Abstract: A controller for a hydraulic braking system for an aircraft is disclosed. The hydraulic braking system includes a first accumulator and a second accumulator, the controller configured to: receive first signals including first pressure data from a first pressure transducer associated with the first accumulator, receive second signals including second pressure data from a second pressure transducer associated with the second accumulator, monitor the received first and second signals to determine whether a predetermined condition has been met, and issue a warning indicating a loss of integrity of the hydraulic braking system in response to a determination that one or more predetermined conditions has been met. A hydraulic braking system for an aircraft and method to determine the integrity of a hydraulic braking system are also disclosed.

Abstract: A method for adjusting brake pressures on wheel brakes of a motor vehicle includes adjusting, in a normal braking mode as a function of a driver's braking demand determined by a driver of the motor vehicle, the brake pressures on the wheel brakes. The method further includes carrying out, by a brake control unit in a pressure control mode, adjustment of the brake pressures on the wheel brakes to implement at least a drive stability function and/or external braking demands. Furthermore, the method includes determining, by the brake control unit, the brake pressures on the wheel brakes at least when implementing external braking demands while controlling an ideal pressure distribution ratio of the brake pressures at wheel brakes of the front axle to the brake pressures at wheel brakes of a rear axle of the motor vehicle, wherein the control function takes into account a pressure distribution ratio.

Abstract: In a method for estimating the locking pressure in the brake system of a multi-axle vehicle during a dynamic axle-load transfer, the locking pressure is ascertained during the axle-load transfer and the wheel normal force is ascertained at two points in time during the axle-load transfer and the locking pressure is ascertained therefrom at the later point in time.

Abstract: A method for operating an electromechanical brake booster. A pedal force is ascertained, a brake pressure is ascertained from the pedal force by an actuator, and the brake pressure applied to frictional brakes is set, thereby producing a vehicle deceleration. The actuator has a standard configuration wherein, in response to the pedal force, a brake pressure is ascertained that produces a specified standard deceleration of the motor vehicle if a specified disturbance variable has a specified standard value. The influence of the disturbance variable on the vehicle deceleration is compensated. The actuator has at least one control parameter for setting a compensation configuration, an actual value of the disturbance variable is detected, and the compensation configuration is set based on the respective difference between the ascertained actual value and the standard value.

Abstract: A braking system may include a controller, a first wheel and a second wheel. The first wheel may be laterally displaced from the second wheel by a first distance. A first wheel speed sensor may be coupled to the first wheel and a second wheel sensor may be coupled to the second wheel. The controller may be configured to determine at least one of a slip ratio, a coefficient of friction, or a braking pressure of the second wheel in response to failure of the first wheel speed sensor. The controller may be configured to calculate a consistency value of the at least one of the slip ratio, the coefficient of friction, or the braking pressure. The controller may be configured to adjust a braking pressure of the first wheel speed sensor based upon the consistency value and the first distance.

Abstract: A braking system may include a controller, a first wheel and a second wheel. The first wheel may be laterally displaced from the second wheel by a first distance. A first wheel speed sensor may be coupled to the first wheel and a second wheel sensor may be coupled to the second wheel. The controller may be configured to determine at least one of a slip ratio, a coefficient of friction, or a braking pressure of the second wheel in response to failure of the first wheel speed sensor. The controller may be configured to calculate a consistency value of the at least one of the slip ratio, the coefficient of friction, or the braking pressure. The controller may be configured to adjust a braking pressure of the first wheel speed sensor based upon the consistency value and the first distance.

Abstract: A method to limit overheating of a brake equipped with an electromechanically actuable parking brake including the steps of: driving a threaded spindle by an electric motor until a power drain (Imax), corresponding to a brake application force (F), is reached; detection of a travel distance (x0) of the piston corresponding to the brake application force (F) of the brake caliper in a locked state; determination of a second travel distance (x1) by adding a further travel distance value (x11), which corresponds to the desired clearance value, to form (x0); driving of the electric motor until the second travel distance (x1) has been covered by the brake piston; and comparing the vehicle speed with a predefined first speed value, at the upward transgression of which the electric motor is driven once more in the release direction until a further, previously defined travel distance (x12) has been covered.

