Abstract: An speed reducer assembly is provided along with a method and apparatus for adjusting the speed reducer assembly to achieve zero backlash. The speed reducer assembly includes a split worm with a fixed worm segment and a floating worm segment which mesh with the teeth of the gear. The position of the worm relative to the gear can be precisely and accurately adjusted without disassembly of the speed reducer or removal of the speed reducer assembly from the housing. Elimination of a constant spring force on the floating worm segment of the split worm also provides for the elimination of drag which results in a speed reducer assembly with increased efficiency. The elimination of drag also reduces the wear on the elements of the speed reducer assembly.

Abstract: A method and system for controlling an anti-lock brake system cycle rate in a vehicle wherein the cycle includes a primary apply stage and a secondary apply stage in which increasing pressure is applied to the brake. The primary and secondary stages are separated by a hold stage in which a substantially constant pressure is applied to the brake for a time interval which varies as a function of the estimated average vehicle deceleration.

Abstract: A non-volatile RAM stores a selectable trim indicator which, in turn, is used to select one of a plurality tables of trim constant data from read-only memory. The selected table of trim constant data is loaded into working memory of a microprocessor-based control unit to thereby calibrate control logic of an automotive ABS for the vehicle in which the control unit is mounted.

Abstract: A reduced brake switch dependence (RBSD) control method and system for a vehicle anti-lock brake system (ABS) having a brake switch. The control method includes generating a RBSD control signal when the brake switch is inoperative, and performing RBSD control of the ABS in response to the RBSD control signal. The control system includes wheel speed sensors, ABS control valves, and a programmable microprocessor ABS control unit for performing the control method.

Abstract: The method and system for controllably restricting the on time of a pump of an electro-hydraulic control system for a hydraulic brake system by modeling the amount of hydraulic brake fluid in a low pressure accumulator (LPA) of the hydraulic brake system. Sensors sense wheel speed of their respective wheels of a vehicle. Control valves, including isolation and dump valves, together with the pump, vary the amount of brake fluid in the LPA. A control unit electrically coupled to the pump, the control valves and the wheel speed sensors, initially detects an electro-hydraulic control event based on the sensed wheel speeds and then activates the control valves and pump which vary the amount of brake fluid in the LPA. The control unit models the amount of brake fluid in the LPA during the activation and controls the state of the pump based on the modeled amount of brake fluid in the LPA.

Abstract: Method and system for testing components, such as a motor, of a vehicular system capable of controlling the relative slip between a vehicle wheel and a road surface, for functionality prior to performing antilock functions utilizing a progressively increasing energization duty cycle, so as to minimize perception of noise by the vehicle operator by minimizing motor energization duration and minimizing peak motor rotational speed. The method includes energizing the motor successively with a plurality of electrical signals, each electrical signal being applied to the motor for a predetermined period of time and having at least one pulse having a width which is progressively increased with respect to the width of the at least one pulse of the previous electrical signal. Each pulse has a width sufficiently long to permit motor operation to test functionality and yet sufficiently short so that the noise associated with the operating motor during this test is minimized.

Abstract: A vehicle braking system such as an anti-lock brake system and/or a traction control utilizes a separate solenoid-actuated, two position, three-way valve in each controlled channel of the brake system for controlling the application of pressure to the respective wheel brake circuit. The valve includes a first port connected to the controlled wheel brake(s), a second port connected to an outlet of a hydraulic pump, and a third port connected to the inlet of the hydraulic pump. The valve is only moveable between a first position wherein the outlet of the pump is connected to the wheel brake to increase pressure to the wheel brake, and a second position wherein the wheel brake is connected to the inlet of the pump to decrease pressure to the wheel brake. An electronic control is provided for operating the valve to control the application of pressure to the selected wheel brakes.