Method for operating a vehicle by means of a multi-actuator control

Abstract

Method for operating a vehicle (10, 30, 40) by means of a multi-actuator control, in which data from the environment of the vehicle (10, 30, 40) are determined using at least one environment sensor and, taking into account the multi-actuator control of the vehicle (10, 30, 40), at least one trajectory is selected which satisfies the collision-free requirement.

Description

[0001] The invention relates to a method for operating a vehicle by means of a multi-actuator control and an arrangement for carrying out the method. State of the art

[0002] In traditional vehicle architectures, different actuators, such as the steering, brakes, active chassis, or powertrain, are controlled separately. The driver's actuation of an actuator only directly affects that individual actuator. Interactions between the actuators are either not considered at all or only minimally considered.

[0003] Multi-actuator control allows the actions of the various actuators to be coordinated and adapted to the situation. For example, the driver's request to change direction, triggered by a steering wheel movement, can be implemented not only by controlling the steering actuator(s), but also by additional braking intervention on individual wheels. This enables a multitude of new functions that, among other things, improve driving dynamics in extreme situations, increase driving comfort, or support economical driving. The multi-actuator control can be implemented centrally or distributed or decentralized.

[0004] In the current state of the art, the behavior of the multi-actuator control depends on a multitude of parameters, such as speed, acceleration or road surface conditions.

[0005] The publication DE 10 2012 203 228 A1 describes a method for avoiding or mitigating the consequences of collisions between a motor vehicle and an obstacle in the immediate lateral area of ​​the motor vehicle. The method involves detecting an obstacle in the immediate lateral area of ​​the motor vehicle, determining the vehicle's path of travel, determining a collision risk, taking the path of travel and the position of the obstacle into account, and adjusting the steering angle of the rear wheels of the motor vehicle. This allows the vehicle to avoid the obstacle. Disclosure of the invention

[0006] Against this background, a method having the features of claim 1 and an arrangement according to claim 12 are presented. Embodiments emerge from the dependent claims and from the description.

[0007] A method for operating a vehicle, in particular a motor vehicle, by means of a multi-actuator control is presented, in which data from the environment of the vehicle are determined using at least one environment sensor and, with the inclusion of a multi-actuator control of the vehicle, at least one trajectory is selected which satisfies collision freedom.

[0008] Multi-actuator control means that at least two actuators of the vehicle, in particular from different subsystems of the vehicle, such as a steering actuator of a steering system and a brake actuator of a brake, are addressed simultaneously or in a coordinated manner.

[0009] This is the first time that the possibility of operating the multi-actuator control with the aim of ensuring collision-free operation with the environment is used.

[0010] A trajectory that satisfies collision freedom is a trajectory that describes a path or a driving path of the vehicle that does not entail a collision with any of the detected obstacles.

[0011] The data from at least one environmental sensor describes the environment or surroundings of the vehicle and thus also the position, dimensions and, if applicable, the nature of obstacles in this environment.

[0012] Thus, after detecting an obstacle in the environment, the multi-actuator control can be used to obtain a list of all possible trajectories and, from these, to identify the one or more trajectories that actually enable collision-free travel. This means that a comparison is made between the all possible trajectories and the collision-free trajectories.

[0013] Alternatively, at least one collision-free trajectory is first determined and then it is checked, taking into account the multi-actuator control, whether and if so how this at least one trajectory can be implemented, ie how the multi-actuator control must be controlled to ensure collision-free travel.

[0014] In one embodiment, the method is carried out in conjunction with a rear axle steering (HAL).

[0015] A HAL allows you to directly influence the vehicle's dynamics by turning the rear wheels. This type of HAL makes it possible to reduce the turning circle, particularly in tight curves or during tight maneuvers and maneuvering. At higher speeds, a HAL can increase driving stability and thus safety, especially during evasive maneuvers and lane changes, by turning the rear wheels in the direction of the front wheels.

[0016] To execute steering commands on the rear axle, hydraulic or electromechanical actuators can be used, as on the front axle.

