilines |
| GB2050974A (en) * | 1979-04-19 | 1981-01-14 | Still Gmbh | A steering device for a vehicle comprising hydraulic power-assisted steering facilities |
| GB2069429A (en) * | 1980-02-20 | 1981-08-26 | Bosch Gmbh Robert | A hydraulic steering apparatus |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2130537A (en) * | 1982-10-05 | 1984-06-06 | Aisin Seiki | Power assisted steering arrangements |
| EP0164842A2 (en) * | 1984-05-05 | 1985-12-18 | Trw Cam Gears Limited | Power assistance steering systems for vehicles |
| EP0164842A3 (en) * | 1984-05-05 | 1987-04-01 | Trw Cam Gears Limited | Power assistance steering systems for vehicles |
| US4584488A (en) * | 1984-11-13 | 1986-04-22 | Allied Corporation | Controller for generating a pair of mutually exclusive pulse train signals |
| US4842090A (en) * | 1986-04-23 | 1989-06-27 | Honda Giken Kogyo Kabushiki Kaisha | Electrically power-assisted four-wheel steering system for vehicles |
| US4828062A (en) * | 1986-09-29 | 1989-05-09 | Honda Giken Kogyo Kabushiki Kaisha | Motor-operated power steering apparatus for vehicle with steerable front and rear wheels |
| EP0361699A2 (en) * | 1988-09-28 | 1990-04-04 | Trw Cam Gears Limited | A power assisted vehicle steering system |
| EP0361699A3 (en) * | 1988-09-28 | 1990-10-03 | Trw Cam Gears Limited | A power assisted vehicle steering system |
| EP0407716A1 (en) * | 1989-07-08 | 1991-01-16 | Daimler-Benz Aktiengesellschaft | Method of adjusting the assisting force in a power steering in accordance with various operating condition parameters |
| DE3922527A1 (en) * | 1989-07-08 | 1991-01-17 | Daimler Benz Ag | METHOD FOR SETTING A SUPPORTING FORCE IN A POWER STEERING DEPENDING ON SEVERAL DRIVING CONDITION PARAMETERS |
| CN115214773A (en) * | 2022-03-01 | 2022-10-21 | 广州汽车集团股份有限公司 | Vehicle control method, device, system, vehicle and storage medium |
| CN115214773B (en) * | 2022-03-01 | 2023-11-21 | 广州汽车集团股份有限公司 | Vehicle control method, device, system, vehicle and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2119326B (en) | 1985-11-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19930325 |