Abstract:
A system for controlling motor vehicle driving force comprises means for detecting the rotational speed of each of the driving wheels and a driven wheel, means for controlling brake means for the driving wheels according to the output of the detecting means, first comparing means for comparing the rotational speed of the driving wheels with the rotational speed of the driven wheel, calculating means for determining a slipping ratio corresponding to the ratio of the rotational speed of the driving wheels to the rotational speed of the driven wheel, second comparing means for comparing the output of the calculating means with a predetermined threshold slipping ratio, third comparing means for comparing the rotational speed of the driven wheel with a predetermined reference speed, and switching means for connecting the output of the first comparing means to the control means when the rotational speed of the driven wheel is lower than the predetermined reference speed and connecting the output of the second comparing means to the control means when the rotational speed of the driven wheel is higher than the predetermined speed. The switching means is changed by the output of the third comparing means. A method of controlling motor vehicle driving force also is disclosed.
Abstract:
A synchronous wheel-slip control system for a multi-axle vehicle having a speed sensor for producing signals representative of the velocity of each of the wheel axle units. A differentiator connected to each of the speed sensors for differentiating the velocity signals to obtain rate signals. A plurality of truck and car rate comparators for determining when all the wheel axle units are in synchronism. A plurality of truck and car highest velocity circuits for determining the actual highest velocity signal of the wheel axle units and a car differentiator for differentiating the actual highest velocity signal to obtain the actual highest rate signal. A synchronous slip logic network for causing a data processing circuit to initiate a brake force reduction action of one of the trucks when all the wheel axle units are in synchronism and when the actual highest rate signal exceeds a requested rate.
Abstract:
To provide for close adaptation of braking performance by braking pressure maintenance, braking pressure dropping, or braking pressure increase to match wheel acceleration or deceleration, and operating constants within the overall braking system, the wheel anti brake-lock responds when wheel deceleration drops below a predetermined reference threshold. Wheel speed is sensed in steps, for example in intervals of 0.25 km/h, and the steps are counted. A predetermined brake pressure decrease time (t.sub.min) is initiated when wheel speed drops below the reference wheel speed, the total time (t.sub.a) of pressure decrease being the minimum time plus a number of first control time intervals (.DELTA..sub.1t) which depend on the number of speed steps being passed by the wheel as it decelerates. If the wheel speed, after the pressure decrease, does not decelerate at the same rate anymore, a pressure maintenance phase is commanded for a maximum time (.DELTA..sub.2t) which, however, is foreshortened by second control timing intervals (.DELTA..sub.2t) in dependence on the wheel passing further speed steps or stages. If the wheel should decelerate substantially (.lambda..sub.2) or drop below a deceleration threshold (-b), a further pressure decrease phase can be immediately initiated, overriding the pressure maintenance phase. The first and second control timing intervals can also be made dependent on each other.
Abstract:
A vehicle anti-skid braking system, particularly for articulated vehicles, in which a fail-safe device is incorporated to disable the braking-releasing function if a skid signal is generated during the initial period of operation of the braking system before the brakes have been effectively applied.
Abstract:
To reduce disturbance and interference signals, and particularly recurring disturbance signals due to vibration or out-of-round conditions of rotating elements coupled to a speed transducer, a low-pass filter (11) is connected to the speed transducer and, in addition, a high-pass filter (12) which, however, is disconnected upon sensing that the speed of the wheel or of the vehicle is below a predetermined limit, or that the anti brake-lock system unit (13) has responded. Thus, disturbance signals, and particularly periodic disturbance signal which might cause oscillatory conditions to arise in the filter and transducer circuitry, are effectively suppressed. To further increase the reliability of response, the output from the filter circuits is connected to threshold circuits with a variable threshold level in which comparators compare a peak signal with a weighted, then existing signal, so that the comparison level threshold is continuously shifted based on previously occurring peaks, so that disturbance signals are reliably excluded from affecting signal processing within the anti brake-lock system unit (13).
Abstract:
An anti-skid brake control device and associated method in which the device includes a wheel cylinder having defined therein a first hydraulic chamber connected with a brake fluid line extending from the master cylinder and a second hydraulic chamber connected with a pressure controlling fluid circuit. As the brake fluid line is isolated from the pressure controlling circuit by the output member of the wheel cylinder, the brake system can operate effectively, though in a conventional manner, should oil leakage occur in the controlling circuit. On a four-wheeled vehicle, each pair of front or rear wheel cylinders can be served by a common arrangement of such pressure controlling circuit for anti-skid control.
Abstract:
An apparatus for adjusting the braking force of brakes applied to vehicle wheels in which the brakes are operated under the control of an electromagnet as a function of the deceleration and acceleration of the wheels. For a given braking signal, the braking force is eliminated when the deceleration of the braked wheel exceeds a predetermined threshold value, which may occur, for example, when the wheel starts to freely skid, and the reapplication of the braking force is delayed for a period of time proportional to the magnitude of deceleration of the wheel and inversely proportional to the subsequent magnitude of acceleration of the wheel when it picks up speed only when such acceleration exceeds a threshold which permits the wheel to gain speed irrespective of the frictional adherence of the wheel to the ground.
Abstract:
A velocity at the time when the accelerator of a vehicle is released is stored under a certain condition in advance, and the stored vehicle velocity and an actual vehicle velocity are compared. When the actual vehicle velocity becomes greater than the stored vehicle velocity by a predetermined value, the downward inclination of a running road surface is regarded as exceeding a predetermined value, and safety means such as a brake is driven. As compared with a case of employing an inclination angle sensor such as a mercury switch, the device operates accurately without being influenced by a change in the vibration or acceleration of the vehicle.
Abstract:
A brake force controller for vehicles, particularly automotive vehicles, with a back-control of the brake pressure of the pressure control medium for enabling various control conditions in response to input signals. The input signals are formed in accordance with sensed conditions including at least one of circumferential wheel force, pressure in the master brake cylinder, pressure in the wheel brake cylinder, a predetermined critical or limit pressure in the wheel brake cylinder, the pressure in the wheel brake cylinder when the maximum is exceeded which is stored, and first and second time intervals corresponding to the length of time predetermined control conditions are effective, respectively. In accordance with the signals, the back-control is effective for enabling control conditions of rapid pressure increase, pressure decrease, pressure maintained and gradual pressure increase.
Abstract:
A disc adapter for attaching rotatable discs of a disc brake system to a wheel is modified to include an exciter ring of a sensor unit of an anti-skid system used in conjunction with the braking system. The exciter ring is oriented co-axially with the wheel and contains a plurality of equally and annularly spaced ripples. Rotational movement of the exciter ring and the wheel is detected by a stationary magnetic pickup device adjacent to the exciter ring.