Method and device for controlling the speed of a vehicle

Abstract

A method and associated device for controlling the speed of a vehicle are proposed, wherein the vehicle has a device for requesting acceleration, a device for determining the instantaneous vehicle speed, and at least one environment sensing system for detecting objects in the vehicle's environment. and in which, by means of an evaluation device, a maximum speed is determined depending on the measured object distance when an object is detected in the future driving area of ​​the vehicle, and the torque request or acceleration request is only implemented by the vehicle's drive system if the current vehicle speed is below the determined maximum speed.

Description

[0001] The present invention relates to a method and an associated device for controlling the speed of a vehicle, wherein the vehicle has a device for requesting acceleration, a device for determining the current vehicle speed, and at least one environment detection system for detecting objects in the vehicle environment and in which, by means of an evaluation device, upon detection of an object in the future driving range of the vehicle, a maximum speed is determined as a function of the measured object distance and the torque request or acceleration request is only implemented by the drive system of the vehicle if the current vehicle speed is below the determined maximum speed. State of the art

[0002] DE 10 2020 211 539 A1 discloses a method and a driver assistance system for a single-track or multi-track motor vehicle, in which an object detection sensor detects objects traveling ahead of the vehicle and the speed of the vehicle is controlled by means of a cruise control such that upon detection of a preceding object, a predetermined distance of the vehicle from the preceding object is set and the driver can change the distance of the vehicle from the preceding object by operating the accelerator pedal or a rotary handle while following behind the preceding object. When the driver assistance system is deactivated, at least one or more vehicle systems are monitored and, upon operation of the at least one or more vehicle systems, a conclusion is drawn about the degree of distraction of the driver and, depending on the degree of distraction, the driver assistance system is automatically activated. Disclosure of the invention

[0003] The core of the present invention is to provide a method and device that prevents accidents, particularly at low speeds, by only transmitting an acceleration request to the drive system when the vehicle speed is sufficiently low or the distance to an object is sufficiently large to allow the vehicle to decelerate without collision. This advantageously prevents many major accidents that occur during maneuvering and parking due to confusion between the accelerator pedal and the brake pedal.

[0004] According to the invention, this is achieved by the features of the independent claims. Advantageous further developments and refinements emerge from the subclaims.

[0005] Advantageously, the acceleration request device is a manual input device, in particular an accelerator pedal. The accelerator pedal, often also called the gas pedal, is a device in vehicles through which the driver controls acceleration and thus speed. The angle of the accelerator pedal corresponds to an acceleration request or a torque request from the drive system. Using the driving dynamics equation, each of the two values ​​can be converted into the other.

[0006] Furthermore, it is advantageous that the acceleration request is a torque request. This allows the system according to the invention to implement only an acceleration request, only a torque request, and, if the road gradient, vehicle weight, and internal drive resistance are known, a combination of both values ​​can be implemented.

[0007] A significant advantage is that if the distance between the object and the environment sensor is small, the vehicle can be accelerated by pressing the accelerator pedal, but only to such an extent that the speed does not become too high and the vehicle does not accidentally collide with the object, causing serious damage.

[0008] Advantageously, the environment detection system consists of one or more sensors and detects objects in at least the surrounding area in the direction of travel of the vehicle. Vehicles today are equipped with a large number of sensors, usually of different sensor types. Depending on the application and the associated speed and distance ranges to be measured, different sensor types (ultrasound, radar, video, lidar, etc.) can be used individually or possibly even in combination. Ultrasonic sensors are particularly suitable for distance measurements at shorter distances, while radar sensors are particularly suitable for longer distances. However, implementation using (stereo) video systems and / or lidar systems is also conceivable.

[0009] Furthermore, it is advantageous for the environment detection system to provide the distance of the detected object from the vehicle. The environment detection system, with its sensor(s), should be able to not only detect whether an object is present within the sensor detection range or not, but also determine the distance between the environment sensors and the object. Alternatively, or in combination, triangulation can be used to determine the relative distance of the object from the vehicle, thus also calculating the shortest distance between the vehicle and the object.

