POSITION AND HEIGHT CONTROL OF A DRIVER'S CAB RELATIVE TO THE VEHICLE CHASSIS

Description

[0001] The invention relates to a device for controlling the position and height of a driver's cab relative to the chassis, wherein the driver's cab is mounted on the chassis in a height-adjustable manner by means of actuators. The invention also relates to a vehicle with a driver's cab mounted and adjustable on the chassis, and to a device for controlling the position and height of a driver's cab relative to the chassis of a vehicle. Furthermore, the invention relates to a method for controlling the position and height of a driver's cab relative to the chassis of a vehicle, wherein the driver's cab is mounted on the chassis in a height-adjustable manner by means of actuators. State of the art

[0002] Driver's cabs for trucks or agricultural vehicles are usually mounted on the vehicle chassis via spring and damping elements, usually in the form of air springs. The spring and damping elements decouple the driver's cab from the chassis, absorb shocks and vibrations, and ensure pleasant driving comfort. Driver's cabs are generally passively sprung and damped. The position of the driver's cab cannot be adjusted relative to the position of the chassis. Solutions are already known from the prior art with which a driver's cab can be adjusted relative to the vehicle chassis. DE4321152A1 discloses an agricultural vehicle whose cab is mounted on the vehicle body via rubber mounts. To increase driving comfort, two additional actuators are arranged between the cab and the body, which are dependent on sensor-based position detection of the vehicle orThe cabin is operated by a control unit provided in the vehicle. Disadvantageously, this requires additional actuators for position control, which leads to increased system costs. Another example is known from US Pat. No. 5,899,288 A. Task

[0003] The invention is based on the object of developing a device and a method for controlling the position and height of a vehicle driver's cab, so that the cab inclination can be adjusted taking sensor data into account. In particular, the object is to keep the inclination plane of the driver's cab parallel to the inclination plane of the vehicle chassis while maintaining a constant height distance between the driver's cab and the vehicle chassis. In order to keep the system costs for the position and height control of the driver's cab low, a further object is to implement the solution with minimal additional sensors and maximum utilization of sensors already present on the vehicle. Solution to the task

[0004] The solution to this problem is provided by the device for controlling the position and height of a driver's cab according to independent claim 1.

[0005] Further advantageous developments are disclosed in the dependent claims.

[0006] Claim 7 discloses a vehicle with a driver's cab mounted on the chassis and adjustable and a device for controlling the position and height of a driver's cab relative to the chassis.

[0007] Furthermore, claim 8 discloses a method for controlling the position and height of a driver's cab relative to the chassis of a vehicle. Advantages of the invention

[0008] Claim 1 discloses a device according to the invention for controlling the position and height of a driver's cab relative to the chassis of a vehicle, wherein the driver's cab is mounted on the chassis in a height-adjustable manner by means of actuators. At least one of the actuators is monitored by a height sensor. The height can be monitored either via direct measurement using a height sensor located on the actuator or connected to it, or indirectly via the measurement of the distance between the driver's cab and the chassis at any measuring point that has a defined geometric relationship to one of the actuators, from which the height of the actuator can be deduced. The height measurement can be based optionally on various measuring principles. For example, the optical measuring principle using laser sensors or an acoustic measuring principle based on ultrasonic sensors should be mentioned.In addition, inductive or capacitive sensors can also be used.

[0009] In addition, a first sensor is provided on the driver's cab to determine the position of the driver's cab, and a second sensor is provided on the chassis to determine the position of the chassis. The driver's cab is mounted on the vehicle's chassis in a vibration-damping manner. Since the driver's cab and the chassis are decoupled from each other, a relative interlacing of the inclination planes, also referred to as an inclination angle difference, between the driver's cab and the chassis is possible. A first sensor is provided on the driver's cab and a second sensor is provided on the chassis to determine the respective position of the inclination planes of the driver's cab and the chassis.More specifically, the second sensor may be arranged on the chassis, on the engine, in the running gear, in the drive train or at other locations in the vehicle; however, in the context of the solution according to the invention, particularly important among these are the sensors that are rigidly mounted in or on the cabin, as well as the sensors that are rigidly connected to the chassis and a height sensor that monitors the height of at least one of the actuators.

