Steering control unit
AssigneeJtekt Corporation
InventorShingo Maeda
Life of this patent
Estimating the term…
Abstract
When a steering angle reaches a first value close to a second value that defines a boundary of the maximum physical range of operation of a steering wheel, an ECU calculates a virtual end controlled variable that sharply increases a steering torque. The ECU calculates a second limit on the virtual end controlled variable and calculates a final limit (upper and lower limits) on an assist controlled variable by taking into account the second limit. When performing virtual end control, the ECU calculates the final limit on the assist controlled variable by using, as a first limit corresponding to the steering torque, a previous value held by upper and lower limit holders, instead of a present value calculated in accordance with the steering torque in a present calculation cycle.
Claims6
A steering control unit comprising;
- an assist controller that calculates an assist controlled variable on the basis of a plurality of kinds of state quantities including a steering torque and a steering angle, the assist controlled variable being used to control power supply to a motor that generates an assist force to be supplied to a steering mechanism of a vehicle;
- a correction controller that performs, when the steering angle reaches a first value close to a second value that defines a boundary of a physical range of operation of a steering wheel that is included in the steering mechanism, correction control that calculates a correction quantity that corrects the assist controlled variable to sharply increase the steering torque;
- a limit calculator that sets first limits individually for each of the plurality of kinds of state quantities, each of the first limits being used to limit a variation range of the assist controlled variable in accordance with a corresponding one of the plurality of kinds of state quantities, the limit calculator being configured to calculate a final limit on the assist controlled variable by adding together all the first limits;
- and
- a limit processor that limits the variation range of the assist controlled variable on the basis of the final limit calculated by the limit calculator, wherein
- the limit calculator sets a second limit that limits the correction quantity in accordance with the steering angle, and calculates the final limit by taking into account the second limit, and when the correction control is performed, the limit calculator calculates the final limit by using the first limit that corresponds to the steering torque immediately before the correction control is performed.
Dependencies are inferred from the claim text.