DE102020102847A1 - Emergency braking device for an autonomous vehicle and method for braking an autonomous vehicle - Google Patents

Abstract

An emergency braking device (20) for an autonomous vehicle with a control device (12), the vehicle having a braking device (10, 38, 40) which can be released by means of a hydraulic and / or pneumatic pressure built up in a pressure system (14) a venting device (22, 48, 50) for reducing the pressure, the emergency braking device (20) having a triggering device (24) for monitoring at least one parameter which indicates a malfunction and for triggering the venting device (22, 48, 50) due to of a result of monitoring. A method for emergency braking of an autonomous vehicle has the steps of monitoring at least one parameter of a device and / or device of the autonomous vehicle; Decide on the basis of the monitored parameter whether the control device (14) can initiate braking processes and trigger the venting device (22, 48, 50) if it is decided that the control device (14) cannot initiate braking processes.

Description

The invention relates to an emergency braking device for an autonomous vehicle which has a control device. Furthermore, the vehicle has a braking device which can be released by means of a hydraulic and / or pneumatic pressure built up in a pressure system.

In particular in commercial vehicles and rail vehicles, such braking devices have a spring-loaded brake.

Brake systems of vehicles are usually designed in such a way that they can be actuated both by a driver of the vehicle and, if necessary, by assistance systems. Even if an assistance system fails, the driver of the vehicle can actuate the braking system by means of an operating element and thereby brake the vehicle. This redundancy increases the safety of the vehicle in the event of a system failure.

Autonomous vehicles, on the other hand, should have no or only a few control elements. The control device takes over all the functions of the driver insofar as they relate to the journey of the vehicle. In such a vehicle, there are no longer any operating elements for operating the brake system by the driver. If the control device fails or malfunctions, the driver can no longer intervene in the functioning of the vehicle. Even if control elements for braking are present, there is no guarantee that a passenger who is not involved in the control processes of the vehicle will recognize a malfunction and intervene in good time.

Against this background, the present invention has the task of improving the safety of an autonomous vehicle.

The object is achieved by the features of claims 1 and 9. Further advantageous configurations are the subject of the dependent claims.

To achieve the object, an emergency braking device for an autonomous vehicle with a control device is proposed. The vehicle has a braking device which can be released by means of hydraulic and / or pneumatic pressure built up in a pressure system. The emergency braking device has a venting device for reducing the pressure and a triggering device for monitoring at least one parameter which indicates a malfunction and for triggering the venting device on the basis of a result of the monitoring.

This has the effect that, when the parameter indicates this, the venting device is triggered. The venting device then ventilates the pressure system and thus also the braking device. Since the braking device is only released when it receives pressure from the pressure system, the braking device begins to brake when this pressure is reduced. Braking is thus initiated when a malfunction of the control device has been recognized.

This has the advantage that an autonomous vehicle is also braked when the control device is no longer able to initiate braking due to a malfunction.

In a further advantageous embodiment, the venting device has a valve device which is connected to the pressure system and which can be opened to reduce the pressure.

Valve devices are widely known and can be manufactured reliably and inexpensively. After a braking process initiated by means of such a valve device has been completed, the valve device can be closed again and the pressure system can be refilled. It is also known to control valve devices in a variety of ways, for example electrically or with pressure.

In a further advantageous embodiment, the venting device has a pyrotechnic device, by means of which a section of the pressure system can be destroyed in order to reduce the pressure.

A pyrotechnic device has the advantage that it only requires a short ignition pulse to vent the pressure system and the braking device. This ensures that a braking process is reliably initiated even if the triggering device is destroyed quickly after a malfunction of the control device has been detected.

In a further advantageous embodiment, the venting device has a mechanical energy storage device, the energy storage device having a predetermined breaking section breakthrough device, by means of which a predetermined breaking section of the pressure system can be severed in order to reduce the pressure. The predetermined breaking section breakthrough device is designed to operate with energy stored in the energy storage device.

Similar to the pyrotechnic device, it is hereby possible, after triggering, to initiate a braking process that functions independently of the triggering device. In addition, are mechanical energy storage is easy to handle and inexpensive to manufacture.

In a further advantageous embodiment, the venting device has a flow delay device, by means of which the reduction in pressure can be slowed down.

As a result, the pressure in the printing system is not completely reduced immediately, but slowly over a definable period of time. Thus, the braking effect does not take place immediately and completely. The vehicle is therefore first decelerated and only then fully braked. This counteracts the blocking of the braked wheel or wheels of the vehicle.

In a further advantageous embodiment, the parameter is an electrical voltage and the triggering device is set up to trigger the venting device when the voltage leaves a permitted range.

