Method for warning a driver of a vehicle combination and electric drive system for the autonomous propulsion of a trailer vehicle of a vehicle combination

Abstract

The invention relates to a method for warning the driver of a vehicle combination (1), in which a warning message is issued when a fault (FF) is detected in a trailer vehicle (3) of the vehicle combination (1). In a method that ensures the driver of the vehicle combination (1) is informed promptly and reliably at all times about the occurrence of a fault situation in the trailer vehicle, the trailer vehicle (3) generates a warning message as haptic feedback for the driver from a braking function of the trailer vehicle (3) while the vehicle combination (1) is in motion.

Description

The invention relates to a method for warning a driver of a vehicle combination, in which a warning message is output if a fault is detected on a trailer vehicle of the vehicle combination, and to an electric drive system for autonomous drive of a trailer vehicle of a vehicle combination.DE 10 2013 222 898 A1 describes a method for displaying warning messages of vehicle tires of a truck trailer. If a tire problem is detected on the truck trailer, an error message is transmitted to the towing vehicle, where this is displayed to the driver by a modeled warning light signal.US 2011 / 80282 A1 discloses a method for vehicle monitoring in which one or more safety systems of a vehicle are monitored with regard to a safety problem. If such a security problem occurs, error information is transmitted to an operating device, such as a smartphone or a mobile radio telephone, by means of wireless communication paths.U.S. Pat. No. 4,145,682 discloses a dump truck in which a dangerous tilting position of a dump truck is indicated to a vehicle operator via a warning lamp. The warning lamp is blinked via a relay.According to FR 2261904 A, a relay circuit is known which generates control signals for warning lamps to cause them to blink. These flashing warning lamps indicate to a driver of a vehicle that a fault has been detected on a trailer of the vehicle.It is an object of the invention to specify a method for warning a driver of a vehicle combination, which ensures that the driver of the vehicle combination is informed promptly and reliably about the occurrence of a fault situation in the trailer vehicle.This object is achieved by a method according to claim 1. Thereafter, in the method for warning a driver of a vehicle combination during a journey of the vehicle combination, a warning message is issued if a fault is detected on a trailer vehicle of the vehicle combination. The warning message is generated by the trailer vehicle during the travel of the vehicle combination from a braking function of the trailer vehicle as haptic feedback for the driver.The object is also achieved by an electric drive system for autonomous drive of a trailer vehicle of a vehicle combination, comprising an electric drive unit which is coupled to a brake control unit. The electric drive system outputs brake signals to the wheels of the trailer vehicle via a brake modulator. The brake control unit is designed to generate a haptic warning message as feedback to the driver from the braking function of the trailer vehicle in the event of a fault.This has the advantage that warning messages from the drive function, in particular the brake function, of the trailer vehicle are communicated reliably to the driver, which is typically the driver of a towing vehicle of the towing vehicle combination. The communication with the driver takes place in parallel or alternatively for the use of displays in the towing vehicle. The driver can perceive a clearly changed driving behavior of the vehicle trailer by the braking automatically initiated by the trailer vehicle, without the traffic safety being reduced. This prevents safety gaps due to unavailable fault warning information. The driver's attention is thus always directed to the current traffic situation. The fault warning reaches the driver in the towing vehicle even if any external warning lights on the trailer vehicle that may be present are covered during cornering or turning processes and thus get for the driver from the field of view of the rearview mirror. This also applies if the external warning lights are impaired in their functioning by external influences, such as dirt or sun visor influence. A reliable warning of the driver is also provided if the driver cannot look at the instrument panel because of the current traffic situation.The method can be used independently of available interfaces between the towing vehicle and the trailer vehicle in the case of a wide variety of towing vehicle-trailer vehicle combinations.In one embodiment, the haptic feedback is generated by varying braking interventions generated by the braking system of the trailer vehicle. These braking interventions can vary both in time and / or in their intensity and can be set as a function of a safety-critical situation which is caused by the detected error. The braking intervention can be effected by intermittent short braking events or braking pulses, such as, for example, "sotter braking", in which short jerk-like brake actuations are realized. The individual brake pulses are selected to be sufficiently short to meet the overall safety concept of the vehicle combination.In a further embodiment, the short brake pulses are interrupted by at least one short drive pulse. This increases the haptic effect acting on the driver.In a further embodiment, the short brake pulses are interrupted when the driver actuates a brake in the towing vehicle. This ensures that braking initiated by the driver overrums the initiation of the short brake pulses and the driving behavior of the vehicle combination is determined by the driver.In a further embodiment, the haptic feedback is generated by braking the trailer vehicle to a restricted predefined speed. Such permanent braking ensures, in addition to the warning of the driver, that the vehicle combination can, for example, still reach the nearest workshop if he complies with his safety concept.In a further embodiment, brake lights of the trailer vehicle are activated as a warning signal. In addition, brake lights of the towing vehicle can also be activated. Parallel actuation of the brake lights of the trailer vehicle meets the information requirement and thus the safety with respect to other road users.The haptic driver information by braking the trailer vehicle can additionally be supported by acoustic and / or visual signals being output in the towing vehicle and / or in / on the trailer vehicle.The aspects described here with respect to the method apply equally to the disclosed drive system for the autonomous drive of a trailer vehicle of a vehicle combination, in which the method is carried out by the brake control unit. This can be done by making suitable write and read accesses to a memory associated with the brake control unit. The method is implemented in particular within the trailer vehicle in hardware or software or else a combination of hardware and software. The hardware comprises in particular digital signal processors, application-specific integrated circuits, field programmable gate arrays and / or further suitable switching and computing components.Further features, advantages and characteristics of the invention will be explained by describing preferred embodiments of the invention with reference to the figures, which show: FIG. 1 shows a schematic illustration of a vehicle combination with a trailer vehicle comprising an exemplary embodiment of the drive system according to the invention, FIG. 2 shows a schematic illustration of the method according to the invention.FIG. 1 shows a schematic illustration of a vehicle combination with a trailer vehicle 3 comprising an exemplary embodiment of the drive system according to the invention. The vehicle combination 1 comprises a driven towing vehicle 2 and the trailer vehicle 3, which is electrically driven.For the respective drive, the towing vehicle 2 comprises a first drive system 4, comprising an engine 5, which can be designed as an internal combustion engine or an electric motor, and a first control unit 6. In addition, the second drive system 7 comprises a brake control unit 11 which is coupled to a brake modulator 12 in order to actuate brake actuators 13 which are assigned to the individual wheels 14 of the trailer vehicle 3 in order to brake them. For this purpose, the brake actuators 13 are arranged in a compressed air system, which is not shown in any more detail for the sake of clarity. When a braking process of the trailer vehicle 3 is carried out, brake lights 15 positioned on the rear side of the trailer vehicle 3 are actuated, which indicate to the following traffic that the vehicle combination 1 is braking.In the electric drive unit 8, the second control device 10 is connected to a fault detection unit 16, which monitors a function of the electric motor 9 during the travel of the vehicle combination 1. If the fault detection unit 16 detects a malfunction of the electric motor 9, this is immediately forwarded to the second control unit 10, which outputs a warning message for the driver of the vehicle combination 1 seated in the towing vehicle 2. This warning message is initiated by the second control device 10 outputting a warning signal to the brake control device 11, which then initiates intermittent short braking events via the brake modulator 12 in order to draw the attention of the driver. Such intermittent braking events are also known as so-called "sottling braking", in which short jerk-like brake actuations are carried out by the trailer vehicle 3. FIG. 2 shows an exemplary embodiment of these jerk-like brake actuations, which are embodied as brake pulses 17 and which begin when a malfunction FF has been detected. A possible curve of the brake pulses 17 is shown as vehicle deceleration over time.A further possibility for warning the driver may also consist in the braking control unit 11 outputting a signal for the permanent braking of the trailer vehicle 3 to a restricted maximum vehicle speed. It is likewise conceivable for a short drive pulse to be generated at the electric motor 9 between the brake pulses 17.A parallel actuation of the brake lights 15 alerts other road users and thus increases the safety in road traffic. In addition to the haptic driver information by braking the trailer vehicle 3, acoustic and / or visual signals can additionally be generated in the towing vehicle 2 and / or on the trailer vehicle 3 in order to increase the attention of the driver to a hazardous situation.Reference Sign (Part of Description)1 Vehicle combination 2 Towing vehicle 3 Trailer vehicle 4 First drive system 5 Engine 6 First control unit 7 Second drive system 8 Electrical drive unit 9 Electric motor 10 Second control unit 11 Brake control unit 12 Brake modulator 13 Brake actuator 14 Wheel 15 Brake lamp 16 Fault detection unit 17 Brake pulse FF MalfunctionReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2013 222 898 A1