[0010] Furthermore, it is advantageous that the maximum speed (vmax) is stored in a table in memory. This allows each object distance from the vehicle to be assigned a determined maximum speed, taking into account the maximum vehicle deceleration. This can advantageously be stored in a memory in the evaluation unit, in a central vehicle database, or in a cloud database in which the determined maximum speeds are stored and adjusted accordingly in response to changing local weather conditions.

[0011] Alternatively, it is advantageous that the maximum speed (vmax) is continuously calculated from the object distance and maximum deceleration capability of the vehicle in the evaluation device and this value is further processed.

[0012] Furthermore, it is advantageous that the maximum speed (vmax) indicates the speed at which the vehicle, with maximum deceleration capability, can just be brought to a standstill in front of the object without a collision occurring. For this purpose, the maximum speed is determined as the value at which the measured distance between the object and the environment sensors can just be brought to a standstill at a given maximum vehicle deceleration.

[0013] Furthermore, it is advantageous that the function is deactivated above a predetermined vehicle speed (vThreshold). Particularly in the case where the function is to be used only in the lower speed range to avoid damage when maneuvering and parking / returning the vehicle, it is advantageous to specify a threshold speed above which the function according to the invention is automatically deactivated.

[0014] Of particular importance is the implementation of the method according to the invention in the form of a control element provided for a control unit of a parking aid or a driver assistance function of a motor vehicle. A program is stored on the control element that can be executed on a computing device, in particular on a microprocessor or signal processor, and is suitable for carrying out the method according to the invention. In this case, the invention is implemented by a program stored on the control element, so that this control element provided with the program represents the invention in the same way as the method for which the program is suitable. In particular, an electrical storage medium, for example a read-only memory, can be used as the control element.

[0015] The method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit.

[0016] The approach presented here further creates a variable speed limiter that is designed to carry out, control, or implement the steps of a variant of the method presented here in corresponding facilities.

[0017] The distance controller can be an electrical device with at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, and at least one interface and / or a communication interface for reading in or outputting data embedded in a communication protocol. The computing unit can be, for example, a signal processor, a so-called system ASIC, or a microcontroller for processing sensor signals and outputting data signals depending on the sensor signals. The memory unit can be, for example, a flash memory, an EPROM, or a magnetic storage unit. The interface can be designed as a sensor interface for reading in the sensor signals from a sensor and / or as an actuator interface for outputting the data signals and / or control signals to an actuator.The communication interface can be configured to read or output data wirelessly and / or via a wired connection. The interfaces can also be software modules, which are present, for example, on a microcontroller alongside other software modules.

[0018] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular when the program product or program is executed on a computer, a programmable controller or a similar device.

[0019] It should be noted that some of the possible features and advantages of the invention are described herein with reference to various embodiments, such as a method for controlling a distance and a distance controller. One skilled in the art will recognize that the features can be combined, adapted, or interchanged as appropriate to achieve further embodiments of the invention. short description of the drawings

[0020] In the following, exemplary embodiments of the invention are explained with reference to drawings. Fig. 1 a schematic plan view of an exemplary driving situation to explain the method according to the invention, Fig. 2 a schematic block diagram of an exemplary embodiment of the device according to the invention and Fig. 3 a schematic flow diagram of an exemplary embodiment of the method according to the invention. Embodiments of the invention

[0021] In Fig. Figure 1 shows a traffic situation in which the user's own vehicle 1 is depicted. A rectangle 2 is shown in front of the user's own vehicle 1, representing any object 2. This object can be a stationary, immobile object such as a house wall, a pillar, or a wall in a parking garage, or a stationary, mobile object, such as a parked vehicle. As long as the object is moving very slowly, it can even be a moving object.

[0022] An environment sensor system 3 is mounted on the front of the vehicle 1. This environment detection system 3 consists of one or more sensors that are mounted on the front of the vehicle, the rear of the vehicle, the corners of the vehicle, and / or the vehicle itself. They detect the vehicle's surroundings 4 using ultrasonic signals, radar signals, laser signals, or video recordings, and determine objects 2 and their distance from the vehicle 1. Each sensor of the environment detection system 3 has a sensor detection range 4 that can detect objects 2 within a defined range. Advantageously, several sensors can be mounted such that the sensor detection ranges 4 of the individual sensors 3 complement each other.