Thus, for example, an operating voltage of a device of the vehicle, for example the control device, can advantageously be checked. If the operating voltage drops so sharply that it leaves the range permitted for the control device, the triggering device causes the venting device to be triggered. In the event of an operating voltage failure, the vehicle is automatically braked.

In a further advantageous embodiment, the parameter is determined by the receipt of a trigger signal. The triggering device has an input for receiving the triggering signal and is set up to trigger the venting device when the triggering signal is received.

If other devices and / or devices of the vehicle detect a malfunction that makes an emergency braking process necessary, this can be transmitted to the input in the form of a trigger signal and the emergency braking device can thus be triggered.

In a further advantageous embodiment, the parameter is a functional parameter of a device of the autonomous vehicle. The triggering device is set up to trigger the venting device when the functional parameter leaves a predetermined range.

As a result, emergency braking is triggered if certain devices and / or devices, the function of which is being tested, no longer provide this function or do not provide this function to a sufficient extent.

The object is also achieved by a method for emergency braking of an autonomous vehicle with the features mentioned above, which has the following steps: monitoring at least one parameter of a device and / or device of the autonomous vehicle; Decide, based on the monitored parameter, whether the control device can initiate braking processes and triggering the venting device if it is decided that the control device cannot initiate braking processes.

As soon as a device and / or device required for a regular braking process can no longer fulfill its function, emergency braking is initiated.

• 1 eine schematische Darstellung einer Notbremseinrichtung gemäß einer ersten Ausführungsform der Erfindung;
• 2 eine schematische Darstellung einer Notbremseinrichtung gemäß einer zweiten Ausführungsform der Erfindung;
• 3 eine schematische Darstellung eines Drucksystems mit einer Notbremseinrichtung gemäß einer dritten Ausführungsform der Erfindung und
• 4 eine schematische Darstellung eines Drucksystems mit einer Notbremseinrichtung gemäß einer vierten Ausführungsform der Erfindung.

Further features and embodiments of the invention can be seen from the accompanying figures, which show forms of the invention only schematically. They show in detail:

• 1 a schematic representation of an emergency braking device according to a first embodiment of the invention;
• 2 a schematic representation of an emergency braking device according to a second embodiment of the invention;
• 3 a schematic representation of a printing system with an emergency braking device according to a third embodiment of the invention and
• 4th a schematic representation of a printing system with an emergency braking device according to a fourth embodiment of the invention.

1 shows a braking device 10 an autonomous vehicle with an emergency braking device 20th according to one embodiment of the invention. The braking device 10 is designed as a spring-loaded brake. In the case of a spring-loaded brake, brake linings are pressed against a brake disc or brake drum by means of a mechanical spring. In order to release the spring-loaded brake, a force must therefore be applied. This force is exerted here by means of a pneumatic cylinder, which by means of a pressure system 14th is applied with a pneumatic pressure, whereby the braking device 10 is resolved. The printing system 14th can also be controlled in such a way that no pneumatic pressure is introduced into the pneumatic cylinder. In this case, the force of the mechanical spring is not counteracted by any other force, so that the brake linings are pressed against the brake disc or brake drum.

The autonomous vehicle has a control device 12th on which the vehicle is autonomous controls. The control device 12th is set up to autonomously control devices of the vehicle, in particular for accelerating, braking and steering. The vehicle has no driver's seat and also no operating elements by means of which a passenger can operate the braking device 10 could trigger.

The control device 12th has a power supply 16 on which an electrical power supply with an operating voltage of 5 V for the control device 12th provides. As soon as the operating voltage falls below 4.6 V, the control device is functioning correctly 12th no longer guaranteed. This means that any necessary braking processes are not reliably triggered. Since the vehicle has no controls to trigger the braking device 10 has, no passenger of the vehicle can trigger such a braking process.

In order to trigger reliable, controlled braking in this situation, the vehicle has the emergency braking device 20th on. The emergency braking device 20th has a ventilation device 22nd on that on the printing system 14th is arranged. The ventilation device 22nd when triggered, vents the pressure system 14th and the braking device 10 . As a result, the vehicle is forcibly braked.

The venting of the pressure system 14th happens by having one in the printing system 14th contained pressure medium an opening is provided through which it from the pressure system 14th can escape. The pressure in the pressure system is increased by the escape of the pressure medium 14th reduced. The escaping pressure medium can later be returned to the pressure system 14th may be collected.

In order to be able to determine a point in time in which the venting device 22nd is to be triggered to force such a braking process, the emergency braking device 20th one with the vent 22nd connected release device 24 that monitors a parameter and, if the parameter leaves a previously defined range, the venting device 22nd triggers.

