SE466440B - Arrangement for propulsion control in motor vehicles - Google Patents

Abstract

An arrangement for propulsion control in motor vehicles, for preventing unwanted rotational slippage of the driven wheels 5, 6 when their slippage exceeds a predetermined threshold value, includes a plurality of slippage thresholds which are coupled in/out as a function of signals which are formed by the vehicle speed, lengthwise acceleration, control angle and control signals for the propulsion control. Control signals can also be used to change the advance or reverse speeds for the adjustment elements which act to regulate propulsion. <IMAGE>

Description

Åse 440 control of parameters in logical processes in drive slip control. This refers in particular to the possibility of changing the switching thresholds for control signals such as positive and negative wheel accelerations, etc. insofar as such control signals find use in the forward drive control device.

A further advantage of the use of the longitudinal acceleration signal lies in the fact that it can be used for switching the increase and decrease speed of the brake pressure for ASR-regulated wheels and for the displacement speed for the power setting elements of the vehicle engine. At smaller longitudinal accelerations, the reduction speed of the brake pressure and the recovery speed of the motor torque, respectively, after an ASR operation, occur slowly, so that the regulated wheel with small torque excess is brought in the direction of the unstable area.

With large longitudinal acceleration, ie higher coefficients of friction, this speed of adjustment can be considerably greater because in this case the excess torque is not too great even with strong engines. This control has special advantages in inhomogeneous lanes, especially when the so-called u-jump occurs, because then the ASR device temporarily comes into operation. The longitudinal acceleration can also be derived from a travel speed sensor through a correspondingly larger insert. Sensors are known which operate according to the Doppler radar principle or the principle of optical correlation. Likewise, the longitudinal acceleration can be evaluated with appropriate accuracy, based on the time course of the average values of the wheel speeds.

Further details of the invention appear from the subclaims and the following description of an exemplary embodiment.

The drawing shows the known drive slip control device schematically and only to the extent required for understanding it. In the box 1 which is supplied as input signals to the wheel speed signals produced by the wheel speed sensors DF, the electronics for the drive slip control (hereinafter referred to as ASR) are placed, insofar as it is not separately illustrated as described below. An output signal acts on a torque controller 2, which, in order to effect a reduction in power, acts on the control element - here indicated as a throttle 3 - in the vehicle engine (not shown). 466 440 The mode of action of ASR is assumed to be known. It is described in detail in patent specification DE-PS 3 127 302.

The control angle sensor 7 and the control angle comparator 8 set at a predetermined threshold value of, for example, 300 form part of the ASR electronics, as well as the longitudinal acceleration sensor 9 and the two control angle comparators 10 and 11 connected thereto at different threshold values for the longitudinal acceleration. 10 set to a value of 0.1g and the comparator 11 set to a value of 0.3g.

The output signals 8a of the control angle comparator 8 (8a = H when the control angle> 30o) and the output signals 10a, 11a of the two longitudinal acceleration comparators (10a = H when the longitudinal acceleration> 0.1g; 11a = H when the longitudinal acceleration> 0.3g) are led to a linkage coupling 12. This linkage coupling 12 also receives an output signal 1c from a driving speed comparator (not shown in the ASR electronics 1) (1c = H when the driving speed is, for example,> 20 km / h) and via a OR element 13 a signal called an "ASR". "signal 13a. The OR element is connected via its inputs to lines which lead the output signals 1a of the ASR electronics for the torque regulator 2 and 1b for the brake torque regulator 4, and always generates an output signal when there is at least one control signal 1a.

Arranged in the linkage coupling 2 is an AND-NOT element 15, the non-inverting input of which is applied to the output signal 10a (0.1 g) of the longitudinal accelerator comparator 10 and the output signal 11a (0.3 g) of the inverting input of which is applied to the output signal of the longitudinal acceleration comparator 11. AND the NOT element 15 (the NAND element) thus always emits an H output signal 15a when there is a signal 10a but no signal 11a, i.e. when the longitudinal acceleration is between 0.1g and 0.39.

The output signal 15a is routed to an input of an AND element 14, which has a total of four inputs.

To its other three inputs are the travel speed signal 1c, the control angle comparator 8a output signal 8a and the ASR signal 13a. The AND element 14 thus emits an H-output signal 14a if at the same time sn 466 440 4 1. the driving speed> 20 km / h, "2. the steering angle> 300, the longitudinal acceleration amounts to between 0.1g and 0, 3g, and 4. an ASR signal is present. The output signals 8a and 15a are routed to the inputs of an additional AND element 17 included in the linkage coupling 12, which emits an H output signal 17a when the control angle> 300 and the longitudinal acceleration> 0.3g.

The two output signals 14a and 17a are routed to the ASR electronics unit 1. In the ASR electronics, each driven hand is assigned three slippage comparators (not shown), which are set to an intermediate one, a relatively lower one and a relatively higher slip threshold. These slippage threshold values are formed in a known manner by values obtained by speed sensor DF and are led to the comparator inputs of the comparators.

The assigned wheel speed is compared with these values.

Depending on the output signals 14a and 17a of the linkage coupling 12, either of these three slip comparators is activated, namely: a) the comparator with the intermediate slip slip when neither of the two output signals is present (14a = L and 17a = L), b) the comparator with the lower slip threshold when the output signal 14a is present (14a = H), and c) the comparator with the higher slip threshold when the output signal 17a is present (17a = H).

In addition, in the linkage coupling 12 there is a third AND element 16 with three inputs which are applied to the travel speed 2 signal 1c, the output signal 11a of the longitudinal acceleration comparator 11 and the ASR signal. This AND element 16 emits an H output signal 16a when at the same time 1. the driving speed> 20 km / h, 2. the longitudinal acceleration> 0, 3g, and 3. an ASR signal is present.