[0023] The distance values ​​determined by the environmental sensors 3 are forwarded as sensor signals 5 to an evaluation device 6 via a line, preferably a bus system.

[0024] The evaluation device 6 can be designed as a standalone control unit that only implements the function according to the invention. Alternatively, the evaluation device 6 can also be designed as a zone control unit, in which one control unit is provided for all functions implemented in a specific area (front area, rear area, interior, etc.) of a vehicle, and the functions share the same hardware resources of the control unit. It is also possible to provide the control unit 6 as the central control unit of a vehicle, in which, for example, all driver assistance functions are bundled.

[0025] Furthermore, the evaluation device 6 can be integrated into a sensor, so that the evaluation takes place directly at the sensor and a so-called “smart sensor” is created.

[0026] In addition to the sensor signal 5, at least one vehicle speed signal 16, which represents the speed v currently traveled by the vehicle 1, is fed to the evaluation device 6 as further input signals. This signal can advantageously be read directly from a CAN bus used in the vehicle. This vehicle speed signal (v) 16 originates from a vehicle speed sensor 15, which is determined, for example, from the individual wheel speeds or is calculated from a satellite navigation signal (e.g., a GPS signal). Alternatively, this vehicle speed signal (v) 16 can also originate from an environmental sensor, which determines the current vehicle speed v based on the relative speed of stationary objects.

[0027] Furthermore, an acceleration request signal 18 is supplied to the evaluation device 6, which, for example, originates from a signal from an accelerator pedal and can alternatively also be designed as a torque request.

[0028] According to the invention, the evaluation device determines whether the acceleration request signal or the torque request signal may be output to the control of the drive 8 and, if necessary, output as output signal 7 to the control of the drive 8 of the vehicle. There, the acceleration request or the torque request is converted into drive power and transmitted via the drive wheels 9, which are in Fig. 1 are shown as an example as the rear wheels 9 of the vehicle 1, and the vehicle is accelerated if necessary.

[0029] In Fig. Figure 2 shows an exemplary embodiment of the device according to the invention. The evaluation device 6 can be seen, which has an input circuit 12 via which input signals 5, 16, 18 can be fed to the evaluation device 6. According to the invention, at least one sensor signal 5 from an environment detection system 3, a vehicle speed signal 16 from a vehicle speed sensor 18, and a torque request 18 or an acceleration request 18, which originates, for example, from a driver-operated accelerator pedal, are provided as input signals.

[0030] The input signals supplied to the input circuit 12 of the evaluation device 6 are forwarded to a calculation device 20 via a data exchange device 19, which can be implemented, for example, as an internal bus system of the evaluation device 6. In the calculation device, which can be implemented, for example, as a microprocessor, a signal processor, or an application-specific integrated circuit (ASIC), output signals are calculated and determined using the method according to the invention, which runs, for example, in software on the calculation device. The determined output signals are forwarded from the calculation device 20 via the data exchange system 19 to the output circuit 21, where they are output as output signals 7 from the evaluation device 6 and output to downstream devices and actuators.

[0031] At least one acceleration signal 7 for the drive 8 is provided as the output signal 7 output by the output circuit 21. This signal outputs a torque request or an acceleration request to a power-determining actuator 23 of the drive 8. This power-determining actuator 23 can be, for example, an electrically controlled throttle valve or a fuel metering device in the form of a fuel injector for an internal combustion engine. Alternatively or additionally, the power-determining actuator 23 can also be a power semiconductor that doses the current for an electric drive and thus regulates the output drive power.

[0032] If the environment sensor system 3 detects an object 2 in the environment of the vehicle 1 that extends at least partially into the detection range 4 of the environment detection system 3, the distance between the sensor system 3 and the object 2 is determined. If the object is detected by multiple sensors 3, the minimum distance between the vehicle 1 and the object 2 can be calculated from the distances of the individual sensors 3 to the object 2 by means of triangulation and trilateration and by knowing the installation locations of the sensors 3 on the vehicle 1. This distance value is sent to the evaluation device 6 as a sensor signal 5. At the same time, the evaluation device 6 receives a vehicle speed signal 16 that represents the current speed v of the vehicle 1. Furthermore, the evaluation device 6 receives an acceleration request signal or a torque request signal from an accelerator pedal as input signal 18.

