Method for controlling a driver assistance system in a road vehicle and device and vehicle for performing the method

Abstract

The invention relates to a method for controlling a driver assistance system in a road vehicle (22) having an electronically controllable drive motor (24) and an electronically controllable service brake system having wheel brake cylinders (30, 32, 34, 36) which can be actuated with pressure medium, and having a camera-based vehicle recognition, pedestrian recognition and traffic sign recognition, as well as a speed regulation function and an emergency brake function, wherein, when the road vehicle (22) approaches an identified bus stop or tram stop (2), the controller (26) of the driver assistance system, in addition to generating and outputting a warning signal to the driver of the road vehicle (22), also carries out at least one further measure to avoid a collision with a pedestrian (14.1, 14.2, 14.3). As an additional measure, according to the invention, the wheel brake cylinders (30, 32, 34, 36) of the service brake system of the road vehicle (22) are pre-filled with a predetermined fluid pressure before reaching the bus stop or tram stop (2) in order to prepare for a possible emergency brake. The invention also relates to a device (40) for carrying out the method.

Description

Technical Field

[0001] This invention relates to a method for controlling a driver assistance system in a road vehicle, the road vehicle having an electronically controllable drive motor and an electronically controllable service braking system, the service braking system having wheel brake cylinders operable by a pressure medium, and the driver assistance system of the road vehicle having camera-based vehicle recognition, pedestrian recognition, and traffic sign recognition, as well as speed regulation and emergency braking functions. When the road vehicle approaches a recognized bus stop or tram stop, the controller of the driver assistance system, in addition to generating and outputting warning signals to the driver of the road vehicle, performs at least one additional measure to avoid a collision with a pedestrian. The invention also relates to an apparatus on a road vehicle for performing this method. Background Technology

[0002] Dangerous locations exist on public roads, such as road intersections, merging points, and high-traffic areas like the entrances and exits of parking lots near supermarkets, businesses, and tourist destinations. Experience shows that vehicle-to-vehicle collisions are relatively frequent at these locations. Conversely, bus and tram stops, often located at the edges of roads in urban and regional areas, are also potential danger points for vehicle-pedestrian collisions. This is because pedestrians at these stops often cross adjacent roads using the shortest route to catch their vehicles (buses or trams) or to reach their destinations (homes, workplaces, or supermarkets) as quickly as possible after disembarking. Therefore, there is a general need to improve traffic safety at bus and tram stops by preventing collisions between vehicles passing through these stops and pedestrians crossing the road in the stop area.

[0003] In this context, a method for camera-based traffic sign recognition in a motor vehicle is known from DE 10 2015 225 900 B3, in which a traffic sign is considered to be associated with the motor vehicle when the relative speed of the motor vehicle moving toward a traffic sign sensed by its camera and subsequently recognized is within a predetermined tolerance to the speed of the motor vehicle.

[0004] US 2022 / 0 234 578 A1 describes an emergency braking assist for a road vehicle that determines the possible point of collision between the vehicle and an identified pedestrian as the intersection of their respective known trajectories, based on the current positions and speeds of two road users. In the event of approach to the collision point, emergency braking of the vehicle is triggered when it is anticipated that the two road users will arrive at the collision point approximately simultaneously.

[0005] A driver assistance system for road vehicles is known from DE 10 2011 018 157 A1, which identifies bus or tram stops located at the edge of the road based on prompts and image data detected by a camera, and outputs acoustic and / or optical warning signals to the vehicle driver based on the identified traffic conditions, such as when a bus stops at a stop. Summary of the Invention

[0006] The objective of this invention is to improve known methods for controlling driver assistance systems in road vehicles, thereby further enhancing traffic safety at bus and tram stops. Furthermore, a device on a road vehicle should be proposed, which enables the execution of the improved method.

[0007] The solution to this task is achieved using a method or apparatus having the features of the respective independent claims. Advantageous improvements are defined in the dependent claims.

