System for controlling the steering of a wheeled vehicle

Abstract

System for controlling the steering of a wheeled vehicle with one or more steerable wheels and mechanical steering, comprising: - a steering wheel for manual operation of the mechanical steering by the driver; - a steering axle connected to the steering wheel and rotatable by rotation of the steering wheel, the rotation of the steering axle being converted into a steering movement of the steerable wheels; - an electric motor for operating the mechanical steering; - a control unit for controlling the electric motor; - a manual input device, such as a joystick, to activate the control unit in auxiliary input mode; - wherein the input device is configured to transmit control signals to the control unit, wherein the control unit converts the control signals in the auxiliary input mode into steering commands for controlling the electric motor, characterized in that - the electric motor comprises a direct drive with stator and rotor, wherein the rotor is arranged in extension of the steering axis, wherein the rotor is designed to rotate the steering wheel and the steering axis simultaneously.

Description

TECHNICAL FIELD

[0001] The invention relates to a system for vehicles with motorized steering wheel rotation. In particular, the invention relates to commercial vehicles equipped with such a system. In particular, the invention relates to a system according to the preamble of the independent claim. BACKGROUND OF THE INVENTION

[0002] In vehicles such as cars or trucks, the steering of the steerable wheels is usually achieved by manually operating (i.e. turning) a steering wheel, with this manual rotation being mechanically translated into rotation of the steerable wheels. Steerable wheels are usually the front wheels, as in trucks, but can also include the rear wheels, as in a forklift truck. Heavy machinery such as large wheel loaders do not use typical automotive steering mechanisms. Instead, steering is achieved via a hydraulically operated pivot point precisely between the front and rear axles. This is called articulated steering and allows for a rigid front axle. Even some tracked vehicles can be equipped with a conventional round steering wheel to control track traction.

[0003] Such a conventional steering wheel typically consists of a manually operated wheel that can be turned by the operator (hereinafter "driver"). The steering wheel is mounted directly on a steering axle, which mechanically rotates the steering wheels. The steering can be assisted by a power steering system, which assists the rotation of the steering axle.

[0004] There are devices or systems that further facilitate steering, such as a so-called steer-by-wire control system, which mechanically decouples the steering wheel from the steering axis. Steering can then be performed using any input device. A joystick is often the preferred input device. A joystick generally comprises an assembly consisting of a body and a lever that can be moved in one direction by pressing. Typically, the directions that can be implemented are forward, backward, left, or right, but there are also joystick configurations that allow pressing in all directions 360 degrees. In this case, pressing the lever in the left forward position, for example, can be translated into a combination of forward and left movement. Joysticks are often equipped with electronic circuits that convert the movement of the stick into one or more signals or a signal stream.Joysticks are usually self-centering, meaning that as soon as the joystick is released, it returns to its central starting position through a spring action.

[0005] Below, some publications describing various steering control systems are discussed.

[0006] US patent application US 2004 / 0039507 A1 describes a steer-by-wire control system. It includes a wheel actuation system that controls the wheel angles to follow a wheel reference angle, and a steering wheel control system that generates a steering wheel angle for the wheel actuation system, steering feel for the vehicle operator, and active steering wheel feedback. The steering wheel control system further includes a steering wheel model adaptation controller that receives an input signal from the steering wheel control system and an input signal from the road wheel control system and generates a control output signal based on a model adaptation control input. The control output signal controls a reaction torque of the steering wheel control system to generate steering feel for the driver and to control the return rate of a steering wheel or joystick.

[0007] The Japanese patent application JP 2000 / 318587 A describes a device for operating the motor vehicle drive, which provides a braking sensation via a joystick during emergency braking and offers brake assistance.

[0008] European patent application EP 0525817 A1 describes a system that allows a vehicle to be equipped with a single inflatable cushion (airbag). When deflated, this cushion is housed in a housing that extends across the entire width of the dashboard and protects both the driver and the passenger sitting next to them in the event of an accident. The steering system includes a lever that moves in a single plane, replacing the steering wheel of conventional vehicles. An electronic circuit adjusts the angular position of the vehicle's wheels to the position of this lever.