The output signal 16a is applied to devices which are shown in broken lines and which are integrated in the motor torque regulator 2 and in the braking torque regulator 4 and are therefore not illustrated.

When there are control signals 1a and 1b, respectively, the engine torque is rapidly reduced and the brake pressure of the wheel in question is rapidly increased. After a possible retention phase after failure of the control signal, the motor torque is increased again with a certain relatively slow reset speed.

This is advantageous at a low coefficient of friction, ie. at low longitudinal acceleration, because then the wheel or the wheels can be brought back to the stability limit with a small excess of torque. At greater longitudinal acceleration, i.e. at the occurrence of the output signal 16a, the reset speed is switched to a higher value by the device integrated in the torque regulator 2, since in this case the excess torque is not too great even with powerful motors. The engine torque is thus increased again faster. In addition, if only one wheel tends to spin loose, by means of the control signal 1b a control of the braking force on the driven wheel 5 or 6, which tends to slip, can be effected via the brake control device 4. in this case the reset speed is adjusted to a higher value by means of the device integrated in the brake control device 4.

This control, mainly due to the longitudinal acceleration and the steering angle, controls the slip thresholds and the torque regulator's increase and return speeds, respectively, enables a substantial refinement of the control and an optimization of the forward driving force when driving straight ahead and of lateral stability in cornering.

Claims (2)

A device for propulsion control in motor vehicles, for preventing an undesired rotational slip of the driven vehicle wheels, including sensors of motion of the vehicle wheels sensing sensors, devices which, by the signals from these sensors, sense the driven vehicle wheels and the slip of the driven vehicle wheels. a predetermined threshold value corresponding to slip gear comparator for each driven vehicle wheel, the vehicle torque output torque being reduced when at least one driven vehicle wheel tends to rotate slip, a vehicle speed comparator activatable at a predetermined threshold speed, a vehicle and a longitudinal accelerator a predetermined threshold value activatable longitudinal acceleration comparator, as well as a steering angle sensor and a steering angle comparator activatable at a predetermined threshold value, characterized in that for each driven vehicle wheel (5,6) fhum Lvåydterl fi mre n slirni 4 skomparers, one which is activatable at a lower threshold value and one which is activatable at a higher threshold value, - a further longitudinal acceleration comparator (11) set at a predetermined higher threshold value, and - a linkage coupling (12), which is arranged_at : alternatively, activate it by these slip comparators at each drive: vehicle wheels, when there is a certain combination of the output signals from the speed comparator (signal lo), one of the longitudinal acceleration comparators (10, 11), the steering angle comparator (8) ¿and the input signals (la ) to the actuating device (2) for the motor torque acting on the actuating element (3). A device for propulsion control in motor vehicles, for preventing an undesired rotational slippage of the driven vehicle wheels, comprising sensors of motion of the vehicle wheels sensing sensors, devices which by the signals from these sensors sense the slippage of the driven vehicle wheels, and a pre-sliding throttle. 4e6 440 for each driven vehicle wheel, the output torque of the vehicle engine being reduced when at least one driven vehicle wheel tends to rotate and in addition the wheel brake for a driven vehicle wheel is activated only when this wheel tends to rotate, a vehicle rotator activating at a predetermined threshold speed the vehicle's longitudinal acceleration sensing measuring device, and a longitudinal acceleration comparator which can be activated at a predetermined threshold value, as well as a steering angle sensor and a steering angle comparator which can be activated at a predetermined threshold value, characterized by - at for each driven vehicle wheel (5, 6) there are two additional slip comparators, namely one which is activatable at a lower threshold value and one which is activatable at a higher threshold value, - a further one set at a predetermined higher threshold value longitudinal acceleration comparator (11), and - a linkage coupling (12) which is arranged to alternatively activate one of these slip comparators at each driven vehicle wheel when there is a certain combination of the output signals from the speed comparator (signal 1c), one of the longitudinal acceleration comparators (10, ), the steering angle comparator (8), and the input signal (1b) to the actuating device (4) for the wheel brakes on the driven wheels (5, 6) and the input signal (1a) to the actuating device (2) for the motor torque actuating the adjusting element (3). DJ. Device according to claim 1, characterized in that the linkage coupling (12) is arranged to activate (signal 14a) the slip comparator with the lower threshold value when there are at the same time output signals from the speed comparator (signal 1c), the control angle comparator (8), at least one input signal (1a, 1a, ) from an actuating device (2, 4) and an output signal from the longitudinal acceleration comparator (10) with the lower but not from the longitudinal acceleration comparator (11) with the higher threshold value. Device according to Claim 1 or 2, characterized in that the linkage coupling (12) is arranged to activate (signal 17a) the slip comparator with the higher threshold value when at the same time there are output signals from the control 46.6 440 ~ angle comparator (8; signal Ba) and from the longitudinal acceleration comparator (11; signal 11a) with the higher threshold value. Device according to claim 1, characterized in that the linkage coupling (12) is arranged to activate the slippage comparator with the intermediate threshold value when there is no activation signal (14a, 17a) for one of the other two slippage comparators. Device according to claim 1, characterized by a device which is intended to be activated by the linkage coupling (12, 16) when there are simultaneously output signals from the speed comparator (signal ïc), the longitudinal acceleration comparator (11, signal 11a) with the higher threshold value, and at least one input signal (1a, 1b) from an actuating device (2, 4) and which in this case causes (signal 16a) a change in the rising and / or falling speed of the brake pressure in the wheel brakes and / or the speed of the adjustment for the vehicle engine power control element (3).