2686 results about "Brake torque" patented technology

Strategies other than immediate elimination of regenerative braking (FIG. 2) are invoked when an incipient wheel lock-up is detected, the ABS becomes active, and/or incipient wheel slip is detected. The strategies include: reducing the regenerative braking torque as a function of the coefficient of friction of a surface on which the vehicle is traveling (FIG. 3); and adjusting regenerative braking in relation to the rate at which wheel slip is changing (FIG. 4). Some of the strategies may be applied on an individual wheel basis (FIG. 5), and some of the strategies may be applied in conjunction with operating friction brakes of the vehicle to apply at least some of the reduction in regenerative braking torque as friction brake torque (FIG. 1).

A hybrid vehicle is capable of performing regenerative operations of generator-motors disposed adjacently to front wheels and/or rear wheels of the vehicle so as to achieve efficient conversion of kinetic energy of the vehicle into electric energy as much as possible when the vehicle slows down, thereby permitting higher use efficiency of energy. When the vehicle decelerates, a target deceleration force or a target deceleration torque of the vehicle is set, and a permissible maximum value of the braking torque to be imparted to rear wheels from a second generator-motor is set, and the permissible maximum value and the target deceleration torque of the vehicle, whichever is smaller, is set as a target braking torque to be imparted from the second generator-motor to the rear wheels. Furthermore, with the remaining torque of the target deceleration torque being set as an upper limit, a target braking torque to be imparted to front wheels from a first generator-motor is determined, and a friction type braking mechanism compensates a shortfall torque of a total sum of the target braking torques of the two generator-motors to reach the target deceleration torque.

Requested brake torque and requested throttle torque are assigned opposite algebraic signs in both rollback and non-rollback states. In the non-rollback state, requested motor torque development includes a process step (206) in which requested brake torque and requested throttle torque are algebraically summed. In the rollback state, requested motor torque development includes a process step (218) in which requested throttle torque is substituted for the regeneration torque limit. In the rollback state, the difference between the requested throttle torque and the requested brake torque is compared with a zero vehicle speed regeneration torque limit (228) when the result of comparing the difference between requested throttle torque and the requested brake torque with the regeneration torque limit (222) discloses that the latter difference does not exceed the regeneration torque limit. The result is used to determine respective amounts of motor torque and friction brake torque (230, 232, 234, 236).

A vehicle powertrain comprises an internal combustion engine 10 and an electric motor 14 capable of producing driving or braking torque for the vehicle. The exhaust system for the engine 10 includes a catalytic converter 22. A control unit 18 monitors the temperature of the catalytic converter 22 using a sensor 32 and controls the driving or braking torque produced by the electric motor 14 so that the load on the engine produces exhaust gases of a suitable temperature to keep the catalytic converter within its optimum operating temperature range while maintaining the desired total output of torque from the powertrain.

A method for reducing or mitigating the effects of vibration in a vehicle brake system, particularly those that can lead to brake groan or other unwanted noise. According to an exemplary embodiment, when the vehicle brake system detects certain vibratory conditions, it makes slight braking adjustments (e.g., adjustments to fluid pressure, brake force, brake torque, etc.) that are aimed to address the brake groan. The vehicle brake system can then determine the effectiveness of the braking adjustments and, if need be, make additional braking adjustments. The method is particularly well suited for use with brake-by-wire systems, but can be used with a number of different vehicle braking systems.

An anti-lock braking system includes a friction torque gradient estimating unit for estimating, from a small number of parameters, the gradient of friction torque with respect to a slip speed, and controls a braking force acting on wheels on the basis of the friction torque gradient estimated by the friction torque gradient estimating unit. The friction torque gradient estimating unit may employ several types of estimating methods; e.g., a method of estimating the gradient of friction torque from only time-series data concerning a wheel speed; a method of estimating the friction torque gradient from time-series data concerning wheel deceleration as well as from braking torque or time-series data concerning physical quantities associated with the braking torque; or a method of estimating the friction torque gradient from micro-gains which are obtained when brake pressure is excited in a very small amount at the resonance frequency of a vibration system comprising a vehicle, wheels, and a road surface and which represent the characteristics of the vibration system. Further, there is also disclosed a method of determining, from the thus-estimated friction torque gradient, the limit of the characteristics of friction torque developed between the wheels and the road surface.