[0010] A computing unit is designed to process the signals from the height sensor, the first sensor for determining the position of the driver's cab, and the second sensor for determining the position of the chassis. The signals from the height sensor, the first sensor, and the second sensor are used to determine the current height of the remaining actuators. If predetermined limit values are exceeded or undershot, control signals for adjusting the height of all actuators are determined and output to the actuators. The computing unit determines the interlacing or difference in the angle of inclination of the inclination planes of the driver's cab and chassis. The signal from the height sensor can also be used to draw conclusions about the height of one of the actuators. In particular, the height sensor can be used to determine the deviation of the height from the neutral position of the actuator.The neutral position of the actuator can be stored as a reference or target value in the computing unit, which simultaneously represents the target distance of the driver's cab to the chassis.

[0011] The signals from the height sensor, the first sensor for determining the position of the driver's cab and the second sensor for determining the position of the chassis can be processed in a computing unit using an algorithm which uses the signals from the height sensor for determining the height of one of the actuators and the first and second sensors for determining the position of the driver's cab and / or the chassis to determine the current height of the remaining actuators and, if predefined limit values are exceeded or undershot, determines control signals for adjusting the height of all actuators and outputs them to the actuators.

[0012] If a tilt angle difference between the driver's cab and the chassis is detected, the height-monitored actuator can be set to the calibrated setpoint, after which the other actuators can be adjusted so that the tilt angle difference between the driver's cab and the chassis equals zero or another defined setpoint. As a result, all actuators are at the same height, resulting in the driver's cab being at a defined height distance from the chassis. According to another control logic, a deviation from the setpoint of the height-monitored actuator can result in it being set to the calibrated setpoint, after which the other actuators can be adjusted so that the tilt angle difference between the driver's cab and the chassis equals zero or another defined setpoint.

[0013] By combining a first sensor for determining the inclination of the driver's cab and a second sensor for determining the inclination of the chassis with the height measurement of an actuator, all relevant information for position and height control of the driver's cab relative to the chassis of a vehicle can be provided. Compared to conventional considerations for height control of the driver's cab to the chassis, in which each of the actuators has a height sensor or is connected to one, the solution according to the invention can reduce the number of sensors. Taking into account an already existing inclination sensor for the chassis, an additional inclination sensor for the driver's cab and a height sensor for determining the height of one of the actuators are required for functional position and height control.With a number of three actuators, the number of sensor components in the actuator area can be reduced by just two particularly cost-intensive height sensors.

[0014] Trucks and agricultural vehicles are particularly suitable for applying the method according to the invention. While it can be advantageous in particularly rough terrain, for example when constantly driving across a slope, to align the inclination plane of the driver's cab horizontally, which deviates from the inclination plane of the chassis, it can, on the other hand, increase comfort when driving on the road if the inclination planes of the driver's cab and chassis are kept parallel. Active position control of the driver's cab is extremely advantageous, particularly for agricultural vehicles that are frequently used in rough terrain. For example, when driving across a slope, the driver's cab can be raised on the side facing down the slope, so that the driver in the cab is not exposed to lateral downhill forces and can carry out his work in a concentrated and comfortable manner for long periods.

[0015] According to a further aspect, the actuators are designed in the form of adjustable air spring elements. The use of air springs as actuators is particularly advantageous because the active position control of the driver's cab can be implemented using, in part, existing vehicle components. This enables a cost-effective implementation of the stated task. The device according to the invention can be used in all vehicles with an air-sprung or partially air-sprung driver's cab. Height-adjustable air spring elements are particularly suitable for this purpose, the distance between the pivot points on the body or chassis on the one hand and the driver's cab on the other hand being adjustable either mechanically or pneumatically.

[0016] According to a further aspect, the air spring elements are designed as spring and damping elements. This advantageously enables a particularly compact and space-saving design of a spring-damping system by combining the spring and damping functions in one air spring element.

[0017] According to a further aspect, at least one of the actuators has an integrated height sensor or is at least connected to a height sensor, so that the distance between the chassis and the driver's cab can be determined and adjusted. Height measurement can be based on various measurement principles. For example, the optical measurement principle using laser sensors or an acoustic measurement principle based on ultrasonic sensors are mentioned. Inductive or capacitive sensors can also be used.

[0018] To achieve optimal suspension, it is advantageous for the actuator to be in a central, neutral height position. This ensures optimal spring travel / adjustment for both compression and rebound. This neutral height position of the actuator can be used as a reference value for the distance between the driver's cab and the chassis. By knowing the inclination data of the driver's cab and chassis, as well as the height of at least one actuator, the tilt control of the driver's cab can be ensured with the optimal height adjustment of the individual actuators.