[0002] US 2011 / 80282 A1

[0003] U.S. Pat. No. 4,145,682

[0004] FR 2261904 A

[0005]

Claims

Method for warning a driver of a vehicle combination (1) during a journey of the vehicle combination (1), in which a warning message is output if an error (FF) is detected on a trailer vehicle (3) of the vehicle combination (1), characterized in that the trailer vehicle (3) generates the warning message from a braking function of the trailer vehicle (3) as haptic feedback for the driver during the journey of the vehicle combination (1).Method according to Claim 1, characterized in that the haptic feedback is generated by varying braking interventions generated by an autonomous braking system (12, 13) of the trailer vehicle (3).Method according to claim 2, characterised in that the braking interventions comprise intermittent short braking pulses (17).Method according to Claim 3, characterized in that at least one short drive pulse is generated between the brake pulses (17).Method according to Claim 1, characterized in that the haptic feedback is generated by an independent braking of the trailer vehicle (3) to a restricted predefined speed.Method according to one of the preceding claims, characterized in that brake lamps (15) of the trailer vehicle (3) are actuated as a warning signal for other road users.Method according to one of the preceding claims, characterized in that an optical and / or acoustic signal is output as feedback to the driver in a towing vehicle (2) of the vehicle combination (1).Method according to one of the preceding claims, characterized in that the output of the warning message is interrupted if this is matched by a braking request initiated by the driver.Electric drive system for autonomous drive of a trailer vehicle (3) of a vehicle combination (1), comprising an electric drive unit (8) which is coupled to a brake control unit (11) which outputs brake signals to wheels (14) of the trailer vehicle (3) via a brake modulator (12), characterized in that the brake control unit (11) is designed to generate a haptic warning message as feedback to the driver from a braking function of the trailer vehicle (3) in the event of a fault (FF).Electric drive system according to Claim 9, characterized in that the brake control unit (11) is designed to trigger varying, in particular intermittent, brake pulses (17) as a warning message.Electric drive system according to Claim 9 or 10, characterized in that the brake control unit (11) is designed to brake the trailer vehicle (3) to a restricted predefined speed as a warning message.Electric drive system according to Claim 9, 10 or 11, characterized in that the brake control unit (11) is coupled to a control unit (10) of the drive unit (8) for generating short drive pulses during a braking process or the braking process initiated as a warning message.Electric drive system according to at least one of Claims 9 to 12, characterized in that the brake control unit (11) is designed to interrupt the output of the warning message if this is matched by a braking request which is triggered by the driver.

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