A torque control strategy control for management of regenerative braking in a motor vehicle. A first processor (12) processes throttle request data (20) and torque modification data (40) from a second processor (14) to develop motor torque request data (28) for controlling rotary electric machine torque. The second processor processes brake request data (26), the throttle request data, and operating data from the at least one operating data source to develop friction brake torque data (30) for controlling friction brake torque applied to the vehicle and the torque modification data for the first processor. The two processors interact such that as long as the operating data from the at least one operating data source does not require that regenerative braking torque be limited, the torque modification data supplied to the first processor from the second processor equates to the brake torque request data, and the friction brake torque data does not cause the friction brakes to be applied, and when the operating data from the at least one operating data source calls for some limiting of the regenerative braking torque, the amount of limiting is subtracted from the torque modification data and the friction brake torque data equates to that amount of limiting for causing the friction brakes to be applied in that amount.

The invention discloses a tandem regenerative brake control method. The method comprises the following steps of monitoring the intend of a driver and the state of a vehicle by a vehicle control unit VMS, and judging whether to enter a regenerative brake control mode or not; under a regenerative brake control mode, comprehensively considering the states of a battery and a motor by the vehicle control unit VMS, calculating the currently allowable maximal regenerative brake torque, and transmitting the maximal regenerative brake torque to a brake control unit (BCU); and monitoring the brake requirement of the driver by the brake control unit (BCU), in the range allowed by the vehicle control unit VMS, balancing the regenerative brake torque and the conventional hydraulic brake torque, and on the premise of meeting the brake requirement of the driver, preferentially feeding back the regenerative brake torque to optimally reclaim brake energy. The method can be widely applied to the field of regenerative brake control.

A method for operating at least an intake and exhaust valve in a cylinder with a piston of an engine in a vehicle, comprising during conditions of an engine shut-down, maintaining at least one of the intake and exhaust valves in a closed position, and during conditions where said at least one valve is in said closed position operating with the other of the intake and exhaust valve open, then closing the other of the intake and exhaust valve, and then opening the other of the intake and exhaust valve to generate braking torque to slow the engine.

Improved methods and systems for controlling hydraulically or electrically actuated anti-lock brake systems (ABS) on air and land vehicles requiring only measurement of wheel angular speed although brake torque measurements can also be employed if available. A sliding mode observer (SMO) based estimate of net or different wheel torque (road/tire torque minus applied brake torque) derived from the measured wheel speed is compared to a threshold differential wheel torque derived as a function of a “skid signal” also based on wheel speed only to generate a braking control signal. The braking control signal can be employed to rapidly and fully applying and releasing the brakes in a binary on-off manner and, as an additional option, possibly modulating the maximum available brake hydraulic pressure or electrical current when the brakes are in the “on” state in a continuous manner. In the case of the basic on-off component of braking, the brakes are released when the estimate of differential wheel torque is less than the threshold differential wheel torque (i.e. for relatively high values of brake torque), and the brakes are applied fully when the estimate of differential wheel torque is greater than or equal to the threshold differential wheel torque. For aircraft landing gear applications, a fore-aft accelerometer mounted on the landing gear can be used to suppress nonlinear gear displacement oscillations commonly called gear walk in the direction of wheel roll.

The hybrid electric all-wheel-drive (HEAWD) system comprises a heat engine, a transmission, an integrated starter/alternator (ISA), a motor control module (MCM), a traction motor (TM), and a battery pack. The engine drives either the front wheels or the rear wheels, and TM drives the other pair of wheels. ISA starts and assists the engine or generates electricity. Both ISA and TM apply braking torque on the wheels and regenerate the vehicle kinetic energy into electricity during deceleration. MCM provides electric current to and controls both ISA and TM to work in their desired working modes. The battery stores the electric energy generated by the motors and provides electric power to the motors. A double-rotor traction motor provides the functions of a conventional traction motor plus an axle differential/torque coupling device.

Method and systems are provided for controlling a vehicle system including an engine that is selectively deactivated during engine idle-stop conditions. One example method comprises, adjusting a brake torque applied to a deactivated rotating engine after an engine restart request, the brake torque applied to slow the engine to at least a predetermined threshold speed without stopping the engine, and engaging a starter to the still rotating engine to increase the engine speed and restart the engine.

