Abstract: Instantaneous coefficient of friction .mu.(K) and slope K.sub..mu. of the .mu.-slip curve are evaluated from the drive torque or the brake torque and the wheel speeds. The values of K.sub..mu. obtained by successive calculations constitute the feedback of the control system, which is compared with a target value K.sub..mu.tar. The connection value thus obtained influences a final control element which modifies the braking pressure or, for example, the quantity of fuel per unit time. The control system gain varies with the adhesion coefficient .mu.(K).

Abstract: Torque proportioning between the front and rear wheels of a vehicle is achieved by controlling the speed of each rear wheel, via modulation of the hydraulic brake pressure of the rear wheel during braking, to be the same as the speed of the front wheel on the same side of the vehicle.

Abstract: A vehicle brake has a fixed backplate carrying a pair of friction elements and an actuator operable to urge the elements into braking engagement with a rotary braking surface. An abutment for the elements has a portion which is deflectable by load on the elements arising from braking torque. A radiation input device directs radiation at a surface of the deflectable portion and a device is provided to sense radiation after its impingement on the portion and to transmit the sensed radiation to a device producing a responsive electrical output representing deflections of the portion.

Abstract: A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

Abstract: A wheel lock control system in which when an incipient wheel lockup condition is first sensed, the brake pressure at that time is used to estimate a brake pressure value that is substantially equal to but greater than the brake pressure required to produce an incipient wheel lockup condition. The brake pressure is then dumped to allow wheel speed recovery. Following wheel speed recovery, the estimated brake pressure is applied to the wheel brake. At the same time, the brake torque tending to accelerate the wheel is computed by an expression taking into consideration the rate of change in wheel speed as the brake pressure is reapplied. When a peak brake torque value is identified, the optimum brake pressure that will result in the identified peak brake force is determined from the same expression used to calculate the brake torque but with the term associated with the rate of change in wheel speed being eliminated.

Abstract: A system for controlling the torque developed by a fluid actuated brake as it slows an aircraft wheel. In one embodiment, the system includes a strain gauge (62) for sensing the load applied to a brake metering valve (16). In another embodiment, the pressure of the hydraulic fluid output from the brake metering valve is sensed by a pressure transducer (42). Depending upon the sensor used, the system is operative to control the pressure applied to a brake assembly (54) of an aircraft as a function of the mechanical load or pressure. The system includes a torque control (50,120) connected to control one or more valves (22, or 83 and 102), modulating the pressure of hydraulic fluid applied to the brake assembly; the valves may be part of an antiskid control system. A torque sensor (46) is disposed on a torque reaction arm (36) and produces a signal indicative of the torque developed by the brake assembly.

Abstract: An anti-skid control system for a vehicle with at least one wheel. The anti-skid control system includes a wheel sensor for sensing a rotational speed of the wheel and for generating a signal indicative of the sensed wheel speed and a brake sensor for sensing a braking force of a braking device which brakes the wheel and for generating a signal indicative of the sensed braking force. The wheel sensor and the brake sensor are respectively coupled to a control unit for receiving the wheel speed signal and the braking force signal to control the braking force of the braking device to a target braking force so that a slip ratio of the wheel assumes a predetermined value. The control unit determines the target braking force at the time of start of the anti-skid control to be equal to a braking force corresponding to the resultant of torques developed in the wheel at the control start time.

Abstract: A wheel lock control system is described for a wheel braking system that includes a motor driven actuator for applying controlled hydraulic brake pressure to the wheel brake that is determined by motor current. The motor current corresponding to the brake pressure producing the maximum possible braking effort during each brake pressure application is identified and a value related thereto is reapplied to the motor after an incipient wheel lockup condition is sensed.

Abstract: An apparatus which measures and regulates the braking torque of a brake unit in long-term operational use. The brake unit includes both a brakable element and the braking device. An output signal from at least one temperature-dependent measuring element, located on or in one of the brakable elements and the braking device, is supplied to an evaluation apparatus. The evaluation apparatus determines, from the current value of the output signal of the temperature-measuring element, a present braking torque, and adjusts such torque when desirable.