[0008] Therefore, the present invention first relates to a method for controlling a driver assistance system in a road vehicle having an electronically controllable drive motor and an electronically controllable service braking system having wheel brake cylinders operable by a pressure medium. The driver assistance system of the road vehicle has camera-based vehicle recognition, pedestrian recognition, and traffic sign recognition, as well as speed regulation and emergency braking functions. When the road vehicle approaches a recognized bus stop or tram stop, the controller of the driver assistance system, in addition to generating and outputting warning signals to the driver of the road vehicle, performs at least one additional measure to avoid collision with a pedestrian.

[0009] To address the proposed task, the method includes a system in which the wheel brake cylinders of the road vehicle's service braking system are pre-filled with a predetermined fluid pressure before reaching a bus stop or tram stop in preparation for possible emergency braking.

[0010] By pre-filling the wheel brake cylinders with compressed air or brake fluid, the brake pads of the service brake system are secured to the corresponding brake discs or drums, eliminating conventional gaps without significantly slowing the vehicle. Consequently, the wheel brakes respond immediately to braking maneuvers, especially in emergency braking, allowing the vehicle to decelerate and come to a stop faster and earlier than usual. This increases the likelihood of preventing collisions with pedestrians or at least achieves lower impact speeds.

[0011] Therefore, the system is designed to identify bus or tram stops using cameras, without requiring any such public transport vehicle to be present, and to automatically pre-fill the wheel brake cylinders of road vehicles. This pre-filling of the wheel brake cylinders always occurs before reaching the stop, meaning it is independent of the driver's later decision regarding slowing the vehicle. Subsequently, the vehicle's deceleration is also automatic, requiring no manual operation of the brake pedal by the driver.

[0012] Following a braking process, which may be triggered by the driver operating the brake pedal or automatically, the wheel brake cylinders are switched to depressurization. This causes the brake pad carriers (brake blocks in disc brakes and brake shoes in drum brakes) to disengage from and maintain a distance from the brake elements fixed relative to the wheel (brake discs in disc brakes and brake drums in drum brakes). This is achieved in disc brakes, for example, by the smaller lateral runout of the brake disc and the restoring force of the piston seals that elastically deform in the bores of the brake calipers, while in drum brakes, it is achieved by the return springs between the brake shoes.

[0013] Further improvements in traffic safety can be achieved by reducing the speed of road vehicles, as this significantly shortens braking distance, especially during emergency braking. To this end, an improvement to the method involves automatically decelerating a road vehicle when its speed exceeds a safe speed appropriate to the identified traffic conditions at the stop and the brake pedal is not engaged. Upon engagement of the brake pedal, the responsibility for avoiding a collision is transferred from the driver assistance system to the driver.

[0014] To assess traffic conditions at a station, four scenarios can be distinguished, namely: The first scenario is "there are no buses or trams stopping in front of the station". The second scenario is "a bus or tram with its warning lights turned off is parked in front of the station". The third scenario is "a bus or tram with its warning lights on is parked in front of the stop". And the fourth situation is "a bus or tram with its right-hand drive indicator flashing is parked in front of the station".

[0015] In countries that drive on the left, such as Japan or the UK, the fourth situation is appropriately described as: "A bus or tram with a flashing left-hand drive indicator is stopped in front of the stop."

[0016] The fourth situation is also classified as follows: in which, although the warning lights are not turned on, the bus or tram is stationary, and it can be considered that the stopped bus or tram is a special hazard to pedestrians and therefore requires special attention.

[0017] Furthermore, the safe speed can be additionally determined by whether the station is located inside or outside a closed residential area. Here, the safe speed for stations located inside closed residential areas is specified as lower than the safe speed for stations located outside closed residential areas.

[0018] Therefore, it is possible to set up a system where road vehicles, when approaching a stop where no bus or tram stops, slow down to a safe speed of 30 km / h within a closed residential area, and slow down to a safe speed of 50 km / h outside a closed residential area.