A vehicle dynamics control device includes: a control unit that executes braking/driving torque control for controlling at least either a braking torque or a driving torque at each wheel based upon at least either external information pertaining to an environment of a vehicle or vehicle information that includes operation input information indicating an operation input by a driver and a vehicle dynamics information. And the operation input information includes a lateral motion operation index pertaining to a lateral motion operation executed to generate a lateral motion in the vehicle; the vehicle dynamics information includes a longitudinal acceleration generated in the vehicle and a lateral motion index indicating a lateral motion occurring in the vehicle; and the control unit determines a handling assurance acceleration limit with a maximum longitudinal acceleration value that assumes a substantially linear proportional relationship with the lateral motion operation index and the lateral motion index over a range in which the lateral motion operation index assumes a value equal to or less than a predetermined value or the lateral motion index assumes a value equal to or less than a predetermined value, and executes the braking/driving torque control by setting the handling assurance acceleration limit as an upper limit to a longitudinal acceleration to be generated in the vehicle under the braking/driving torque control.

Methods are provided for controlling a vehicle speed during a downhill travel. Based on the estimated grade of the downhill travel and further based on an input received from the operator, different combinations of an engine braking torque and a regenerative braking torque are used to maintain the vehicle speed during the downhill travel. A battery rate of charging is also adjusted based on the duration or distance of the downhill travel, as indicated by the operator input.

A method for providing an estimate of brake pad thickness. The method employs fusion of sensors, if used, and driver brake modeling to predict the vehicle brake pad life. An algorithm is employed that uses various inputs, such as brake pad friction material properties, brake pad cooling rate, brake temperature, vehicle mass, road grade, weight distribution, brake pressure, brake energy, braking power, etc. to provide the estimation. The method calculates brake work using total work minus losses, such as aerodynamic drag resistance, engine braking and/or braking power as braking torque times velocity divided by rolling resistance to determine the brake rotor and lining temperature. The method then uses the brake temperature to determine the brake pad wear, where the wear is accumulated for each braking event. A brake pad sensor can be included to provide one or more indications of brake pad thickness from which the estimation can be revised.

A wheel speed transducer including a magnetic device associated with a wheel and a sensor device associated with the axle of the wheel provides data indicative of the velocity of the wheel. A processor located at the axle receives the wheel speed data and processes it to perform antiskid control functions. The velocity data is stored in a data concentrator also associated with the axle. A tire pressure sensor, a brake temperature sensor and a brake torque sensor, each associated with the wheel, send data to the processor at the axle, for storage in the data concentrator. A transmitting antenna associated with the axle and in communication with the data concentrator transmits stored data to a receiving antenna associated with the wheel. A data port at the wheel and in communication with the receiving antenna provides an interface to an external device for receiving the data.

Disclosed herein is an adaptive cruse control method on an incline to improve traveling performance and stoppage maintenance performance on an incline. During adaptive cruise control, a gradient of a road is estimated based on a vehicle acceleration and longitudinal acceleration to enable compensation of a resistance torque with respect to the gradient of the road, which prevents deterioration of a traveling speed of a vehicle on an incline. Also, compensating for a brake torque to prevent the vehicle from being pushed rearward when the vehicle is stopped or starts to go on an incline may prevent deterioration of performance on an incline.

A hybrid propulsion system for a vehicle. The hybrid propulsion system including a multiple step fixed-gear transmission device for transmitting torque to a first at least one drive wheel, a first electric energy conversion device coupled to an input of the multiple step fixed-gear transmission device, and a control system, during a deceleration condition, the control system increasing negative torque output of the first electric energy conversion device to meet a desired wheel braking torque in response to the multiple step fixed-ratio transmission transitioning from a first gear ratio to a second gear that is higher than the first gear ratio.

The occurrence or non-occurrence of a certain slip of a drive wheel is detected based on only a motor torque used for driving a vehicle, a brake torque, and a rotation speed of a motor computed from an output of a rotational position detection sensor. In response to detection of the occurrence of the certain slip, drive restriction of the motor is activated for slip control. This arrangement enables effective slip control by the simple configuration. The slip control is attainable by multiple different mechanisms, that is, a brake system and the drive restriction of the motor. Even in the event of any failure or abnormality arising in the brake system or in the event of prohibiting traction control of the brake system in response to the driver's operation of a TRC off switch, the drive restriction of the motor accomplishes the slip control. This arrangement desirably prevents slip-induced unstable driving of the vehicle and damages of devices involved in slip control for the vehicle.