[0017] Vehicles with HAL are usually designed so that the rear axle turns in the opposite direction to the front axle at low speeds and in the same direction as the front axle at higher speeds. In the former case, a smaller turning circle is achieved, although the position of the turning circle changes. Compared to a vehicle without HAL or a vehicle with HAL with the same direction of steering, the rear swings out. This is not advantageous in all situations. It can be a disadvantage, particularly in confined spaces or when parking. In commercial vehicles, this disadvantage can be particularly noticeable on tight construction sites.

[0018] It is important that a multi-actuator control is used with the focus on implementing spatially optimized trajectories and that, in the case of a HAL, the steering direction, which is usually speed-dependent, can be adapted situationally and automatically.

[0019] The method is particularly suitable for use in confined spaces and at low speeds, e.g. in an underground car park, on a construction site, etc.

[0020] The method is designed to calculate a trajectory based on the vehicle's surroundings within the framework of multi-actuator control, which avoids collisions with the surroundings. For this purpose, an image of the surroundings is determined or calculated from data from environmental sensors, such as ultrasonic sensors, radar sensors, etc., and compared with the theoretically possible trajectories using different actuators.

[0021] Trajectories that avoid a collision with the surroundings, i.e., collision-free trajectories, can be given priority over trajectories with a collision with the surroundings in a ranking. If several trajectories meet the collision-free criteria, additional factors, such as tire wear or a steering or handling feel that is as familiar as possible, can be taken into account in the ranking.

[0022] The trajectory resulting from the ranking can be implemented automatically or provided to the driver from a selection. This can be done, for example, via a display, such as a bird's-eye view. It can also be executed by an assistance function, such as a parking assistant, or an autonomous driving function. Manual activation from a selection of trajectories is also possible, for example, via a navigation system menu.

[0023] The presented arrangement serves to carry out the described method and is implemented, for example, in hardware and / or software. The arrangement can also be integrated into a vehicle control unit or be designed as such. Furthermore, the arrangement can be incorporated as a component in a multi-actuator control system.

[0024] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

[0025] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention. Short description of the drawings Fig. Figure 1 shows a schematic representation of vehicles in different driving situations. Fig. 2 shows a schematic representation of a vehicle with an embodiment of the presented arrangement for carrying out the described method. Fig. 3 shows a flow chart of a possible sequence of the presented procedure. Embodiments of the invention

[0026] The invention is illustrated schematically in the drawings using embodiments and is described in detail below with reference to the drawings.

[0027] Fig. Figure 1 shows vehicles with rear-axle steering in different driving situations. On the left, a vehicle 10 is shown, which has two articulated front wheels 12 and two articulated rear wheels 14 with a rear-axle steering system 16. The articulated rear wheels 14 are turned or steered in the opposite direction to the front wheels 12, as is common at low speeds.

[0028] The vehicle 10 is parked close to an obstacle 20, in this case a wall. The illustration illustrates that driving with the front wheels 12 and rear wheels 14 steered in opposite directions will result in a collision 22 due to a pivoting movement of the rear of the vehicle 10. If the obstacle 20 is detected, the rear-axle steering 16 can be controlled in such a way that this collision 22 can be avoided. This is illustrated on the right side of the illustration.

[0029] Fig. 1 shows on the top right side a vehicle 30 with articulated front wheels 32 and articulated rear wheels 34 of a rear axle steering 36. This vehicle 30 is close to an obstacle 38. By steering the rear wheels 34 in the same direction as the front wheels 32, a collision can be avoided.

[0030] On the bottom right, another vehicle 40 with articulated front wheels 42 and articulated rear wheels 44 of a rear-axle steering system 46 is shown, which is positioned close to the obstacle 38. A neutral position of the articulated rear wheels 44 of the rear-axle steering system 46 can also prevent the rear of the vehicle 40 from swinging out and thus a collision.