[0019] Similarly, it can be configured that when road vehicles approach a bus or tram stop with its warning lights turned off, they should slow down to a safe speed of 15 km / h within the closed residential area, and slow down to a boundary speed of 25 km / h outside the closed residential area.

[0020] When passenger vehicles, such as buses or trams, are stopped in front of a station, extra caution should be exercised because pedestrians may be already on the road behind the vehicle in the direction of observation and may suddenly emerge from the vehicle's blind spot.

[0021] To take this into account, it could be configured that road vehicles approaching bus or tram stops with warning lights on should slow to a safe speed of 7 km / h or walking speed, both inside and outside enclosed residential areas.

[0022] Another design option for the method is to generate and output the aforementioned warning signal only when a road vehicle travels faster than a predetermined safe speed or walking speed. This safe speed or walking speed could be, for example, 7 km / h.

[0023] To avoid premature wear of brake pads and damage to wheel brakes caused by overheating, it can also be configured such that, once the automatic deceleration of the road vehicle ceases, the brake pedal of the road vehicle is not operated, and there are no other functional requirements to prefill the wheel brake cylinders with pressurized fluid, the wheel brake cylinders of the service braking system are switched to unpressurized state after passing a station.

[0024] Finally, the method can be configured such that if, after pre-filling the wheel brake cylinders, the driver assistance system detects a pedestrian walking in front of the bus or tram in the direction of travel, the road vehicle automatically and with full braking force decelerates until it comes to a stop.

[0025] As mentioned at the beginning, the present invention also relates to an apparatus on a road vehicle by means of which the method is performed. The apparatus has a controller for a driver assistance system, which is signal-technically connected to a camera disposed at the front of the vehicle. Furthermore, the controller is also connected via a data line to a controller for the service brake system of the road vehicle. The controller for the service brake system is connected via a control line to an electromagnetic switching valve, which, in its open state, directs a fluid pressure medium to the wheel brake cylinders of the road vehicle's service brakes. The controller for the driver assistance system is configured to, after the camera supports the identification of a visible bus or tram stop ahead of the road vehicle, send relevant information to the controller for the service brake system, and the controller for the service brake system is configured to, upon receiving such information, open the switching valve to pre-fill the wheel brake cylinders with pressure medium, and subsequently close the switching valve again.

[0026] The present invention also relates to a vehicle equipped with the device according to the present invention. Attached Figure Description

[0027] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings. In the drawings: Figure 1 A schematic diagram of a bus stop at the edge of a road is shown; Figure 2 It shows that according to Figure 1 A diagram showing a bus stop and a bus with its warning lights turned off parked in front of it; Figure 3 It shows that according to Figure 1 A diagram showing the bus stops and the buses with their warning lights on; and Figure 4 The image shows an overhead view of a bus stop on the road, buses parked there, and road vehicles approaching the bus stop. Detailed Implementation

[0028] Figure 1The bus stop 2 depicted is located on the sidewalk 5, adjacent to the road edge 6 of road 4. Stop 2 includes a reinforced ground surface 8, a shelter 10, and a stop traffic sign 12 conforming to German traffic sign VZ 224. Three people are exemplarily present at stop 2: a man 14.1, a woman 14.2, and a child 14.3. Stop 2 is roughly drawn as would be perceived by a driver of a road vehicle 22 as it approaches the stop.

[0029] exist Figure 2 The image shows the same stop 2 and a bus 16 parked in front of it, with its lower warning lights 18 and upper warning lights 20 turned off. Figure 3 The diagram illustrates a traffic situation similar to that at stop 2 where bus 16 is stopped ahead; however, in this bus 16, warning lights 18 and 20 are identifiable as being on. When warning lights 18 and 20 are flashing only on the respective vehicle side, they can also be used as right-hand drive indicators 18a and 20a or left-hand drive indicators 18b and 20b.