Abstract: Methods and systems are provided for improving brake performance, including extending the life of carbon brakes on aircraft. One embodiment of the method comprises measuring the speed of the aircraft and the intensity of braking and comparing these to predetermined maximum values for each. If the values are both lower than the maximum values, one or more of the brakes are selectively disabled.

Abstract: A method of reducing wheel slip and wheel locking in an electric traction vehicle includes receiving in a first controller a first signal value representative of a first amount of torque to be applied to at least one wheel of the electric traction vehicle by a motor coupled to the wheel and to the first controller, and a second signal value representative of a reference speed of the electric traction vehicle. The first and second signal values are generated by a second controller in communication with the first controller. The method also includes receiving in the first controller a third signal value representative of a speed of the at least one wheel, determining in the first controller a torque output signal using the first, second, and third signal values; and transmitting the torque output signal from the first controller to the motor.

Abstract: A roll control system (16) for an automotive vehicle (10) is used to actively detect if one of the plurality of the driven wheels (12) is lifted. The system generates a pressure request to determine if the wheel has lifted. By comparing the change in wheel speed of a driven wheel to a change in wheel speed threshold the wheel lift status can be determined. The wheel speed change threshold may be dependent upon various vehicle operating conditions such as powertrain torque, braking torque and/or longitudinal force on the vehicle.

Abstract: A brake control system includes a brake line with a supply line, a pump for supplying brake fluid to the supply line, branch lines branched from the supply line to wheel cylinders, a pressure controller for allowing independent control of brake-fluid pressures within the wheel cylinders, and an ECU for controlling the pump and the pressure controller. The ECU includes an estimate part for estimating the pressures within the wheel cylinders in accordance with a flow amount of brake fluid obtained out of signals indicative of braking conditions, wherein it is estimated an amount of brake fluid flowing from the supply line to the wheel cylinder during execution of brake-fluid pressure control of the ECU and when the control is switched to pressure-increase control for the wheel cylinder having the pressure lower than that in the supply line, and wherein it is estimated the pressure within the wheel cylinder in accordance with the amount of brake fluid as estimated.

Abstract: An arrangement for ensuring the functioning of a brake configuration for a vehicle with a multiplicity of wheels which are arranged on a front axle and at least one rear axle and which support the vehicle. The brake configuration incorporates at least two brake devices, each to act upon one of the wheels, and a brake control with which the brake devices can be activated with a total brake action. A memory stores at least one value of a parameter for the brake devices. The parameter relates to at least one previous braking operation performed by the respective brake device. A control unit distributes the brake action to the brake devices, taking into account the value of the parameter of the respective brake devices when the brake control is actuated. The brake devices are disc brakes.

Abstract: A method and/or a device for estimating pressure and/or volume changes in a hydraulic system having two peripheral volume storage vessels connected to a central volume storage vessel, in which, to increase the response rate, the estimate is based at least at times on a model in which a direct connection to the peripheral volume storage vessels is assumed, regardless of whether or not the peripheral volume storage vessels are simultaneously connected directly to each other.

Abstract: A method is provided for automatically detecting the installation position of brake force generating units of an electromechanical motor vehicle brake system. A steered direction of the motor vehicle during cornering is sensed. Wheel speeds occurring at each wheel of the motor vehicle during the cornering are sensed. The wheel speed occurring for each wheel is compared with a position scheme of setpoint wheel speeds which is representative of the direction of cornering. The actual position of the brake force generating units is determined on the basis of the above comparison.

Abstract: The pressure increases of a hydraulic pressure control module for controlling the braking forces of wheels are decided on the basis of wheel speeds and a vehicle speed estimated from the maximum wheel speed. In this case, on condition that the incremental rate of the vehicle speed exceeds a predetermined threshold value, the vehicle speed exhibited before the incremental rate exceeds the threshold value is kept as an estimated vehicle speed, which is used for deciding the pressure increases. Thus, the pressure increases can be appropriately decided even in a situation where a motor vehicle passes through a very-low-.mu. road part or a drop in road level.

Abstract: A method in part enables a wheel slip control system that controls slip on a per axle basis to control slip on a per truck basis. The wheel slip control system issues on a per axle basis an axle reduction signal indicative of a percentage by which to reduce the braking force that would normally be applied to one wheel/axle combination on a truck of a rail vehicle. The method includes the step of converting the axle reduction signals issued on a per axle basis to a truck reduction priority signal indicative of a percentage by which to reduce the braking force on a per truck basis. For rail vehicles featuring dynamic braking equipment another step involves commanding the dynamic braking equipment to reduce the dynamic braking force being applied to the wheel/axle combinations of the truck in response to the percentage carried by the truck reduction priority signal.