[0031] Fig. Figure 2 shows a schematic, highly simplified representation of a vehicle 50 with a rear-axle steering system 52, which is to be controlled within a multi-actuator control system 54. Furthermore, environmental sensors 58 are provided, which can detect obstacles in the environment of the vehicle 50 and can forward corresponding data to an arrangement 56 for implementing the method. This arrangement 56 can directly output a control signal to the multi-actuator control system 54 for controlling the rear-axle steering system 52. Alternatively, information about a selected trajectory can also be initially displayed to the driver on a display 60.

[0032] An evaluation unit 62 is provided in the arrangement 56, which is configured to evaluate the incoming data, determine or calculate a control signal for the actuator control 54 based on the evaluation, and send this control signal to the multi-actuator control 54. The evaluation unit 62 can also evaluate data from the multi-actuator control 54, possibly relating to possible trajectories.

[0033] Fig. Figure 3 illustrates an embodiment of the presented method in a flowchart. In a first step 80, an obstacle is detected using an environmental sensor. Collision-free trajectories are then determined in a step 82. These are compared with possible trajectories in a step 84. These are trajectories that the vehicle can actually take due to the action of the multi-actuator control.

[0034] This comparison results in a selected trajectory, which is implemented in step 86 by controlling the multi-actuator control. The steering actuators assigned to the rear-axle steering and, if applicable, additional steering actuators are controlled in such a way that collision-free driving is ensured.

[0035] An environment-sensitive multi-actuator control can in particular mean that a HAL is not turned in the opposite direction but in the same direction even at low speeds, such as when parking, or that a steering operation can be carried out completely without the involvement of the HAL.

[0036] Furthermore, in addition to modifying the control of a HAL, it is possible to selectively drive or brake individual wheels, thus providing smaller turning circles or alternative, collision-free trajectories depending on the situation. Even functions that would be unsuitable as primary steering functions, for example, due to severe tire wear or unfamiliar handling, can be activated briefly in this way, enabling enhanced maneuverability at the limits of the vehicle's performance.

[0037] In vehicles with wheel hub motors, as an extreme case, a turn on the spot, i.e. track control, can be automatically activated or suggested for activation under tight turning conditions.

[0038] The presented method, at least in some of its forms, has a number of advantages. These include: Expanding maneuverability in confined spaces is possible. For existing systems, this can be implemented without additional hardware and solely as a software function.

[0039] The presented method is applicable to all vehicles with a multi-actuator control for steering functions, especially to vehicles with rear-axle steering. 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] DE 10 2012 203 228 A1

[0005]

Claims

[1] Method for operating a vehicle (10, 30, 40, 50) by means of a multi-actuator control (54), in which data from the environment of the vehicle (10, 30, 40, 50) are determined using at least one environment sensor (58) and, taking into account the multi-actuator control (54) of the vehicle (10, 30, 40, 50), at least one trajectory is selected which satisfies the collision-free requirement. [2] Method according to claim 1, which is used in conjunction with a rear axle steering system (16, 36, 46, 52). [3] Method according to claim 1 or 2, in which a ranking of trajectories which satisfy collision freedom is determined, from which a trajectory is selected. [4] Method according to one of claims 1 to 3, wherein the selected trajectory is proposed to the driver of the vehicle (10, 30, 40, 50). [5] Method according to claim 4, wherein the selected trajectory is displayed to the driver on a display (60). [6] Method according to claim 4 or 5, wherein, after confirmation by the driver, the multi-actuator control (54) is controlled such that the selected trajectory is implemented. [7] Method according to one of claims 1 to 3, wherein the selected trajectory is implemented directly by controlling the multi-actuator control (54). [8] Method according to claim 6 or 7, wherein the selected trajectory is implemented with the aid of a driver assistance function. [9] Method according to one of claims 1 to 8, wherein tire wear is taken into account when selecting the trajectory. [10] Method according to one of claims 1 to 9, wherein the steering feel associated with the trajectory is taken into account when selecting the trajectory. [11] Method according to one of claims 1 to 10, which is used for a caterpillar control. [12] Arrangement for operating a vehicle by means of a multi-actuator control (54), wherein the arrangement (56) has an evaluation unit (62) which is designed to carry out a method according to one of claims 1 to 9.

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