In the present embodiment, the trigger device is 24 with the power supply 16 connected and monitored as a parameter, the operating voltage by means of a measuring device. The measuring device measures the operating voltage of the power supply several times per second 16 and forwards the measured operating voltage to a decision device. The decision device compares the measured operating voltage with the previously defined limit value of 4.6 V. If the decision device detects that the measured operating voltage falls below the limit value, it then decides that the control device is functioning correctly 12th is no longer guaranteed and that the control device 12th can no longer initiate braking. Based on this decision, the release mechanism triggers 24 the ventilation device 22nd and thus causes, as described above, a compulsory braking of the vehicle.

In the present embodiment, the measuring device and the decision device are designed as parts of a computer. In order to pass on the measured operating voltage, the measuring device thus generates a digital value which represents the operating voltage of the power supply 16 reproduces.

In further embodiments, instead of a digital measuring device, any other device for monitoring the operating voltage can be used, for example an analog comparison device, for example an operational amplifier or comparator, which is set up to compare the operating voltage with a reference voltage.

In further embodiments, the operating voltage and the limit value can assume any other value. Often used operating voltages of electrical systems in vehicles are, for example, 12 V and 24 V. The limit value can be, for example, 10% or 15% below the operating voltage.

2 shows a braking device 10 an autonomous vehicle with an emergency braking device 20th according to a further embodiment of the invention. This embodiment is in part consistent with the embodiment of FIG 1 match. Therefore, only the differences between the two embodiments will be discussed below.

The release mechanism 24 is by means of a control line 26th with a communication interface of the control unit 12th connected. By means of the control line 26th can the release mechanism 24 with the control unit 12th communicate. To do this, messages are sent between the release mechanism 24 and the control unit 12th exchanged. The release mechanism 24 instructs to monitor the function of the control unit 12th a timekeeping device. The triggering device measures by means of the timer device 24 a response time between the transmission of a message from the trigger device 24 to the control unit 12th and an associated response from the control unit 12th to the release device 24 passes. The release mechanism 24 transmits such a message several times per second to the control unit 12th and measures the response time. The response time provides information about the function of the control unit 12th and thus forms a functional parameter.

If the response time exceeds a previously defined limit value, the triggering device triggers 24 the ventilation device 22nd and thus causes the vehicle to brake automatically.

In further embodiments, the triggering device 24 for example, monitor other processing units for a failure. In addition, the release mechanism 24 have an input which is suitable for receiving a trigger signal. When such a triggering signal is received, the triggering device triggers 24 the ventilation device 22nd the end. It is thus possible, for example, to arrange measuring devices and / or decision-making devices at a different location in the vehicle and to send trigger signals generated by them, for example by means of a signal line and / or a control line, to one in the vicinity of the printing system 14th and / or the braking device 10 arranged emergency braking device 20th to submit.

In a further embodiment, the triggering device 24 have a plurality of inputs which are suitable for receiving a trigger signal, the triggering device 24 the ventilation device 22nd triggers when a trigger signal is received on any input. Alternatively, it may also be desirable that, for example, several trigger signals have to be received on one or more inputs so that the triggering device can be used 24 the ventilation device 22nd triggers.

3 shows part of a printing system 14th with a compressor 32 , an air dryer 34 as well as a four-circuit protection valve 36 . It's just that part of the printing system 14th shown, the operation of a first braking device 38 and a second braking device 40 is used. The printing system 14th has a check valve 42 , a hand brake valve 44 and a valve device designed as a relay valve 46 on. The braking devices 38 and 40 are each designed as a spring-loaded brake.

The relay valve 46 has a ventilation device 22nd on, by means of a release device 24 can be triggered. When the vent 22nd is triggered, the relay valve opens 46 and vent the pressure system 14th and the braking devices 38 and 40 . The relay valve 46 vents the pressure system 14th not at the maximum possible speed, but has a flow delay device in the form of a throttle device, by means of which a pressure medium at a reduced speed from the pressure system 14th is diverted. This causes the venting device to be triggered 22nd no abrupt braking. Instead, the braking force is built up gradually over a predetermined period of time. The vehicle is first decelerated and only then fully braked. As a result, locking of the braked wheels can be delayed or, in the best case, avoided entirely.

4th shows part of the printing system 14th an autonomous vehicle with an emergency braking device 20th according to a further embodiment of the invention. This embodiment is in part consistent with the embodiment of FIG 3 match. Therefore, only the differences between the two embodiments will be discussed below.