[0019] According to a further aspect, the first sensor and / or the second sensor is a 2- or 3-axis acceleration sensor. This offers the advantage of being able to choose from a particularly large portfolio of standard components, enabling a cost-effective implementation of the control system.

[0020] According to a further aspect, the height sensor is designed as an ultrasonic sensor. The choice of an ultrasonic sensor advantageously enables the implementation of a particularly robust and durable system.

[0021] Another embodiment provides a vehicle with the device according to the invention. Since the costs of technical components must be kept low, especially in vehicles, the device according to the invention offers the particular advantage that a large number of components already present in the vehicle are networked with one another, so that the solution according to the invention can be implemented with minimal additional costs.

[0022] Another embodiment discloses a method for controlling the position and height of a driver's cab relative to the chassis of a vehicle, wherein the driver's cab is mounted on the chassis in a height-adjustable manner using actuators. The method according to the invention comprises the following steps: Detecting the height of at least one of the actuators (3) by means of a height sensor (9), detecting the position of the driver's cab (1) by means of a first sensor (7) on the driver's cab, detecting the position of the chassis (2) by means of a second sensor (8) on the chassis, determining the current height of the remaining actuators (3) by means of a computing unit (5) from the signals of the height sensor (9), the first sensor (7) and the second sensor (8), and, if predetermined limit values are exceeded or undershot, determining the control signals for adjusting the height of all actuators (3) and outputting the control signals to the actuators (3).

[0023] A height sensor detects the height of at least one of the actuators. This can be done either directly using a height sensor located on or connected to the actuator, or indirectly by measuring the distance between the driver's cab and the chassis at any measuring point that has a defined geometric relationship to one of the actuators, from which the height of the actuator can be determined.

[0024] A first sensor on the driver's cab detects the position of the driver's cab, and a second sensor on the chassis detects the position of the chassis. A processing unit processes the signals from the height sensor to determine the height of at least one of the actuators, the first sensor, and the second sensor, using an algorithm. The current height of the remaining actuators is determined from the signals from the height sensor, the first sensor, and the second sensor. If specified limits are exceeded or undershot, control signals for adjusting the height of all actuators are generated and output to the actuators.

[0025] In other words, the algorithm continuously compares the current measured value from the height sensor with the reference value. The reference value represents the neutral height position of the actuator. As soon as a deviation from the reference value is identified, the actuator's height is adjusted to the original reference value. The height control of the remaining actuators can be achieved by compensating for the tilt angle difference, which is calculated from the sensor data from the first sensor for determining the position of the driver's cab and the second sensor for determining the position of the chassis.

[0026] Compensating the tilt angle between the driver's cab and the chassis, as well as adjusting the height-monitored actuator to its reference value, enables control of the position and height of the driver's cab relative to the vehicle's chassis. It is particularly advantageous that the control algorithm only needs to evaluate a very small amount of sensor data. This simplifies programming and reduces the risk of errors. Explanation of figures

[0027] An embodiment of the invention is explained in more detail below with reference to the drawing.

[0028] Fig. 1shows a schematic representation of the front end of a heavy goods vehicle 6 (HGV). Here, the driver's cab 1 is mounted on the chassis 2 of the truck 6 via air spring elements 3 in a vibration-damping manner. Furthermore, an inclination sensor 7 is shown on the front of the truck 6. The positioning of the inclination sensor 7 on the front of the truck 6 is chosen as an example and does not exclude other positioning options. The driver's cab 1 is mounted on the chassis 2 via three air spring elements 3, which are arranged in such a way that active adjustment of the driver's cab 1 is possible both about an axis running across the width of the cab and about an axis running along the length of the cab. This is possible because the air spring elements 3 are designed as actuators; by changing the air volume inside the air spring bellows, a change in the height of the air spring element 3 occurs, which is directly transferred to the driver's cab 1 mounted on it.The air volume is changed by opening valves in front of the respective air suspension elements, which are connected to a compressed air supply. By coherently controlling each of the individual air suspension elements 3, the position of the driver's cab 1 about its longitudinal and / or transverse axis can be controlled. The data required for position control is obtained from the information from the inclination sensor of the driver's cab 7, the inclination sensor of the chassis 8, and the height sensor 9 of one of the three air suspension elements, combined within a computing unit 5 and evaluated to output control signals to the individual air suspension elements 3. The height sensor 9 can, as shown in . Fig. 1shown, be integrated into the air spring element 3, but can also be connected to the air spring element 3 as an external sensor or be installed at any measuring point for measuring the distance between the driver's cab 7 and the chassis 8, wherein the measuring point is in a defined geometric relationship with the air spring element 3 for determining the height of the air spring element.