[0033] If the distance between the vehicle 1 and the object is small, for example because the vehicle is currently being maneuvered in a parking garage or on a parking lot and is being maneuvered into a parking space in which the distances to other objects such as concrete walls, barriers or other vehicles are small, the maximum deceleration capacity of the vehicle stored in the evaluation device 6 and the current vehicle speed v are used to determine whether the vehicle 1 can be braked before a collision with an object 2. If the current speed is so low that the vehicle 1 can be braked in time, the acceleration request, which is specified by the acceleration request device 128 or the torque request 18 by the driver, is output as output signal 7 by the evaluation device 6 and implemented by the power-determining actuator 23 of the drive 8.

[0034] If the driver confuses the accelerator and brake pedals, or accidentally presses the accelerator pedal too hard, the vehicle accelerates. This acceleration increases the vehicle speed v to the point where the distance between vehicle 1 and object 2 is so small, or the vehicle speed is so high, that the vehicle can no longer stop in front of object 2 without colliding. From this point onward, the acceleration request 7 or the torque request 7 is no longer output to the power-determining actuator 23 of the drive 8. This can be done by not outputting an output signal 7, or by setting an output signal 7 of the evaluation device 6 to zero, regardless of the input value of the acceleration request signal 18 in the evaluation device 6.

[0035] From this point onwards, vehicle 1 can no longer be accelerated by the driver, so that a possible collision between vehicle 1 and object 2 would only be very minor, but major damage or even a vehicle falling from a higher level of a parking garage would be impossible. In order to avoid unexpected restrictions on vehicle acceleration during normal driving, the driving function described can be designed so that it only remains activated up to a threshold speed and is therefore only active at normal shunting and maneuvering speeds. If the vehicle speed v exceeds the threshold speed, which is the case during normal driving on roads, country roads or when driving by car, the function is deactivated in order to avoid unexpected acceleration restrictions, for example when overtaking.

[0036] This threshold speed can, for example, be in the range between 10 km / h and 20 km / h, in particular 15 km / h.

[0037] If the driver accidentally presses the accelerator pedal instead of the brake pedal while parking, the vehicle will accelerate 1. If the driver is startled and presses the accelerator pedal even harder, thinking they are pressing the brake pedal, the vehicle will no longer accelerate once the calculated maximum vehicle speed vmax is reached. This does not always prevent a collision completely, but it does cause a collision at a low speed, so only minor damage can occur but fatal accidents are avoided.

[0038] In Fig.Figure 3 shows a schematic flow diagram intended to illustrate the functionality of the method according to the invention. The method begins in step 26 with activating the vehicle, for example, by activating the "terminal 15" contact or by activating the driver assistance function.

[0039] In the subsequent step 27, the method continues in step 28, in which an acceleration request 18 or a torque request 18 is read in by the driver. This is requested, for example, by an accelerator pedal, but can also be requested by another driver assistance system or safety system. This request signal is read into the evaluation device 6 as an acceleration request signal 18.

[0040] In the following step 29, a vehicle speed signal 16 from a vehicle speed sensor 15 is read into the input circuit 12 of the evaluation device 6.

[0041] In the following step 30, the input signal is processed, and a maximum speed vmax is determined, which represents a maximum permissible speed at which vehicle 1 can still stop in front of object 2. This can be done by retrieving a table stored in memory, for example, by storing a maximum deceleration capability of vehicle 1 in the low speed range in the evaluation device 6. Alternatively, it is also possible to calculate this maximum speed vmax, for example, from the assumption of uniform deceleration with a maximum deceleration capability and the deceleration distance corresponding to the remaining distance between vehicle 1 and object 2.

[0042] After determining the maximum speed vmax, the following step 31 checks whether the vehicle speed v is greater than the maximum speed vmax determined in step 30. If the condition in step 31 is not met, i.e., if the vehicle speed v is less than the maximum vehicle speed vmax, step 31 branches to "no" and continues in step 32, in which the evaluation device 6 forwards the acceleration request 7 or the torque request 7 to the control of the drive 8 and the vehicle accelerates further.

[0043] After step 32, the process continues in step 27 by repeating the process steps.