[0009] A disadvantage of previous solutions is that the systems are comparatively complex and, due to the numerous necessary adjustments to the basic steering system, must be planned or installed in a vehicle during the production process. This increases vehicle costs, and these support systems are not always needed by all drivers of such vehicles in every situation. SUMMARY OF THE INVENTION

[0010] The object of the present invention is to provide a system for controlling the steering of a wheeled vehicle that can be flexibly integrated into a vehicle and that interferes with its mechanical, electrical, and electronic structures as little as possible. Furthermore, a cost-effective retrofit solution for such a system is to be provided. Another object of the invention is to realize the provision of an ergonomic steering assistance system that is intuitive to operate, requires little force, and is flexible enough to be used specifically by the driver.

[0011] This object is achieved by a system for controlling the steering of a wheeled vehicle according to claim 1. Advantageous developments of the invention are explained in the respective subclaims. The features of the exemplary embodiments described below can be combined with one another, unless explicitly stated otherwise. In particular, this object is also achieved by the following aspect and, in addition, by features of further embodiments.

[0012] One aspect of the invention relates to a system for controlling the steering of a wheeled vehicle with one or more steerable wheels and mechanical steering, comprising: - a steering wheel for manual operation of the mechanical steering by the driver - a steering axle connected to the steering wheel and rotatable by rotation of the steering wheel, the rotation of the steering axle being converted into a steering movement of the steerable wheels; - an electric motor to operate the mechanical steering and - a control unit for controlling the electric motor; - a manual input device, such as a joystick, to activate the control unit in auxiliary input mode; - wherein the input device is configured to transmit control signals to the control unit, wherein the control unit converts the control signals in the auxiliary input mode into steering commands for controlling the electric motor, wherein the rotor is arranged in extension of the steering axis.

[0013] The rotor is designed to rotate the steering wheel and the steering axle simultaneously.

[0014] The electric motor includes a direct drive with stator and rotor.

[0015] The embodiments also relate in particular to the following features: Optionally, a section of the steering axle can function as a rotor. The rotor is advantageously arranged in extension of the steering axis. A section of the steering axle is advantageously designed as a rotor. The position of the joystick, e.g. center, left, right or any intermediate position, advantageously represents an angular displacement of the steerable wheels. The joystick advantageously remains in the last position when released. Optionally, the joystick returns to the center when released, which also returns the wheels to the straight-ahead position. The deflection of the joystick advantageously determines the desired rotation speed of the steerable wheels. The deflection of the joystick advantageously determines the desired angular deflection of the steerable wheels. After being released, the joystick is automatically moved to a position that corresponds to the angular deflection of the steerable wheels.

[0016] The input device is advantageously located on an armrest next to the driver's seat of the vehicle, wherein the armrest can be rotated together with the input device into an upper or lower position, wherein the armrest is equipped with a sensor which detects the lower position of the armrest, wherein this detection is reported to the control unit, which is subsequently activated in the auxiliary input mode and wherein the control unit is ready to process the control signals of the input device.

[0017] The sensor is advantageously configured to detect whether / that the armrest is not in the lower position, whereby the control unit is removed from the auxiliary input mode and is no longer ready to process the control signals.

[0018] The input device is advantageously equipped with a presence sensor that detects physical contact between the driver's hand and the input device, wherein the control unit is configured to ignore manual operation of the steering wheel if the presence sensor simultaneously detects no physical contact between the driver's hand and the input device.

[0019] The control unit is advantageously configured to ignore control signals from the input device when the steering wheel is operated manually.

[0020] The system advantageously comprises one or more sensors configured to collect environmental data from the following group: - visual information of the vehicle interior; - visual information of the driver in the vehicle; - biometric data of the driver in the vehicle; - Entering an authorization device to verify the driver's authorization to control the vehicle; - visual information of the vehicle's surroundings, whereby the detection of an object potentially impeding the safe operation of the vehicle results in steering control to avoid a collision with the object; - GPS data of the current vehicle location, whereby the vehicle is guided to a planned or desired location based on the GPS coordinates.

[0021] The joystick is advantageously equipped with a force feedback mechanism that provides haptic feedback to the joystick and assists the driver in moving the joystick to steer the vehicle in a preferred direction, for example, to follow a programmed route.

[0022] The system is advantageously designed for installation in a vehicle and connection to the vehicle's existing control and / or steering elements.

