Patent ID: 8066338

Claim:
A vehicle brake controller that controls a vehicle brake apparatus, the vehicle brake apparatus braking a wheel that moves on a road surface, the vehicle brake apparatus comprising: a line for brake fluid; a wheel cylinder arranged in the line in correspondence with the wheel, the wheel cylinder applying a braking force to the wheel in correspondence with a brake fluid pressure produced based on braking operation by the driver; a reservoir provided in the line, the reservoir retaining the brake fluid flowing out from the wheel cylinder, a direction heading from the wheel cylinder to the reservoir being referred to as a flow direction of the brake fluid; a pump that sucks the brake fluid retained in the reservoir, the pump discharging the sucked brake fluid to a portion of the line that is upstream from the wheel cylinder with respect to the flow direction; and an on-off valve arranged in the line at a position between the wheel cylinder and the reservoir, wherein the brake controller controls the pump and the on-off valve in such a manner as to repeat a cycle of increase and decrease of a retaining amount of the brake fluid in the reservoir, wherein the brake controller includes: a reference suction amount setting section that sets a reference suction amount of the pump, wherein the greater a μ value of the road surface is, the greater the reference suction amount the reference suction amount setting section sets; an average retaining amount estimating section that estimates an average retaining amount, which is a time average of the retaining amount, wherein, each time a prescribed cycle ends, the average retaining amount estimating section estimates the average retaining amount in the current prescribed cycle on the assumption that the pump has sucked a constant amount of brake fluid in the current prescribed cycle; a deviation correction amount setting section that sets a deviation correction amount in accordance with which a deviation of the average retaining amount is corrected, the deviation correction amount setting section calculating the deviation between the average retaining amount at the end of the previous prescribed cycle and the average retaining amount at the end of the current prescribed cycle, wherein the greater the deviation is, the greater the deviation correction amount the deviation correction amount setting section sets; and a control section that performs a deviation pump control on the pump, wherein, while performing the deviation pump control, the control section sets a target suction amount of the pump based on the reference suction amount and the deviation correction amount, and controls the pump in such a manner that the pump sucks the brake fluid by the amount corresponding to the target suction amount.