VEHICLE STEERING-BASED SPEED CONTROL SYSTEM AND METHOD
First Claim
2-1. The control system of claim 1, wherein:
- the electronically controlled transmission supplies torque to the driven wheels through an electronically controlled differential lock unit;
an electronically controlled front wheel drive control unit is actuatable to transmit torque from the transmission to steerable front wheels; and
the ECU generating a front wheel drive command as a function of the wheel angle signal, generating a diff lock command as a function of the wheel angle signal, and transmitting to the ECU the selected speed limit, the front wheel drive command and the diff lock command, the ECU, in response to the selected speed limit, the front wheel drive command and the diff lock command, controlling engagement of the front wheel drive unit, controlling the differential lock unit, and controlling the transmission.
1 Assignment
0 Petitions
Accused Products
Abstract
A control system and method is provided for a vehicle. The control system includes a speed sensor, a wheel angle sensor, and a vehicle position sensor. An electronic control unit (ECU) determines a yaw-rate error as a function of at least the vehicle position signal, determines a first speed limit as a function of the yaw-rate error, determines a second speed limit as a function of a vehicle lateral acceleration, and determines a third speed limit as a function of the wheel angle signal. The ECU selects the lowest of the first, second and third speed limits, generates a front wheel drive command and a diff lock command as a function of the wheel angle signal. The ECU also limits the vehicle speed to not greater than the selected lowest wheel speed limit.
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Citations
19 Claims
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2-1. The control system of claim 1, wherein:
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the electronically controlled transmission supplies torque to the driven wheels through an electronically controlled differential lock unit; an electronically controlled front wheel drive control unit is actuatable to transmit torque from the transmission to steerable front wheels; and the ECU generating a front wheel drive command as a function of the wheel angle signal, generating a diff lock command as a function of the wheel angle signal, and transmitting to the ECU the selected speed limit, the front wheel drive command and the diff lock command, the ECU, in response to the selected speed limit, the front wheel drive command and the diff lock command, controlling engagement of the front wheel drive unit, controlling the differential lock unit, and controlling the transmission.
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5. A control system for a vehicle having an engine supplying torque to a transmission which supplies torque to driven wheels through an electronically controlled differential lock unit, an electronically controlled front wheel drive control unit which is actuatable to transmit torque from the transmission to steerable front wheels, and an electronic control unit (ECU), the control system comprising:
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a speed sensor which transmits a vehicle speed signal to the ECU; a wheel angle sensor which transmits a wheel angle signal which represents an angle of the steered wheels to the ECU; a vehicle position sensor generating a vehicle position signal; the ECU determining a yaw-rate error as a function of at least the vehicle position signal, determining a first speed limit as a function of the yaw-rate error, determining a second speed limit as a function of a vehicle lateral acceleration, determining a third speed limit as a function of the wheel angle signal, selecting the lowest of the first, second and third speed limits, generating a front wheel drive command as a function of the wheel angle signal, generating a diff lock command as a function of the wheel angle signal, and, in response to the selected speed limit, the front wheel drive command and the diff lock command, controlling engagement of the front wheel drive unit, controlling the differential lock unit, and controlling the transmission so that the vehicle speed is not greater than the selected lowest wheel speed limit. - View Dependent Claims (6, 7, 8, 9)
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10. A method of controlling a vehicle having an engine supplying torque to a transmission which supplies torque to driven wheels, and an electronic control unit (ECU) for controlling the transmission, the method comprising:
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sensing vehicle speed and generating a vehicle speed signal; sensing a steered wheel angle and generating a wheel angle signal; sensing a vehicle position and generating a vehicle position signal; determining a yaw-rate error as a function of at least the vehicle position signal; determining a first speed limit as a function of the yaw-rate error; determining a second speed limit as a function of a vehicle lateral acceleration; determining a third speed limit as a function of the wheel angle signal; selecting a lowest of the first, second and third speed limits; and in response to the selected speed limit, controlling the transmission so that the vehicle speed is not greater than the selected lowest wheel speed limit. - View Dependent Claims (11, 12)
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13. A method of controlling a vehicle having an engine supplying torque to a transmission which supplies torque to driven wheels through an electronically controlled differential lock unit, an electronically controlled front wheel drive control unit which is actuatable to transmit torque from the transmission to steerable front wheels, and a transmission electronic control unit (ECU) for controlling the transmission, the method comprising:
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determining a yaw-rate error as a function of sensed parameters; determining a first speed limit as a function of the yaw-rate error; determining at least a second speed limit as a function of a vehicle lateral acceleration; selecting the lowest of at least the first and second speed limits; and in response to the selected speed limit, controlling the transmission so that the vehicle speed is not greater than the selected lowest wheel speed limit.
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14. A control system for a vehicle having a propulsion system supplying torque to driven wheels through an electronically controlled differential lock unit, an electronically controlled front wheel drive control unit which is actuatable to transmit torque to steerable front wheels, and an electronic control unit (ECU), the control system comprising:
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a speed sensor connected to the ECU and generating a vehicle speed signal; a wheel angle sensor connected to the ECU and generating a wheel angle signal which represents an angle of the steered wheels; a vehicle position sensor connected to the ECU and generating a vehicle position signal; the ECU determining a yaw-rate error as a function of at least the vehicle position signal, determining a first speed limit as a function of the yaw-rate error, determining a second speed limit as a function of a vehicle lateral acceleration, determining a third speed limit as a function of the wheel angle signal, selecting the lowest of the first, second and third speed limits, generating a front wheel drive command as a function of the wheel angle signal, generating a diff lock command as a function of the wheel angle signal, the ECU, in response to the selected speed limit, the front wheel drive command and the diff lock command, controlling engagement of the front wheel drive unit, controlling the differential lock unit, and controlling the transmission so that the vehicle speed is not greater than the selected lowest wheel speed limit. - View Dependent Claims (15, 16)
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17. A control system for a vehicle having an engine supplying torque to a an electronically controlled transmission which supplies torque to driven wheels, and an electronic control unit (ECU), the control system comprising:
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a speed sensor generating a vehicle speed signal; a wheel angle sensor generating a wheel angle signal which represents an angle of the steered wheels; and a vehicle position sensor generating a vehicle position signal, the ECU determining an expected yaw-rate as a function of the wheel angle signal and the vehicle speed signal, the ECU determining a yaw-rate error as a function of a difference between the vehicle position signal and the expected yaw-rate, determining a speed limit as a function of the yaw-rate error, and in response to the speed limit, controlling the transmission so that the vehicle speed is not greater than the speed limit.
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18. A control system for a vehicle having an engine supplying torque to a an electronically controlled transmission which supplies torque to driven wheels, and an electronic control unit (ECU), the control system comprising:
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a speed sensor generating a vehicle speed signal; and a vehicle position sensor generating a vehicle position signal, the ECU determining a speed limit as a function of a vehicle lateral acceleration, and in response to the speed limit, controlling the transmission so that the vehicle speed is not greater than the wheel speed limit.
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19. A control system for a vehicle having an engine supplying torque to a an electronically controlled transmission which supplies torque to driven wheels, and an electronic control unit (ECU), the control system comprising:
a wheel angle sensor generating a wheel angle signal which represents an angle of the steered wheels, the ECU determining a speed limit as a function of the wheel angle signal and in response to the speed limit, controlling the transmission so that the vehicle speed is not greater than the speed limit.
Specification