[0023] Summary: The invention can be summarized as a hybrid steering system for a vehicle, whereby the vehicle can be steered either by joystick or steering wheel. The joystick is electrically connected to a control unit. This unit drives an electric motor, which rotates the steering axle either based on the input signals sent by the joystick and generated by the driver pressing the joystick in the desired direction, or by the driver turning the steering wheel. For example, if a signal current is generated by the joystick to steer right, this is converted into a rotation of the electric motor, which rotates the steering axle (together with the steering wheel) clockwise until the signal current stops, e.g., when the joystick returns to its original position. SHORT DESCRIPTION OF THE CHARACTERS

[0024] The invention is described in more detail in the following drawing figures. Reference numbers not explicitly described in a particular drawing figure refer to the other drawing figures. They show: Fig. 1 shows a schematic side view of an example vehicle, e.g. a front loader, in which the invention can be implemented; Fig. 2 a perspective view of section A from Fig. 1; Fig. 3 shows a perspective view of a retrofittable kit or device package, the components of which together can provide the functionality according to the invention; DETAILED DESCRIPTION OF THE FIGURES

[0025] The invention will now be described in terms of the following aspects and embodiments with reference to the figures. To facilitate reading, a list of the reference numerals used is provided below, along with a brief description. 100 inventive system 101 manual input device (e.g. joystick) 102 Basis of the manual input device 101 103 buttons 110 Armrest 112 Armrest bracket 110 113 Holder for manual input device 101 115 Pivot point of the armrest 110 116 Adjustment knob for the position of the armrest 110 120 steering wheel 121 Rotary knob for steering wheel 120 122 steering axle 130 electric motor 150 control unit or control unit 151 power cables 152 Power supply cable to the electric motor 153 Joystick signal cable 200 vehicles 201 front wheel 202 rear wheel 203 Shovel 204 tilt cylinders 205 Driver's cab 206 Driver's seat

[0026] The present invention relates to a device or system for controlling the driving behavior of a vehicle with a steerable wheel that can pivot about a rotational axis to determine the vehicle's direction of travel. The device can be operated manually by the driver.

[0027] Fig. 1 shows a side view of an example vehicle 200, ie a loader, for which the invention 100 can be configured.

[0028] The illustrated vehicle 200 has front wheels 201, rear wheels 202, a bucket 203, and a tipping cylinder 204 for operating the bucket 203. A driver's cab 205 serves the driver to operate the vehicle 200.

[0029] Fig. Figure 2 shows a perspective view of section A according to Fig. 1. Section A shows an example of the interior of a loader 200 cab. A driver's seat 206 and a steering wheel 120 are provided. Some drivers prefer a rotary knob 121 on the steering wheel, which allows for more ergonomic operation. However, operating the vehicle often requires numerous turns, which is not considered ergonomic.

[0030] The invention provides the provision of the Fig. 3 explained device components. Fig. 3 shows a retrofit package of devices or system components that together form a system and can ensure the functionality of the system 100 according to the invention. The devices can be sold individually or as a package. Preferably, the package comprises a retrofit product that can be easily installed in a vehicle with existing steering. Some or all of the devices can be replaced by retrofit devices. For example, a conventional steering wheel can be replaced with a steering wheel 120 with an electric motor 130, or the electric motor 130 can be connected to an existing steering wheel. The armrest 110 can replace an existing armrest, be added as an additional armrest, or an existing armrest can be adapted for the attachment of a manual input device (hereinafter referred to as a joystick) 101.

[0031] Instead of installing the devices that are part of the invention as an aftermarket product, the invention can also be integrated into the vehicle during factory production. The devices can come from an original equipment manufacturer (OEM).

[0032] A further description of exemplary embodiments follows from Fig. 3. The joystick 101 is preferably connected to the armrest 110. The base 102 of the joystick 101 serves to hold the joystick 101 in position and to enable its movement in multiple directions. The base 102 also includes a device for connecting the joystick 101 to the armrest 110. This device may include the illustrated bracket 113. The armrest 110 is equipped with a bracket 112 that (preferably) pivotally connects the armrest 110 to the vehicle 200. The armrest may be pivotable about the pivot point 115, as shown in Fig.2, and locked by the adjustment knob 116. Although modification of an existing steering wheel is possible, a retrofit steering wheel 120 can be provided that is already equipped with an electric motor 130. The central steering axis is connected to the electric motor 130 via a steering axle. The steering axle can be formed as an extension of the rotor of the electric motor 130 or can represent an extension of this rotor.

