摘要:
A method and apparatus for controlling brakes using a reciprocating cut valve actuated by an expander piston that is moved via a crank pin on a crank shaft. The cut valve cuts off caliper pressure and adjusts the volume and pressure of an output hydraulic chamber to effectuate antilock braking. When changing from antilock braking to normal braking, the movement of the expander piston is controlled by repeatedly changing a crank angle of the crank pin during specified time intervals. The rate of increase in caliper pressure can be set according to (1) detected brake operation which is detected from a present crank angle and a target crank angle and (2) the frictional state of the road surface which is estimated from vehicle acceleration/deceleration.
摘要:
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. If both the inlet and outlet valves are operated (i.e. opened and closed respectively), then in response to the increased pressurized fluid, the modulator effects a decrease in caliper pressure to reduce braking. The above is summarized in FIG. 2.Thus it is seen that the brake control is effected by setting a threshold value for each of the slip ratio .lambda. and the acceleration/deceleration .alpha., and determining whether the actual state of each wheel (i.e. .lambda.and .alpha.), is at their respective threshold value or above (less). It is thus necessary to set processing times as short as possible to improve the operating speed of an actuator which executes the process referred to above. However, there are limitations on the operating speed of the actuator, and an improvement is actually difficult to achieve.In another prior art system, the modulator comprises an input hydraulic chamber which communicates with a master cylinder, for
摘要:
A method of and an apparatus for estimating a vehicle velocity, which are suitable for use in a vehicle. Velocities of drive wheels and follower wheels of the vehicle are determined and the fastest one of the so-determined velocities is selected. The velocity of the vehicle is estimated based on the fastest wheel velocity thus selected. The above respective processes are repeatedly executed at given time intervals. Thus, when the estimated vehicle velocity is faster than each of the velocities of the follower wheels and lower than the fastest wheel velocity, the estimated vehicle velocity determined immediately before the above estimating process is set as a desired estimated vehicle velocity. Accordingly, a high-accuracy estimated vehicle velocity corresponding to an actual vehicle velocity can be obtained, thereby making it possible to control brakes and driving forces with high accuracy using the estimated vehicle velocity.
摘要:
Disclosed is a method of and a system for controlling antilocking brakes employed in a vehicle such as a motorcycle. The position of an expander piston which constitutes an antilocking modulator is detected and the torque of a rotative drive source for actuating the expander piston is detected. A braking force used for each of the brakes is then computed from the detected position of the expander piston and the detected torque of the rotative drive source at the detected position. Further, friction coefficients of a road surface are estimated from the braking force thus computed and a target slip ratio is estimated from the estimated friction coefficients so as to carry out the optimum braking. Accordingly, the optimum target slip ratio can be estimated depending on high and low .mu. roads, thereby making it possible to provide satisfactory braking.
摘要:
Disclosed herein is a method of and a system for controlling brakes. In the brake control system, grounding loads on front and rear wheels are determined and a correction value for the braking of a predetermined wheel is computed based on the grounding loads thus determined. A braking force is determined inclusive of the computed correction value. A correction value for the braking of the front wheel is computed based on the determined grounding loads. Thus, the optimum brake control can be made without being affected by a variation in the distribution of the loads of the front and rear wheels relative to the ground.
摘要:
A system for monitoring and controlling a running condition of a motor vehicle such as a motorcycle has a wheel speed sensor and first and second CPUs. The first and second CPUs effect in a first mode, i.e., when an anti-lock brake control mode is not effected, the same calculations to produce calculated data to monitor the running condition of the motor vehicle, and compare the calculated data from each other to check the effected calculations. In a second mode, i.e., when the anti-lock brake control mode is effected, the first CPU continues the calculations to produce calculated data to monitor the running condition of the motor vehicle, and the second CPU performs an auxiliary controlling function for controlling the running condition of the motor vehicle by controlling a brake mechanism in the anti-lock brake control mode.
摘要:
An electric-power-assist transmission and a shift control method which allow good operability to be obtained. In the shift control method, a sleeve is engaged with a target gear. A shift spindle is rotated by a driving motor in order to move the sleeve along a main shaft by using a shift fork and a shift drum interlocked with the shift spindle. When the sleeve is moved to a position in contact with the target gear, PWM control is executed at a duty ratio of 70% during the first 20 ms. Thereafter, the PWM control is executed by changing the duty ratio to 50% and restoring the duty ratio back to 70% repeatedly at intervals of 10 ms.
摘要:
A method of and a system for controlling brakes. A target slip ratio of each of wheels at the start of antilock control is estimated and a vehicle deceleration prior to the start of the anti-lock control is detected. The target slip ratio at the start of the antilock control is corrected based on the detected vehicle deceleration. Thus, vehicle controllability correlated to the vehicle deceleration can be prevented from being impaired. It is therefore possible to reliably improve the control performance of a vehicle and to effect the optimum brake control.
摘要:
It is an object of the present invention to provide a shift control method for an electric-power-assist transmission having excellent operability. In the shift control method, a main clutch is put in an engaged or disengaged state in a manner interlocked with the rotation of a shift spindle, and the main clutch is put back in an engaged state after being released from an engaged state by the rotation of the shift spindle with a rotational speed thereof changed from a high speed to a low speed with predetermined timing.
摘要:
In the battery charging device of the present invention, a U, V, W phase voltage generating circuit detects a voltage signal of a U phase sub-coil of a three-phase alternating current generator, and generates a signal of a triangular wave that is in synchronization with the U phase. Moreover, a first triangular wave is generated in synchronization with a phase from 0° to 180° of the U phase rectangular wave, and a second triangular wave is generated in synchronization with a phase from 180° to 360° of the U phase. In addition, a V phase rectangular wave is generated in which the level is inverted at a voltage point of two thirds the peak voltage of the first triangular wave, and in which the level is inverted at a voltage point of two thirds the peak voltage of the second triangular wave, and a W phase rectangular wave is generated in which the level is inverted at a voltage point of one third the peak voltage of the first triangular wave, and in which the level is inverted at a voltage point of one third the peak voltage of the second triangular wave.