EP0137491A2
Expired / Lapsed
EP
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Fail safe steering effort control system
Assignee: Nissan Motor Co Ltd
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Filing: 1984-10-10
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Granted: —
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Expires: 2004-10-10
Abstract
Abstract An actuator (7) for varying the degree of power assistance is connected with a main battery (8) through a fuse (12) separate from a fuse (13) which protects a controller (2) such as a microcomputer for controlling the steering effort in accordance with the vehicle speed and other variables. An emergency control means (14,2) is connected with the actuator for preventing the steering from becoming abnormally heavy or light when the controller is isolated from the main battery. The emergency control means keeps the steering moderate by using a backup battery (14) or by limiting a current supplied to the actuator to a predetermined value.
Inventors
- 👤 Yasuhiro Shiraishi
- 👤 Makoto Miyoshi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 20:18
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/0481; B62D5/0484
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
193 words
A fail safe steering effort control system for a vehicle power steering, comprising means (3,4) for sensing at least one variable of a condition of the vehicle, an actuator (7) for varying a steering effort, main control means (2), connected with said sensing means (3,4), for regulating said actuator by sending a control signal to control the steering effort in accordance with the variable, a main battery (8) connected with said main control means (2) through fuse means (10), characterized by a first power circuit connecting said main battery (8) with said main control means (2) and a second power circuit connecting said main battery (8) with said actuator (7), a first fuse (13) inserted in said first power circuit, a second fuse (12) inserted in said second power circuit so that said actuator (7) can be supplied with power from said main battery (8) even when said first fuse opens said first power circuit, and emergency control means (14,2), connected with said actuator (7), for providing said actuator with an emergency control signal to control the steering effort in a predetermined manner when the supply of power to said controller is stopped.
Claim 2
Dependent Claim
193 words
A fail safe steering effort control system for a vehicle power steering, comprising means (3,4) for sensing at least one variable of a condition of the vehicle, an actuator (7) for varying a steering effort, main control means (2), connected with said sensing means (3,4), for regulating said actuator by sending a control signal to control the steering effort in accordance with the variable, a main battery (8) connected with said main control means (2) through fuse means (10), characterized by a first power circuit connecting said main battery (8) with said main control means (2) and a second power circuit connecting said main battery (8) with said actuator (7), a first fuse (13) inserted in said first power circuit, a second fuse (12) inserted in said second power circuit so that said actuator (7) can be supplied with power from said main battery (8) even when said first fuse opens said first power circuit, and emergency control means (14,2), connected with said actuator (7), for providing said actuator with an emergency control signal to control the steering effort in a predetermined manner when the supply of power to said controller is stopped.
Claim 3
Dependent Claim
106 words
A system according to claim 1, characterized in that said emergency control means (14,2) is connected with said first power circuit, and so arranged that said emergency control means is in a normal state to allow the normal operation of said main control means (2) when said main control means is supplied with power from said main battery (8) through said first power circuit, and in an emergency state to provide said actuator (7) with the emergency control signal when said first fuse (13) opens said first power circuit but said actuator (7) is supplied with power from said main battery (8) through said second.power circuit.
Claim 4
Dependent Claim
39 words
A system according to claim 2, characterized in that said emergency control means (14,2) maintains the steering effort at a constant value intermediate between upper and lower limits between which said main control means normally controls the steering effort.
Claim 5
Dependent Claim
25 words
A system according to claim 3, characterized in that the constant value is approximately equal to the mean value of the upper and lower limits.
Claim 6
Dependent Claim
36 words
A system according to claim 3, characterized in that said sensing means comprises a vehicle speed sensor (3) and said main control means (2) controls the steering effort in accordance with the speed of the vehicle.
Claim 7
Dependent Claim
58 words
A system according to claim 5, characterized in that said sensing means further comprises a steering angle sensor (4) for sensing an angular displacement of a steering wheel of the vehicle, and said main control means (2) controls the steering effort in accordance with not only the vehicle speed but also the angular velocity of the steering wheel.
Claim 8
Dependent Claim
53 words
A system according to claim 1, characterized in that said emergency control means comprises a backup battery (14) connected with said main control means (2) for supplying power to said main control means when said main control means is not supplied with power from said main battery (8) through said first power circuit.
Claim 9
Dependent Claim
57 words
A system according to claim 7, characterized in that said emergency control means comprises means for holding the control signal inputted to said actuator (7) at a predetermined constant value when said first fuse (13) opens said first power circuit but said actuator is supplied with power from said main battery (8) through said second power circuit.
Claim 10
Dependent Claim
26 words
A system according to claim 8, characterized in that said main control means (2) and said holding means of said emergency control means comprise a microcomputer.
Claim 11
Dependent Claim
46 words
A system according to claim 9, characterized in that said backup battery (14) is connected with said main battery (8) through said first power circuit so that said backup battery can be charged when said first power circuit is closed by said first fuse (13) .
Claim 12
Dependent Claim
17 words
A system according to claim 10, characterized in that said backup battery (14) is a nickel-cadmium battery.
Claim 13
Dependent Claim
52 words
A system according to claim 1, characterized in that said emergency control means is connected with said main battery (8) through said second power circuit so that said emergency control means (15, 16) can be supplied with power from said main battery even when said first fuse opens said first power circuit.
Claim 14
Dependent Claim
89 words
A system according to claim 11, characterized in that said emergency control means is connected with said main battery (8) through said first power circuit, and so arranged that said emergency control means (15,16) is in a normal state to allow the normal operation.of said main control means (2) when said main control means is supplied with power from said main battery (8) through said first power circuit, and in an emergency state to provide the emergency control signal when said first fuse (13) opens said first power circuit.
Claim 15
Dependent Claim
48 words
A system according to claim 13, characterized in that said main control-means .(2) regulates said actuator (7) by regulating a current for driving said actuator (7), and wherein said emergency control means (15,16) fixes the current for driving said actuator at a constant value in the emergency state.
Claim 16
Dependent Claim
90 words
A system according to claim 14, characterized in that said emergency control means (2) comprises a current determining resistor (16) so connected with said actuator that said current determining resistor determines the value of the current supplied by said main battery (8) to said actuator (7) for driving said actuator, switching means (15b) connected in series with said current determining resistor, and operating means (15a) connected with said first power circuit for holding said switching means in an open state when said emergency control means is in the normal state.
Claim 17
Dependent Claim
39 words
A system according to claim 15, characterized in that said main battery (8), said second fuse (12), said actuator (7), said switching means (15b) and said current determining resistor (16) are connected in series to form a series circuit.
Claim 18
Dependent Claim
27 words
A system according to claim 16, characterized in that said switching means_(15b) comprises a normally closed relay contact, and said operating means comprises a relay coil (15a).
Claim 19
Dependent Claim
100 words
A system according to claim 16, characterized in that said operating means comprises a first transistor (17) which is in an on state when said main control means (2) is supplied with power from said main battery (8) through said first fuse (13), and in an off state when said main control means is not supplied with power through said first fuse, and said switching means comprises a second transistor (18) which is in an off state when said first transistor is in the on state, and in an on state when said first transistor is in the off state.
References Cited (Backward Citations)
No citation records indexed.
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