[0033] When the joystick 101 is moved in one direction (which is considered normal joystick functionality), the generated signals are converted by an electronic circuit in the base 102 and sent to the control unit 150 via the joystick signal cable 153. The control unit 150 is configured as an interface between a power supply (such as a vehicle battery) and the electric motor 130. The control unit 150 is powered via the power cable 151. A power supply cable connects the control unit 150 to the electric motor 130.For example, when the joystick 101 is moved to the left, the control unit 150 receives a corresponding signal from the base 102 via the signal cable 153 and converts this signal into reverse electrical power, which is delivered to the electric motor 130 via the power supply cable 152, resulting in counterclockwise rotation of the rotor of the electric motor 130 and subsequent counterclockwise rotation of the steering wheel 130. The control unit 150 can be factory-configured with default settings or customized to the user's individual needs. An interface connected to the control unit 150 can also be configured to allow the user to adjust the settings in advance or on the fly to suit their needs.

[0034] For example, a setting may include the rotation of the steering wheel 130 being more or less aggressive in response to a movement of the joystick 101. A small deflection of the joystick 101 in one direction may result in a small rotation, while a large deflection may result in a faster rotation of the steering wheel 130. Other relationships between the movement of the joystick 101 and the electric motor 130 are also conceivable and configurable to a certain extent. From an ergonomic point of view in particular, fine-tuning this relationship is very important for the user, and the invention enables this to the maximum extent. The control unit 150 is preferably equipped with one or more fuses and a main switch for shutting down the entire system. An emergency stop switch may also be provided to shut down the system in an emergency.

[0035] For vehicles with invisible / difficult-to-see steerable wheels, such as a forklift truck, the problem arises when exiting, entering, and / or maneuvering that the position of the steerable wheels, i.e., the steering angle, is unclear. The joystick 101 provides no visual indication. There is a risk that the vehicle will make an unexpected turn when starting off, causing damage or an accident.

[0036] In most vehicles with joystick steering, the joystick is designed to return to the center position after being released. Unlike a conventional steering wheel, the position of the joystick does not indicate the position of the steerable wheels.

[0037] One way to determine the position of the wheels is to check them visually or, for example, to install and query a position indicator on the dashboard.

[0038] The invention solves this problem by establishing a logical relationship between the position of the joystick 101 and the position of the wheels.

[0039] The position of the joystick 101 (center, left, right, and intermediate positions) then represents the absolute rotation (angular displacement) of the steerable wheels. This allows the driver to easily determine the position of the steerable wheels.

[0040] There are two ways to influence the angle of the steerable wheels: 1. Joystick 101 remains in the last position when released, just like the position of the steerable wheels. 2. Joystick 101 returns to the center by default when released, which also returns the wheels to the straight-ahead position.

[0041] In both cases, the angle of joystick 101 represents the angle of the wheels. The joystick's end stops correspond to the wheel end stops. The center position of the joystick represents the straight-ahead position of the steerable wheels.

[0042] To ensure reliability, this system is first calibrated: The joystick's end stops are adjusted to the end stops of the steerable wheels. Recalibration can be performed if necessary while driving or steering.

[0043] Manual operation of the joystick can include one of the following two modes of rotation of the steerable wheels: Mode 1: The deflection of the joystick 101 determines the desired rotation speed of the steerable wheels. Mode 2: The deflection of the joystick 101 determines the desired position of the steerable wheels. The invention provides that the system can be switched between these modes at the factory and / or by the driver.

[0044] A visual indicator can be added to show the selected mode.

[0045] Other variants include the following: In mode 1 (deflection determines the rotation speed), joystick 101 assumes the position corresponding to the position of the steerable wheels after release. This gives the driver a visual indication of the position of the steerable wheels when exiting, entering, or stationary. The interaction between joystick 101 and the rotation of the steerable wheels can be software-controlled. The software can also be used to adjust how fast the steerable wheels rotate at which joystick position. A slow rotation speed with a large amount of travel can be advantageous for precise steering, for example, on a forklift. The joystick can be equipped with a force feedback mechanism that provides the driver with haptic feedback via the joystick, assisting them in moving the joystick to steer the vehicle in the desired direction. A planned route, for example, can be stored. Using GPS or other location services, the system can then monitor whether the driver is following the planned route. If the driver deviates from the planned route, the joystick provides haptic feedback in the correct direction. An electric motor can be integrated into the joystick to provide the haptic feedback.

