Abstract: A brake fluid pressure control apparatus of a vehicle includes a hydraulic brake in which the fluid pressure of a brake cylinder for a wheel is controlled so as to retard the rotation of the wheel, and a hydraulic actuator capable of controlling the fluid pressure of the brake cylinder. An actuator controller feedback-controls the hydraulic actuator so that the actual fluid pressure of the brake cylinder approaches a target fluid pressure determined in accordance with a braking requirement. The actuator controller determines a control gain used when determining a control command value to be sent to the hydraulic actuator, based on at least one of the temperature of a working fluid and a slipping state of the wheel.

Abstract: An operation-characteristic obtaining apparatus including an operation-characteristic obtaining portion which obtains, as an operation characteristic of an electromagnetic control valve which includes a coil and which is opened and closed according to at least a relationship between (a) an acting force corresponding to a difference of respective pressures of a working liquid on either side of the electromagnetic control valve and (b) an electromagnetic drive force corresponding to an electric current supplied to the coil, a relationship between (c) a valve switching current as an electric current that is supplied to the coil of the electromagnetic control valve at a time when the electromagnetic control valve is switched between a closed state thereof and an opened state thereof and (d) a difference at the time of the respective pressures on either side of the electromagnetic control valve; and a leakage detecting portion which detects, when the operation-characteristic obtaining portion obtains the operation

Abstract: A non-consideration creating portion creates a non-consideration control command value based on a target value and an actual value of hydraulic pressure of a brake cylinder in a control-target brake system i. A consideration creating portion creates a consideration control command value based on the target value and the actual value of the hydraulic pressure in the control-target brake system i and a target value and an actual value of hydraulic pressure in a comparison-target brake system j. Then, one of the consideration control command value and the non-consideration command value is selected based on an absolute value of a difference in the target value between the control-target brake system i and the comparison-target brake system j, and a combination of a control mode in the control-target brake system i and a control mode in the comparison-target brake system j.

Abstract: A tire air-pressure abnormality alarming device for informing decrease in air-pressure of tires attached to a four-wheeled vehicle, characterized in that the device prohibits start of initializing operations for updating stored values for physical amounts related to tires or wheels in the case where air-pressures of the tires are judged to be normal, if air-pressure abnormality of a tire is being alarmed. Initialization is accepted only after the internal pressure has become normal, whereby erroneous initialization with any tire being in a decompressed condition can be prevented. Thus, normal operations for detecting decompression of a tire can be maintained.