Abstract: The present invention is directed to a vehicle motion control system for maintaining vehicle stability by controlling the braking force applied to at least one wheel of a vehicle. A vehicle condition monitor is provided for monitoring a condition of the vehicle in motion. The braking force is applied by a braking apparatus to each wheel in response to depression of a brake pedal, and on the basis of an output of the monitor and irrespective of depression of the brake pedal. A control variable is provided for actuating the braking apparatus and set in accordance with at least a first parameter (e.g., wheel acceleration) and a second parameter (e.g., slip rate) which are provided on the basis of the output of the monitor, respectively, so that the control variable is varied in response to the output of the monitor. The control variable is integrated during the braking apparatus is actuated.

Abstract: A circuit arrangement for a brake system with electronic brake force distribution control includes circuits which determine the deceleration of the rear wheels and the deceleration of a vehicle or a corresponding reference quantity. The discrepancy of the filtered rear-wheel deceleration from the vehicle deceleration is evaluated for brake force distribution control. To this end, an output signal is produced by way of a differentiator and integrator comparing the rear-wheel deceleration and the vehicle deceleration, and the output signal is evaluated for the control of the braking pressure in the rear-wheel brakes.

Abstract: An anti-skid braking system for wheeled vehicles having fluid actuated brakes associated with the vehicle wheels, has speed sensors associated with the vehicle wheels, a control device responsive to speed signals from the speed sensors to actuate a pressure dump device to periodically release the fluid pressure applied to the brake of any wheel which is determined to be about to lock and to later re-apply the actuating pressure to that brake when the tendency of that wheel to lock has reduced, pulsing of the pressure dump device at intervals during the pressure re-apply phase to cause a repeated interruption to the re-application of pressure to that brake. The pulse timing of the pulsing of the pressure dump device is controlled by the occurrence of wheel angular deceleration being determined to be equal to or in excess of a predetermined threshold value, the magnitude of which is dependent upon events from the previous anti-lock braking cycle.

Abstract: An anti-locking control system is described in which the by electrical interference in the range of the mains frequency of conventional power supplies are detected and eliminated. To that end, in the range of critical speeds, a new reference vehicle speed is formed from the ascertained vehicle speed only if the time intervals between the arriving signal edges of the various rpm sensors are not in the range of the mains frequency.

Abstract: An anti-lock controller is used in an anti-lock control system for detecting a locked condition of a wheel of a vehicle based on wheel rotation speed signal which are pulse signals. The anti-lock controller is provided with a malfunction detector constructed by a soft ware. This malfunction detector includes an interrupt detection function to produce an interrupt signal on receipt of the pulse signal. At the same time, the controller suspends current operations and transfers control thereof to a routine for detecting the locked condition of the wheel. A malfunction determination function is prepared for determining that the anti-lock controller malfunctions when the interrupt signal is absent with a detection of the pulse signal.

Abstract: In an antiskid brake system that increases or decreases a wheel cylinder pressure according to a wheel speed and vehicle speed, an algorithm applied to pressure increase after pressure decrease is improved. A first target pressure increase amount is computed based on the wheel speed and vehicle speed, and a second target pressure increase amount is computed based on a total pressure decrease amount when pressure is decreased. The wheel cylinder pressure is then increased according to the first target pressure increase amount when an elapsed time from the start of pressure decrease to the start of pressure increase, is longer than a predetermined value, and according to the second target pressure increase amount when the elapsed time is shorter than the predetermined value. In this way, increase of slip amount due to excessive pressure increase is prevented.

Abstract: A brake pressure controller, responsive to a wheel speed sensor and coupled to a brake, performs a cyclic control of pressure applied to the brake. A brake pressure cycle includes a pressure apply stage and a pressure dump stage having activation conditions based upon a slip threshold parameter. A predetermined base threshold quantity is modified in dependence upon a measured time duration of the pressure dump stage and/or a slip depth error quantity so that a greater amount of slip is added to the base slip threshold when braking on a deformable surface than when braking on a non-deformable surface.