[0046] It should be noted that the above embodiments illustrate and do not limit the invention. A person skilled in the art can devise many alternative embodiments without departing from the scope of the appended claims. The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those recited in the claim. The term "and / or" encompasses all combinations of one or more of the associated listed elements. The article "a" or "an" before an element does not exclude the presence of multiple such elements. The article "the" before an element does not exclude the presence of multiple such elements. In a system claim that lists multiple means, multiple of these means may be embodied by one and the same hardware.The mere fact that certain measures are listed in different dependent claims does not mean that a combination of those measures cannot be used to advantage. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2004 / 0039507 A1

[0006] JP 2000 / 318587 A

[0007] EP 0525817 A1

[0008]

Claims

[1] System for controlling the steering of a wheeled vehicle with one or more steerable wheels and mechanical steering, comprising: - a steering wheel for manual operation of the mechanical steering by the driver; - a steering axle connected to the steering wheel and rotatable by rotation of the steering wheel, the rotation of the steering axle being converted into a steering movement of the steerable wheels; - an electric motor for operating the mechanical steering; - a control unit for controlling the electric motor; - a manual input device, such as a joystick, to activate the control unit in auxiliary input mode; - wherein the input device is configured to transmit control signals to the control unit, wherein the control unit converts the control signals in the auxiliary input mode into steering commands for controlling the electric motor, characterized by , that - the electric motor comprises a direct drive with stator and rotor, wherein the rotor is arranged in extension of the steering axis, wherein the rotor is designed to rotate the steering wheel and the steering axis simultaneously. [2] System according to the preceding claim, characterized by that a section of the steering axle acts as a rotor. [3] System according to claim 1 or 2, characterized by that the rotor is arranged in extension of the steering axis. [4] System according to one of the preceding claims, characterized by that the position of the joystick, e.g. center, left, right or any intermediate position, represents an angular displacement of the steerable wheels. [5] System according to claim 4, characterized by that the joystick remains in the last position when released. [6] System according to claim 4, characterized bythat the joystick returns to the center when released, which also causes the wheels to return to the straight-ahead position. [7] System according to one of the preceding claims, characterized by that the deflection of the joystick determines the desired rotation speed of the steerable wheels. [8] System according to one of claims 1 to 7, characterized by that the deflection of the joystick determines the desired angular deflection of the steerable wheels. [9] System according to claim 8, characterized by that after being released, the joystick is automatically moved to a position that corresponds to the angular deflection of the steerable wheels. [10] System according to one of the preceding claims, characterized bythat the input device is located on an armrest next to the driver's seat of the vehicle, wherein the armrest can be rotated together with the input device into an upper or lower position, wherein the armrest is equipped with a sensor which detects the lower position of the armrest, wherein this detection is reported to the control unit, which is then activated in auxiliary input mode and wherein the control unit is ready to process the control signals of the input device. [11] System according to claim 10, characterized by that the sensor detects that the armrest is not in the lower position, whereby the control unit is removed from the auxiliary input mode and is no longer ready to process the control signals. [12] System according to one of the preceding claims, characterized bythat the input device is equipped with a presence sensor that detects physical contact between the driver's hand and the input device, wherein the control unit is configured to ignore manual operation of the steering wheel if, at the same time, the presence sensor does not detect physical contact between the driver's hand and the input device. [13] System according to one of the preceding claims, characterized by that the control unit is configured to ignore control signals from the input device when the steering wheel is operated manually. [14] System according to one of the preceding claims, characterized by that it includes one or more sensors configured to collect environmental data from the following group: - visual information of the vehicle interior; - visual information of the driver in the vehicle; - biometric data of the driver in the vehicle; - Entering an authorization device to verify the driver's authorization to control the vehicle; - visual information of the vehicle's surroundings, whereby the detection of an object potentially impeding the safe operation of the vehicle results in steering control to avoid a collision with the object; - GPS data of the current vehicle location, whereby the vehicle is guided to a planned or desired location based on the GPS coordinates. [15] System according to one of the preceding claims, characterized by that the joystick is equipped with a force feedback mechanism that provides haptic feedback to the joystick and assists the driver in moving the joystick to steer the vehicle in a preferred direction, for example, to follow a programmed route. [16] System according to one of the preceding claims, characterized bythat it is designed for installation in a vehicle and for connection to existing control and / or steering elements of the vehicle.

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