A connection of the first braking device 38 to the printing system 14th has a first venting device 48 on. A connection of the second braking device 40 to the printing system 14th has a second ventilation device 50 on. The ventilation devices 48 , 50 are equipped with a release mechanism 24 connected.

Any of the vents 48 , 50 has a pyrotechnic device, which when triggered by means of the triggering device 24 the printing system 14th bursts open, after which the pressure system 14th and in particular the braking devices 38 , 40 be vented.

Also the ventilation device 48 , 50 each have a throttle device in order to avoid an abrupt braking process in which the wheels of the vehicle could lock.

In further embodiments, a reduction, constriction or some other damping device can be used as the flow delay device in the venting device 22nd , 48 , 50 to get integrated.

A common inventive concept of all embodiments is that the triggering device triggers the venting device and thereby a braking operation of the braking device after recognizing a state in which control of the braking device is no longer possible or expected by the autonomous vehicle.

In further embodiments, the vehicle can in particular be a utility vehicle, for example a truck or a bus, or a rail vehicle.

In further embodiments, the parameter that is monitored by the triggering device can be selected such that it indicates any malfunction that would lead to a failure of the regular braking function triggered by the control device. A parameter indicates such a malfunction when its value no longer allows the control device to function correctly. For example, as described above, an operating voltage of the control device can be selected as a parameter. If the operating voltage of the control device falls below a certain, previously known value, then the control device can no longer function correctly and emergency braking must be triggered.

In further embodiments, the ventilation device 22nd and / or the release device 24 in existing facilities of the braking device 10 and / or the printing system 14th be integrated or as a separate device of an existing braking device 10 and / or an existing printing system 14th to be added.

The invention makes it possible, for example, in the event of a failure of the control device 12th or any other processing device of the service brake to bring about a deceleration and a locking of a vehicle. This reduces the risk of accidents in the event of such a failure and its consequences.

List of reference symbols

10

Braking device

12th

Control device

14th

Printing system

16

Power supply

20th

Emergency braking device

22nd

Ventilation device

24

Release mechanism

26th

Control line

32

compressor

34

Air dryer

36

Four-circuit protection valve

38

first braking device

40

second braking device

42

check valve

44

Hand brake valve

46

Relay valve (valve device)

48

first venting device

50

second ventilation device

Claims (9)

Emergency braking device (20) for an autonomous vehicle with a control device (12), the vehicle having a braking device (10, 38, 40) which can be released by means of a hydraulic and / or pneumatic pressure built up in a pressure system (14), characterized that the emergency braking device (20) has a venting device (22, 48, 50) for reducing the pressure and wherein the emergency braking device (20) has a triggering device (24) for monitoring at least one parameter which indicates a malfunction and for triggering the venting device ( 22, 48, 50) on the basis of a result of the monitoring. Emergency braking device according to Claim 1 , characterized in that the venting device (22, 48, 50) has a valve device (46) which is connected to the pressure system (14) and which can be opened to reduce the pressure. Emergency braking device according to one of the preceding claims, characterized in that the venting device (22, 48, 50) has a pyrotechnic device, by means of which a section of the pressure system (14) can be destroyed in order to reduce the pressure. Emergency braking device according to one of the preceding claims, characterized in that the venting device (22, 48, 50) has a mechanical energy storage device, the energy storage device having a predetermined breaking section breakout device by means of which a predetermined breaking section of the pressure system (14) can be severed to reduce the pressure and wherein the Is designed predetermined breaking portion breakthrough device for operation with an energy stored in the energy storage device. Emergency braking device according to one of the preceding claims, characterized by a flow delay device, by means of which the reduction in pressure can be slowed down. Emergency braking device according to one of the preceding claims, characterized in that at least one parameter is an electrical voltage and wherein the triggering device (24) is set up to trigger the venting device (22, 48, 50) when the voltage leaves a permitted range. Emergency braking device according to one of the preceding claims, characterized in that at least one parameter is determined by the receipt of a triggering signal, the triggering device (24) has an input for receiving the triggering signal and the triggering device for triggering the venting device (22, 48, 50) Reception of the trigger signal is established. Emergency braking device according to one of the preceding claims, characterized in that at least one parameter is a functional parameter of a device of the autonomous vehicle and wherein the triggering device (24) is set up to trigger the venting device (22, 48, 50) when the functional parameter leaves a predetermined range is. Method for emergency braking of an autonomous vehicle according to one of the preceding claims, characterized by the steps of: monitoring at least one parameter of a device and / or device of the autonomous vehicle; Decide on the basis of the monitored parameter whether the control device (14) can initiate braking processes and triggering the venting device (22, 48, 50) if it is decided that the control device (14) cannot initiate braking processes.

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