Abstract: The ABS is provided with a modulator, and when the ABS is activated, control of the caliper pressure by the driver, is modified by the operation of the modulator having the aforementioned inlet valve (normally closed to a pressurized fluid source) and aforementioned outlet valve (normally open to a fluid exit), both controlled by the above-described control logic circuit. The modulator increases or decreases the caliper pressure, in response to changes in the pressurized fluid, regulated by such valves. Depending on the operation of the control logic circuit described above, three events may occur. When the inlet and outlet valves are not operated (i.e. their normal state), the modulator releases pressurized fluid through the output valve, and increases caliper pressure, to increase braking up to a predetermined maximum. If only the outlet valve is operated (i.e. both the inlet and outlet valves are closed), the modulator remains in a constant state and likewise, the caliper pressure is kept constant.

Abstract: An ABS skid detection protection system for a wheeled vehicle detects a predetermined level of deceleration at a wheel; detects, memorizers and holds for a prescribed period the wheel speed value at that predetermined deceleration level; detects whether the angular acceleration of the monitored wheel first falls below and then re-establishes the predetermined deceleration level within the prescribed level; and corrects the memorizsed value of wheel speed by subtracting from it an amount equal to the vehicle deceleration multiplied by either the elapsed time since the wheel speed value was memorized or the elapsed time since the initiation of a short-duration pulse by which the actuating pressure applied to a brake can be temporarily dumped upon detection of the predetermined level of deceleration of the wheel.

Abstract: Improvements in vehicle antilock braking systems of the type having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The improved system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration. This comparison normally invokes the enhanced anti-skid braking mode.

Abstract: Improvements in vehicle antilock braking systems of the type having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The improved system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration. This comparison normally invokes the enhanced anti-skid braking mode.

Abstract: An antiskid control device which calculates an estimated fluid pressure of each of wheel cylinders under antiskid control in each control cycle so as to adjust a fluid pressure of each of the wheel cylinders on the basis of the estimated fluid pressure and behaviors of the wheels. The device includes a differential pressure detecting member which detects a difference between a fluid pressure of a master cylinder and the fluid pressure of each of the wheel cylinders so as to produce an output signal indicative of the difference between the fluid pressure of the master cylinder and the fluid pressure of each of the wheel cylinders. When the difference between the fluid pressure of the master cylinder and the fluid pressure of each of the wheel cylinders is found to be in the vicinity of zero, the estimated fluid pressure of each of the wheel cylinders is set to a predetermined value by stopping addition in calculation of the estimated fluid pressure.

Abstract: An anti-skid braking system for wheeled vehicles having fluid actuated brakes associated with the vehicle wheels, speed sensors associated with the vehicle wheels and a cyclically operating control device which is responsive to speed signals from the speed sensors to actuate a pressure dump device to periodically release the fluid pressure applied to the brake of any wheel which is determined to be about to lock and to later re-apply the actuating pressure to that brake when the tendency of that wheel to lock has reduced, and wherein the pressure dump phase is arranged to be cancelled during wheel-lock when the aggregate dump time for the current cycle exceeds a limit value based upon a weighted-average dump time of previous cycles.

Abstract: A frictional value between a motor vehicle tire and a road surface is determined for use in an ABS system or a traction control system. Various sensors at the automobile ascertain the vehicle speed and the brake pressure at individual wheels. The angular acceleration of the wheel is calculated from the angular velocity thereof. A wheel slip is calculated from the vehicle speed and from the angular acceleration. The dependency of the coefficient of friction is approximated from the wheel slip with a non-linear approximation equation. The current estimation value for the coefficient of friction is estimated with a recursive estimation algorithm from measurement values previously ascertained during a preceding measuring instant.

Abstract: Vehicle antilock braking systems having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration.

Abstract: A method of wear-dependent braking force distribution prevents adhesion problems without being limited to lowest brake pressures as is the case with conventional methods. Wear control is dispensed with only in the case of operationally very rare braking actions, for example, those above 0.3 g or a learned adhesion threshold. These rare braking actions are limited, in practice, to genuinely critical braking situations. Otherwise, the control interventions are carried out with to produce balanced wear only in the long term; an attempt is made to achieve wear at the same rate rather than simply balanced wear.