Abstract:
In steering control for individually controlling wheel steering angles null1, null2, null3, and null4 of a vehicle in accordance with a condition equation for forming a prescribed mode, one of the condition equation variables is used as a steering command value S. In a process for changing the command value S from a value S1 to a value S2, for transitioning the steering angles null1, null2, null3, null4 from values nullnull1, null2, null3, null4nullS1 corresponding to the steering command value S1, to values nullnull1, null2, null3, null4nullS2 corresponding to the steering command value S2, the steering angles null1, null2, null3, null4 are changed toward incremental transition steering angles nullnull1, null2, null3, null4nullS1nullnullS corresponding to a steering command value (S1nullnullS), which is the steering command value S1 to which an incremental steering command value nullS has been added. After the steering angles null1, null2, null3, null4 reach their incremental transition steering angles and steering angle conformance is detected, the angles are changed toward incremental transition steering angles nullnull1, null2, null3, null4nullS1nullnnullS corresponding to a steering command value (S1nullnnullS), which is the steering command value to which an incremental steering command value nullS has been added nulln timesnull in succession. nullThis is repeated as many times as requirednull to change the steering angles null1, null2, null3, null4 from nullnull1, null2, null3, null4nullS1 to nullnull1, null2, null3, null4nullS2.
Abstract:
An electric vehicle steering/drive control method and apparatus having predetermined steering modes defining composite patterns of individual wheel travel paths, whereby the vehicle wheels are controlled independently. The steering modes are determined by different condition equations related to each composite pattern. A steering mode select signal is generated based on a mode selection by a vehicle driver. The steering mode select signal is received by a wheel steering angle computer and a wheel rotation speed computer. Based in part on the steering mode select signal, the wheel steering angle computer generates a signal that is received by a steering motor controller, which in turn controls motors that change the steering angle of the wheels. An actual angle sensor generates a signal based on the actual angle of the wheels and a steering angle comparator receives the actual angle sensor signal. In addition, to move the vehicle in a particular direction and at a particular speed, a speed and direction command signal is also generated based on driver input. This speed and direction command signal is received by a common signal rate of change suppression computer, which generates a signal received by the wheel steering angle computer and a wheel rotation speed computer. Then the wheel rotation speed computer generates a signal based on signals received from the common signal rate of change suppression computer and the steering angle comparator computer. A drive motor controller receives the wheel rotation speed signal and activates drive motors associated with each wheel, thereby causing the wheels to move rotationally.