[0029] The inclination sensors 7, 8 describe the position of the levels of the driver's cab 1 and the chassis 2. The information from the inclination sensors 7, 8 is evaluated in the computing unit 5, whereby a difference in the inclination angle is determined. This difference in the inclination angle is calculated in two axes, with one axis describing the vehicle's longitudinal axis and the second axis the vehicle's transverse axis. As a further controlled variable, the height of an air spring element 3 is determined via the height sensor 9. The height sensor 9 is calibrated to a setpoint value that corresponds to the middle, neutral height position of the air spring element 3. In this position, the air spring element 3 has the optimal compression and rebound travel. The calibrated setpoint of the height sensor 9 represents the reference value for the distance between the driver's cab 1 and the chassis 2.If a tilt angle difference is detected between the driver's cab 1 and the chassis 2, the height-monitored air spring element 3 is adjusted to the calibrated target value, whereupon the remaining air spring elements 3 are adjusted such that the tilt angle difference between the driver's cab 1 and the chassis 2 is zero. As a result, all air spring elements 3 are at the same height level, whereupon the driver's cab 1 is at a defined height distance from the chassis 2. List of reference symbols

[0030] 1Driver's cab 2Chassis 3Adjustable air suspension element 5Computer unit 6Vehicle 7First tilt sensor on the driver's cab 8Second tilt sensor on the chassis 9Height sensor

Claims

1. Device for controlling the position and height of a driver's cab (1) relative to the chassis (2) of a vehicle, wherein the driver's cab (1) is mounted on the chassis (2) so as to be height-adjustable using actuators (3), wherein at least one of the actuators (3) is monitored via a height sensor (9), wherein a first sensor (7) is provided on the driver's cab for the purpose of determining the position of the driver's cab (1), wherein a second sensor (8) is provided on the chassis for the purpose of determining the position of the chassis (2), characterized in that a computing unit (5) is designed to process the signals from the height sensor (9), from the first sensor (7) and from the second sensor (8) in such a way that the current height of the remaining actuators (3) is determined from the signals from the height sensor (9), from the first sensor (7) and from the second sensor (8) and, if predefined limit values are exceeded or undershot, control signals for adjusting the height of all actuators (3) are determined and output to the actuators (3).

2. Device according to Claim 1, characterized in that the actuators (3) are in the form of adjustable air spring elements (3).

3. Device according to Claim 2, characterized in that the air spring elements (3) are designed as spring and damping elements (3).

4. Device according to one of the preceding claims, characterized in that the height sensor (9) is integrated in the actuator (3) or is connected to the actuator (3).

5. Device according to one of the preceding claims, characterized in that the first sensor (7) and / or the second sensor (8) is / are a 2-axis or 3-axis acceleration sensor (7, 8).

6. Device according to one of the preceding claims, characterized in that the height sensor (9) is designed as an ultrasonic sensor (9).

7. Vehicle having an adjustable driver's cab (1) mounted on the chassis (2) and a device for controlling the position and height of a driver's cab (1) relative to the chassis (2) of a vehicle according to one of the preceding claims.

8. Method for controlling the position and height of a driver's cab (1) relative to the chassis (2) of a vehicle, wherein the driver's cab (1) is mounted on the chassis (2) so as to be height-adjustable using actuators (3), wherein the method comprises at least the following steps: detecting the height of at least one of the actuators (3) by means of a height sensor (9), detecting the position of the driver's cab (1) using a first sensor (7) on the driver's cab, detecting the position of the chassis (2) by means of a second sensor (8) on the chassis, characterized by at least the steps of: determining the current height of the remaining actuators (3) from the signals from the height sensor (9), from the first sensor (7) and from the second sensor (8) using a computing unit (5), and, if predefined limit values are exceeded or undershot, determining the control signals for adjusting the height of all actuators (3) and outputting the control signals to the actuators (3).