[0044] If the decision in step 31 resulted in the condition being met, i.e., the vehicle speed v is greater than or equal to the maximum vehicle speed vmax, step 31 branches to "yes" and continues in step 33. In step 32, the evaluation device 6 prevents the acceleration request 7 or the torque request 7 from being passed on to the control of the drive 8, for example, by setting the acceleration request 7 or the torque request 7 to zero or by not sending any request at all. As a result, the power-determining actuator 23 of the drive 8 no longer accelerates the vehicle 1, but instead continues rolling at the existing speed without acceleration. The driver can now depress the brake pedal or at least has more time to recognize the situation than if the vehicle were to continue accelerating to its maximum. After step 33, the process is run through again in step 27.

[0045] Optionally, a further method step can be provided between steps 26 and 27 of the figure, in which the instantaneous vehicle speed v of the vehicle speed sensor 15 is compared with a threshold speed vThreshold. The threshold speed vThreshold is a limit speed above which the function according to the invention is no longer active, but always passes the acceleration request 18 or the torque request 218 on to the drive via the output signal 7 of the evaluation device 6. This would mean that the function would only be active during maneuvering and parking, as well as during slow driving within built-up areas, and implausible acceleration limitations on fast roads would be prevented. For this purpose, the limit speed vThreshold would have to be set in the range between 15 km / h and 30 km / h, preferably in the speed range around 20 km / h. 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 2020 211 539 A1

[0002]

Claims

[1] Method for controlling the speed of a vehicle (1), wherein an evaluation device (6) an acceleration request signal (7) is fed to an acceleration request device (17), a vehicle speed signal (16) of a vehicle speed sensor (15) is supplied, and at least one sensor signal (5) of an environment detection system (3) for detecting objects (2) in the vehicle environment (4), characterized by , that by means of the evaluation device (6) upon detection of an object (2) in the future driving range (4) of the vehicle (1), a maximum speed (vmax) is determined as a function of the measured object distance and the acceleration request is only implemented by the drive system (8) of the vehicle (1) if the current vehicle speed (v) is below the determined maximum speed (vmax). [2] Method according to claim 1, characterized by that the device for requesting acceleration (17) is a manual input device, in particular an accelerator pedal. [3] Method according to claim 1 or 2, characterized by that the acceleration request (16, 7) is a torque request. [4] Method according to one of the preceding claims, characterized by that the environment detection system (3) consists of one or more sensors and detects objects (2) in at least the surrounding area (4) in the direction of travel of the vehicle (1). [5] Method according to one of the preceding claims, characterized by that the plurality of sensors (3) consist of different types of sensors, in particular radar sensors, ultrasonic sensors, video sensors, lidar sensors or any combination thereof. [6] Method according to one of the preceding claims, characterized bythat the environment detection system (3) provides the distance of the detected object to the vehicle (1). [7] Method according to one of the preceding claims, characterized by that the maximum speed (vmax) is stored in a table in a memory, in particular a memory in the evaluation device (6). [8] Method according to one of the preceding claims 1 to 7, characterized by that the maximum speed (vmax) is calculated from the object distance and the maximum deceleration capability of the vehicle (1). [9] Method according to claim 8, characterized by that the maximum speed (vmax) indicates the speed at which the vehicle (1) with maximum deceleration capability can just be braked to a standstill in front of the object (2) without a collision occurring. [10] Method according to one of the preceding claims, characterized bythat the function is deactivated above a specified vehicle speed (vThreshold). [11] Device for controlling the speed of a vehicle (1), wherein the vehicle (1) a device for requesting acceleration (17), a device for determining the current vehicle speed (15), and at least one environment detection system (3) for detecting objects (2) in the vehicle environment (4) characterized by , that by means of an evaluation device (6) upon detection of an object (2) in the future driving range (4) of the vehicle (1), a maximum speed (vmax) is determined as a function of the measured object distance and the acceleration request is only implemented by a drive system (8) of the vehicle (1) if the current vehicle speed (v) is below the determined maximum speed (vmax). [12] Computer program product which is designed to execute, implement and / or control the method according to one of claims 1 to 10. [13] A machine-readable storage medium on which the computer program product according to claim 12 is stored.

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