Abstract: A proportioning valve assembly (10) in a housing (12) is pressure responsive to control the flow of fluid to a wheel brake. A proportioning valve (20) is disposed within a chamber (26) having an inlet (33) and outlet (114), the inlet (33) receiving pressure from a pressure generator such as a master cylinder. A poppet (80) of the proportioning valve (20) is connected by a shaft (90) with a plunger (100) disposed within another chamber (30), the other chamber (30) being isolated from fluid pressure in the chamber (26) housing the proportioning valve. A fluid-containing chamber (13) contains an inertia sensing mass (40) which engages a valve mechanism (34) that controls fluid communication between the fluid-containing chamber (13) and other chamber (30). A friction element (120) of the wheel brake engages a braking torque responsive valve (140) which communicates fluid pressure to a chamber (30a).

Abstract: A vehicle braking control system is provided for sensing (76) the magnitude of the vehicle operator's demand for braking effort and for distributing the braking effort between the individually controllable vehicle (22) brake sites to achieve balanced braking (12) if relatively low braking effort demand (0% to A%) is sensed and to achieve proportional braking (14) if relatively high braking effort demand (B% to 100%) is sensed.

Abstract: A motor vehicle comprises two driven axles (5, 8), which are interconnected by an interaxle coupling (10) for transmitting a torque only when the halves of the coupling (10) rotate at different speeds and by a speed-changing transmission (9) connected in series with the coupling (10). A brake system (12 to 15) is provided for braking the wheels of both axles (5, 8). In order to ensure that the wheels of the driven rear axle (8) will not block before the wheels of the driven front axle (5), a pressure-setting controller (17) is adapted to control a brake pressure regulator (16) associated with the driven rear axle (8) and is responsive to a reversal of the direction in which torque is transmitted to and from the driven rear axle (8).

Abstract: A disc brake caliper is mounted with a rollpin or similar sleeve secured between the brake torque transmitting member and the brake torque receiving member. The rollpin sleeve is also positioned about the brake hose applying braking pressure to the caliper assembly so that when brake actuation occurs the caliper brake torque reaction compresses the rollpin, closing the brake hose passage completely when the maximum permissible braking torque is exerted. Thus the brake actuating pressure and the resulting braking effort are limited so that the wheel does not reach incipient wheel lock at maximum allowable braking effort on dry pavement.

Abstract: In a vehicular brake system such as for use in a commercial aircraft, a torque limiter for maintaining the torque supplied by the braked wheels below a predetermined maximum value. The torque limiter includes a plurality of torque pistons which sense the torque of the wheels and operate in response to a torque value greater than the desired value to isolate the metered brake fluid within the brake cylinders and subsequently reduce the pressure of the brake fluid within the brake cylinders to release the brakes and decrease torque. The torque pistons are mounted in a piston carrier and extend from the piston carrier to engage notches formed in a torque arm housing that at least partially surrounds the piston carrier. Torque piston movement is initiated by relative rotational movement between the piston carrier and torque arm housing caused by an excessive reaction torque from the vehicle structure to the torque produced by the brakes.

Abstract: A booster unit for moving a vehicle on a slope and having a booster and a master cylinder coupled to the booster, comprising a brake fluid pressure holding valve having an actuator and provided at a brake fluid pressure piping system for either maintaining or releasing the brake fluid pressure in accordance with the conditions of the vehicle on a slope, a plurality of sensors for detecting the vehicle conditions and a control unit including a microprocessor having a CPU, a RAM, and a ROM so as to receive detected signals from the sensors and to calculate and produce control signals to the actuator of the brake fluid pressure holding valve in accordance with the conditions of the vehicle on a slope, and a method of controlling the booster unit. With this construction, a smooth moving of the vehicle can be realized on a slope.

Abstract: A hydraulic brake system for automotive vehicles with at least one load sensor (41) sensing the load condition of the vehicle and with at least one sensor (14, 15, 21, 22) associated wtih each vehicle axle for the detection of a braking parameter decisive for the braking operation. The measured values sensed are supplied to an electric evaluation circuit (18) which during a braking operation permanently computes suitable braking pressure values for the wheel brakes (3, 4) of the rear axle and delivers corresponding control signals to a braking pressure modulator (31, 53, 54). A braking force sensor (14, 15, 21, 22) is associated with at least one vehicle wheel (12, 13, 19, 20) of each vehicle axle.