[0030] Figure 4 A road vehicle 22 configured as a passenger car is shown, having the following device 40 for performing the method according to the invention. Figure 4 This illustrates a scenario where a road vehicle 22 has approached station 2 to such an extent that the station can be autonomously identified by the driver assistance system of the road vehicle 22 using a camera 28 positioned at the front of the vehicle. The detection area 29 of the camera 28, relevant to identification, is exemplarily indicated by two dashed lines. This identification of station 2 is performed, for example, based on features related to road construction and / or station construction and / or on the station traffic sign 12 erected at station 2.

[0031] The driver assistance system of the road vehicle 22 is a component of the device 40 for performing the method according to the invention, which is constructed on the road vehicle 22. The driver assistance system has suitable software stored in the controller 26 of the driver assistance system. The controller 26 of the driver assistance system is connected to the aforementioned camera 28 in a signal technology manner. Furthermore, the controller 26 of the driver assistance system is also connected via data line 44 to the controller 38 of the service braking system of the road vehicle 22.

[0032] The service brake controller 38 controls the braking operation of the service brakes of the road vehicle 22, and responds to manually operated brake pedals of the road vehicle 22 in a known manner during normal driving. However, the service brake controller 38 can also, when necessary, control braking operation until the vehicle comes to a stop under commands from other controllers of the road vehicle 22, such as based on information from speed regulation and / or distance regulation functions. These functions are stored, for example, in the controller 26 of the driver assistance system. When braking is required, the service brake controller 38 operates an electromagnetic switching valve (not shown but known in itself), through which a fluid or gaseous pressurized medium is directed to the wheel brake cylinders 30, 32, 34, and 36 of the road vehicle 22.

[0033] The road vehicle 22 also has an electronically controlled drive motor 24 for propelling the road vehicle forward, but can also indirectly increase the pressure of the fluid used to operate the service brakes with the help of a compressor or other fluid pump.

[0034] Alternatively, in vehicles equipped with air-operated brakes, pressure is diverted from a pressure accumulator to the service brake. A suitable pressure is then generated at the service brake via a controllable solenoid valve. Air-operated service brakes are primarily installed on commercial vehicles, especially trucks and their associated trailers.

[0035] The driver assistance system controller 26 is configured to send relevant information to the service brake system controller 38 after the camera-supported identification of a visible stop 2 ahead of the road vehicle 22. Furthermore, the service brake system controller 38 is also configured to send control signals to open the aforementioned solenoid valves upon receiving such information, in order to partially fill the wheel brake cylinders 30, 32, 34, and 36 at the service brake. Once this pre-filling process is complete, the service brake system controller 38 can send control signals to close the solenoid valves.

[0036] Therefore, the method claimed herein utilizes a controller 26 of a driver assistance system. This controller utilizes camera-based recognition capabilities to identify vehicles, pedestrians, and traffic signs. Furthermore, the driver assistance system also utilizes speed regulation and emergency braking functions when needed. The aforementioned functions of the driver assistance system are implemented in the controller 26 of the driver assistance system using corresponding computer software that evaluates data from appropriate sensors and generates control signals for the actuators of the road vehicle 22 and sends these signals to those actuators.

[0037] Upon approaching the identified bus stop 2, in addition to issuing a warning signal to the driver, the wheel brake cylinders 30, 32, 34, and 36 of the road vehicle 22 are pre-filled with the aforementioned fluid in preparation for possible emergency braking. This ensures that the wheel brakes respond immediately to emergency braking and shorten the braking distance, thereby increasing the likelihood of preventing collisions with persons 14.3 (see [link to relevant documentation]). Figure 4 The location of station 2 can also be identified using a navigation system combined with a digital road map containing station 2. However, it is preferable to use the traffic sign recognition function of a driver assistance system, which can identify the station traffic sign 12, because this approach detects the current traffic conditions in real time.

[0038] To further improve traffic safety at station 2, an additional feature is provided that when the speed of a road vehicle exceeds a safe speed that is commensurate with the identified traffic conditions at station 2 and the brake pedal of road vehicle 22 is not operated, the road vehicle is automatically decelerated.

