Method and device for detecting torque request of driver in motor vehicle

Abstract

The invention relates to a method and a device for detecting a torque request of a driver in a motor vehicle, in which: a driver force value is detected by means of a sensor which is arranged in the interior of the motor vehicle and is designed to be immovable; the driver force value represents a pressing force applied to the sensor by the driver and / or a pressing force applied to the sensor by the driver; determining a pressing force correction value dependent on an instantaneous change in the chassis orientation of the motor vehicle; -determining a torque request of the driver with respect to a torque applied to at least one wheel of the motor vehicle as a function of the driver force value and the pressing force correction value; and-applying a torque to the at least one wheel of the motor vehicle as a function of the torque request.

Description

Background Art

[0001] Document DE 102 39 913 A1 discloses an actuating mechanism for influencing a braking system, clutch system, or drive system of a motor vehicle, wherein the actuating mechanism actuated by the driver is mechanically decoupled from the actuators of the system. The actuating mechanism is a sensor that specifically detects the driver's actuating force and generates a control signal that is generated independently of the actuating path. The actuating mechanism has no actuating path. Summary of the Invention

[0002] The present invention relates to a method and a device for identifying a driver's torque request in a motor vehicle, wherein:

[0003] - detecting a driver force value by means of a sensor arranged in the interior of the motor vehicle and designed to be immovable, the driver force value representing the pressing pressure exerted by the driver on the sensor and / or the pressing force exerted by the driver on the sensor;

[0004] - determining a pressing force correction value associated with a momentary change in the orientation of the chassis of the motor vehicle;

[0005] - determining a driver's torque request for a torque to be applied to at least one wheel of the motor vehicle as a function of the driver's force value and the pressing force correction value; and

[0006] - applying a torque to the at least one wheel of the motor vehicle in dependence on the torque request.

[0007] The driver force value, also known as the pressing force value, represents the force acting between the driver's foot and the sensor. Movement, undulation, bounce, or rebound of the chassis or body also generates forces on the sensor. This force can press the sensor more tightly against the driver's foot, increasing the driver force value beyond the driver's intended value. However, particularly through bounce, the sensor can also move downward and away from the driver's foot, weakening the driver's intended pressing force.

[0008] An advantageous embodiment of the invention is characterized in that the pressing force correction value is determined by means of a mathematical model from sensor data of driving dynamics.

[0009] An advantageous embodiment of the invention is characterized in that the pressing force correction value is determined with the aid of data from a sensor system, in particular a video sensor system, a radar sensor system or a GPS sensor system, or a position detection sensor system.

[0010] An advantageous embodiment of the present invention is characterized in that the torque is a braking torque. This braking torque can be applied either by wheel-specific brake components or by a conventional braking system with hydraulic brake actuators and a vehicle stability system. Combinations of electric and hydraulic brake components are also possible. Braking torque can also be applied by regenerative deceleration.

[0011] An advantageous embodiment of the invention is characterized in that the motor vehicle is a two-track motor vehicle and in that the braking torque is a braking torque applied to two wheels of at least one axle.

[0012] An advantageous embodiment of the invention is characterized in that the torque is a driving moment.

[0013] An advantageous embodiment of the invention is characterized in that the sensor is arranged in the footwell of the motor vehicle and is actuated by the driver's foot.

[0014] An advantageous embodiment of the present invention is characterized in that the sensor is made of a piezoelectric material.

[0015] An advantageous embodiment of the present invention is characterized in that the sensor is made of a membrane that detects micro-movements.

[0016] The present invention also encompasses a device comprising means for executing the method according to the present invention. In this case, the device is, in particular, a controller storing program code for executing the method according to the present invention. The controller can be a dedicated controller, such as a brake controller or a motor controller, or a central controller. Of course, the pressing force correction value can also be calculated in a computing device external to the vehicle, such as in the cloud.

[0017] An advantageous embodiment of the invention is characterized in that the change in the chassis orientation is actively determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings include Figure 1 and Figure 2 .

[0019] Figure 1 A longitudinal section of a motor vehicle is shown schematically.

[0020] Figure 2 The basic flow of the design solution of the method according to the present invention is shown. DETAILED DESCRIPTION

[0021] The present invention aims to detect a driver request (in the example illustrated here, a driver braking request) as accurately as possible and thus to implement the vehicle deceleration requested by the driver.