Abstract: A torque sensing braking controller senses directly the braking torque exerted by a rotating element (14, 114, 214, 314) upon at least one friction element (20, 222, 320 and 332) of the brake (10, 210, 310), such that the sudden decrease in torque which occurs when wheel lock-up and skidding occurs is sensed and results in the communication of an increased output pressure to oppose outward displacement of at least one differential area piston (40 and 50, 240 and 250, 340) by fluid pressure received from the master cylinder, the increased output pressure causing the piston to reduce braking force exerted by the friction element against the rotating element (14, 114, 214, 314) so that the rotating element may recommence rotation. The torque sensing braking controller may be utilized in drum brake (10), duo-servo drum brake (210), and disc brake (310) assemblies.

Abstract: A vehicle anti-skid braking system, particularly for motor cycles, which employs a pilot brake for the purpose of generating operating power for the anti-skid system. The pilot brake is mounted for limited movement so that torque reaction moves it to actuate, for example, a fluid pressure pump. Such a pump actuated by the pilot brake may be used to control application, release and re-application of a main brake or may act only to return to a master cylinder fluid released from the main brake during an anti-skid operation.

Abstract: A vehicle wheel anti-skid apparatus is provided which senses and measures the torque applied to a vehicle wheel, by the road, when the brakes are applied. It uses the wheel torque to power and control the brake thereby limiting the brake friction torque so that it cannot exceed the friction torque capacity of the wheel-road contact, thus maintaining maximum friction coefficients between the wheel and the road and prevent skidding and loss of control of the vehicle.

Abstract: A controlled wheel braking system for vehicles wherein fluid pressure on the wheel brake cylinder is relieved at the moment of wheel lock up so as to prohibit skidding and at the same time optimize the braking of the vehicle. The system includes a control valve positioned in the brake fluid line between the master cylinder and the wheel brake cylinder which is responsive to imminent wheel lock up. The control valve senses wheel lock up and upon sensing bleeds brake fluid from the wheel brake cylinder to unlock the wheel thereby preventing skidding. Upon sensing the unlocking of the wheel the bled brake fluid is again fed to the wheel brake cylinder to optimize the braking of the vehicle. If the wheel again locks up the cycle is repeated thereby providing a pumping action on the brakes.

Abstract: An airplane braking system includes a torque control circuit for control torque developed in a braked landing wheel. The torque control circuit is responsive to a torque signal from a transducer located in the torque equalizing links of the landing gear assembly. The torque signal is compared with a reference signal and passed through an integrator, a differentiator and proportional gain amplifier in the torque control circuit to provide a torque control signal. The torque control signal is applied to a brake pressure relief valve to reduce brake pressure. The torque control circuit is advantageously integrated with an antiskid circuit responsive to wheel speed to thereby preventskidding as well as excessive torque conditions.

Abstract: A controlled wheel braking system for vehicles wherein fluid pressure on the wheel brake cylinder is relieved at the moment of wheel lock up so as to prohibit skidding and at the same time optimize the braking of the vehicle. The system includes a control valve positioned in the brake fluid line between the master cylinder and the wheel brake cylinder which is responsive to imminent wheel lock up. The control valve senses wheel lock up and upon sensing bleeds brake fluid from the wheel brake cylinder thereby preventing skidding.

Abstract: In an aircraft multiple disc brake assembly, an excessive total brake torque can be experienced during favorable, dry, conditions. To limit the brake torque to a predetermined maximum, the plurality of conventional brake piston assemblies are modified to provide a pressure responsive surface area which is in an opposing relationship to the braking force. When a predetermined amount of braking torque is experienced, conventional electronics employing strain gauge sensors control a solenoid valve to vent pressurized brake fluid to the opposing surface area thereby reducing the braking force and limiting the total braking torque experienced by the brake assembly to a predetermined maximum amount. The brake pressure is not affected by this system.

Abstract: The present invention relates to a method and device for controlling a hydraulic disc brake, particularly for heavy-transport aircraft, wherein the functioning of the brake is servo-controlled so that the braking torque which it exerts follows the variations of a predetermined reference torque.

Abstract: A wheel lock control system is described for a wheel braking system that includes a motor driven actuator for applying controlled hydraulic brake pressure to the wheel brake that is determined by motor current. The motor current corresponding to the brake pressure producing the maximum possible braking effort during each brake pressure application is identified and a value related thereto is reapplied to the motor after an incipient wheel lockup condition is sensed.