[0039] Therefore, the current traffic situation at the station can be divided into four situations: the first situation is "no bus or tram is stopped in front of the station", the second situation is "a bus or tram with its warning lights off is stopped in front of the station", the third situation is "a bus or tram with its warning lights on is stopped in front of the station", and the fourth situation is "a bus or tram with its right-hand drive indicator flashing is stopped in front of the station".

[0040] Similarly, the safe speed can be determined based on whether station 2 is located inside or outside a closed residential area. Here, the safe speed determined for station 2 located inside a closed residential area is generally lower than that determined for station 2 located outside a closed residential area.

[0041] In an exemplary implementation, the function of automatically decelerating road vehicle 22 can be configured such that road vehicle 22 approaches a stop 2 where no bus 16 is stopped (according to...). Figure 1 When traffic conditions are as follows, reduce speed to a safe speed of 30 km / h within enclosed residential areas and to a safe speed of 50 km / h outside enclosed residential areas.

[0042] In addition, road vehicle 22 approaches bus stop 2 ahead of it, where the warning lights 18 and 20 are turned off (according to...). Figure 2When approaching a closed residential area (based on traffic conditions), the vehicle should reduce its speed to a safe speed of 15 km / h within the closed residential area, and to a boundary speed of 25 km / h outside the closed residential area. Finally, when approaching a bus stop 2 ahead of a bus 16 with its warning lights 18 and 20 activated or its right-of-way indicators 18a and 20a flashing (according to traffic conditions), the vehicle should reduce its speed to a safe speed of 15 km / h within the closed residential area, and to a boundary speed of 25 km / h outside the closed residential area. Figure 3 When traffic conditions are favorable, reduce speed to a safe speed of 7 km / h (walking speed) both inside and outside enclosed residential areas. In countries where driving on the left is permitted, the same applies if the direction indicator 18b or 20b of a stopped bus 16 is flashing on the left side of the vehicle.

[0043] List of reference numerals (part of the instruction manual)

[0044] 2. Bus stops

[0045] 4 Roads

[0046] 5. Sidewalk

[0047] 6. Road edge

[0048] 8. Ground level of the station

[0049] 10 Bus shelter

[0050] 12 Station Traffic Signs

[0051] 14.1 Personnel, Men

[0052] 14.2 Personnel, Women

[0053] 14.3 Personnel, Children

[0054] 16 Buses

[0055] 18. Warning lights on the bus

[0056] 18a Right lower driving direction indicator

[0057] 18b Lower left driving direction indicator

[0058] 20 Warning lights on buses

[0059] 20a Right-side driving direction indicator

[0060] 20b Left-side driving direction indicator

[0061] 22 Road vehicles

[0062] 24 drive motors

[0063] 26. Controller for driver assistance systems

[0064] 28 cameras

[0065] Detection area of ​​camera 29

[0066] 30. Wheel brake cylinders of the service braking system, front right.

[0067] 32. Wheel brake cylinders of the service braking system, front left.

[0068] 34. Wheel brake cylinders of the service braking system, right rear

[0069] 36. Wheel brake cylinders of the service braking system, left rear

[0070] 38. Controller for service braking system

[0071] 40. Equipment on road vehicles for performing methods

Claims

1. A method for controlling a driver assistance system in a road vehicle (22), the road vehicle having an electronically controllable drive motor (24) and an electronically controllable service braking system having wheel brake cylinders (30, 32, 34, 36) operable by a pressure medium, and the driver assistance system of the road vehicle having camera-based vehicle recognition, pedestrian recognition, and traffic sign recognition, as well as speed regulation and emergency braking functions, wherein, When the road vehicle (22) approaches a identified bus stop or tram stop (2), the controller (26) of the driver assistance system, in addition to generating and outputting warning signals to the driver of the road vehicle (22), performs at least one additional measure to avoid collision with pedestrians (14.1, 14.2, 14.3), characterized in that the wheel brake cylinders (30, 32, 34, 36) of the service braking system of the road vehicle (22) are pre-filled with a predetermined pressure before reaching the bus stop or tram stop (2) to prepare for possible emergency braking.