[0022] Changes in the movement of the motor vehicle's chassis caused by external influences can lead to deviations in the pressure applied by the driver's foot to the sensor. To set a braking request, the driver presses the sensor with his foot, wherein the braking intensity or degree requested by the driver is set by means of the pressure or pressing force.

[0023] The driver's braking request is usually set during driving, so that regular movement changes of the chassis occur. These movement changes can be caused, for example, by road unevenness, potholes, bends or changes in road gradient.

[0024] Because the driver's foot presses against the sensor from above during braking, these changes in motion exert a reaction force on the sensor from below. Therefore, the force detected by the sensor includes the force applied by the driver with his foot and the reaction force applied by the changes in chassis motion.

[0025] Since the sensor is directly connected to the body of the motor vehicle, the reaction forces are amplified, while the movements of the driver and his feet are damped by the driver's seat, so that the body or chassis only moves in a damped manner.

[0026] This counterforce can be calculated or at least approximately estimated using a mathematical model from sensor signals, for example, of a spring travel sensor or a vertical acceleration sensor.

[0027] When driving smoothly on a very flat road, this reaction force is very small, but when driving over a pothole, for example, this reaction force can take on large values.

[0028] This determined counterforce can be added as a correction term to the pressing force detected by the sensor, thereby determining the pressing force intended by the driver, which can then be input into the brake control system.

[0029] Figure 1 A longitudinal section of a motor vehicle is shown schematically and not to scale. The motor vehicle moves from right to left using front wheels 101 and rear wheels 102. The driver's seat is designated 103. In front of the driver's seat is a sensor 104, which is fixed and immovable in the footwell.

[0030] When intentionally braking, the driver applies force 105 with his foot to sensor 104. However, if the vehicle simultaneously drives over, for example, a pothole, forces such as those shown, 106 and 107, act on the chassis or body as the vehicle drives over. These forces are transmitted to sensor 104, so that the force acting on the sensor differs from force 105 requested by the driver. The force acting on the chassis can be estimated from the sensor data using a mathematical model and thus recalculated from the output signal of sensor 104.

[0031] Figure 2The basic flow of the embodiment of the method according to the present invention is shown. After the method is started in block 200, a driver force value is detected in block 201 using a sensor 104 arranged in the interior of the motor vehicle and designed to be immobile. Subsequently, a chassis force value is detected in block 202 and transmitted to sensor 104, which is either light or heavy depending on the intensity of the chassis movement.

[0032] In block 203 , the output signal of sensor 104 is corrected with the aid of the chassis force value determined in block 202 so that it corresponds to the driver force value.

[0033] Subsequently, in block 204 , a driver's torque request for a torque to be applied to at least one wheel of the motor vehicle is determined using the corrected output signal of sensor 104 and applied to the at least one wheel. The method ends in block 205 .

Claims

1. A method for identifying a driver's torque request in a motor vehicle, wherein: - detecting a driver force value (105) by means of a sensor (104) arranged in the interior of the motor vehicle and designed to be immovable, the driver force value representing the pressing pressure exerted by the driver on the sensor and / or the pressing force (201) exerted by the driver on the sensor; - determining a pressing force correction value (202) associated with a momentary change in the orientation of the chassis of the motor vehicle; - determining a driver's torque request (204) for a torque to be applied to at least one wheel of the motor vehicle based on the driver's force value and the pressing force correction value; as well as - applying torque to the at least one wheel of the motor vehicle in accordance with the torque request (204).

2. The method according to claim 1, characterized in that The pressing force correction value is determined using a mathematical model from sensor data of driving dynamics.

3. The method according to claim 1, characterized in that The pressing force correction value is determined with the aid of data from a sensor system, in particular a video sensor system, a radar sensor system or a GPS sensor system.

4. The method according to claim 1, wherein The torque is the braking torque.

5. The method according to claim 1, wherein The motor vehicle is a dual-track motor vehicle, and the braking torque is a braking torque applied to two wheels of at least one axle.

6. The method according to claim 1, characterized in that The torque is the driving moment.

7. The method according to claim 1, characterized in that The sensor is arranged in a footwell of the motor vehicle.

8. The method according to claim 1, characterized in that The sensor is made of piezoelectric material.

9. The method according to claim 1, characterized in that The sensor is made of a membrane that detects micro-movements.

10. The method according to claim 1, characterized in that A change in the chassis orientation is actively determined.

11. A device comprising means designed to carry out the method according to the invention.

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