2. The method according to claim 1, characterized in that, When the speed of the road vehicle exceeds a safe speed that is commensurate with the traffic conditions identified at the station (2) and the brake pedal of the road vehicle (22) is not operated, the road vehicle (22) is automatically decelerated.

3. The method according to claim 2, characterized in that, When judging the traffic conditions at the station (2), the following conditions are distinguished: the first condition is "no bus (16) or tram is stopped in front of the station (2); the second condition is "a bus (16) or tram with its warning lights (18, 20) turned off is stopped in front of the station (2); the third condition is "a bus or tram with its warning lights turned on is stopped in front of the station"; and the fourth condition is "a bus or tram with its right-hand drive indicator (18a, 20a) flashing is stopped in front of the station".

4. The method according to claim 2 or 3, characterized in that, The corresponding safe speed additionally depends on whether the location of the station (2) is inside or outside a closed residential area, wherein the safe speed for the station (2) located inside a closed residential area is specified to be lower than the safe speed for the station (2) located outside a closed residential area.

5. The method according to any one of claims 2 to 4, characterized in that, When the road vehicle (22) approaches a station (2) where no bus (16) or tram stops, it slows down to a safe speed of 30 km / h within the enclosed residential area and to a safe speed of 50 km / h outside the enclosed residential area.

6. The method according to any one of claims 2 to 4, characterized in that, When the road vehicle (22) approaches a bus (16) or tram stop (2) with its warning lights (18, 20) turned off, it shall decelerate to a safe speed of 15 km / h within the closed residential area and to a boundary speed of 25 km / h outside the closed residential area.

7. The method according to any one of claims 2 to 4, characterized in that, When the road vehicle (22) approaches a bus (16) or tram stop (2) with warning lights (18, 20) turned on, it shall reduce its speed to a safe speed of 7 km / h or walking speed both inside and outside the enclosed residential area.

8. The method according to any one of the preceding claims, characterized in that, The alarm signal is generated and output only when the road vehicle (22) travels faster than the predetermined safe speed or walking speed.

9. The method according to any one of the preceding claims, characterized in that, As long as the automatic deceleration of the road vehicle (22) ceases, the brake pedal of the road vehicle (22) is not operated, and there are no other functional requirements to prefill the wheel brake cylinders (30, 32, 34, 36) with pressure medium, the wheel brake cylinders (30, 32, 34, 36) of the service braking system are switched to no pressure after passing the station (2).

10. The method according to any one of the preceding claims, characterized in that, If, after the wheel brake cylinders (30, 32, 34, 36) are pre-filled, the driver assistance system detects that a pedestrian (14.3) has stepped out in front of the bus (16) or the tram in the direction of travel, the road vehicle (22) automatically and with full braking force decelerates to a stop.

11. An apparatus (40) on a road vehicle (22) for performing the method according to any one of the method claims, characterized in that, The device has a driver assistance system controller (26) that is signal-connected to a camera (28) located at the front of the vehicle. The driver assistance system controller (26) is connected via a data line (44) to the controller (38) of the service braking system of the road vehicle (22). The service braking system controller (38) is connected via a control line to an electromagnetic switching valve. When the electromagnetic switching valve is open, it can fill the wheel brake cylinders (30, 32, 34, 36) of the service brake of the road vehicle (22) with fluid or gas. The driver assistance system controller (26) is also configured to send information related to the pressure medium to the service brake controller (38) after the camera supports the identification of a bus (16) or tram stop (2) visible ahead of the road vehicle (22). The service brake controller (38) is also configured to open the switching valve to prefill the wheel brake cylinders (30, 32, 34, 36) with pressure medium after receiving such information and then close the switching valve again.

12. A vehicle equipped with service braking facilities, characterized in that, The vehicle (22) is equipped with the device according to claim 11.

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