Unmanned logistics vehicle emergency braking system and method and vehicle

Abstract

The invention discloses an unmanned logistics vehicle emergency braking system and method and a vehicle, and belongs to the field of vehicle braking. The system comprises a main power supply module, a redundant power supply module, a power supply switching module, an EPB emergency braking module and a vehicle control unit, and the main power supply module and the redundant power supply module are electrically connected with the power supply switching module; the power supply switching module is electrically connected with the EPB emergency braking module; and the main power supply module, the redundant power supply module, the power supply switching module and the vehicle control unit are respectively in communication connection with the EPB emergency braking module. According to the invention, the emergency braking system of the unmanned logistics vehicle can still be normally started under the condition of power failure, so that the driving safety of the unmanned vehicle is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle braking, and in particular, the present invention relates to an emergency braking system, method and vehicle for an unmanned logistics vehicle. Background Art

[0002] With the rapid development of driverless technology, its safety issues are increasingly attracting people's attention.

[0003] The emergency brake device of the unmanned logistics vehicle is an important part of ensuring driving safety. The EPB is the main actuator of the emergency brake, and its stability and reliability directly affect the safety performance of the unmanned vehicle. However, in actual applications, due to power failure of the unmanned vehicle, the EPB may not be able to start, thus affecting the emergency braking effect of the unmanned vehicle.

[0004] The reference document (CN118282021A) provides a redundant power supply circuit, a controller and a vehicle. The redundant power supply circuit is used to power the domain controller of the vehicle, including a first power supply, a second power supply and a redundant power supply distribution circuit, wherein the output ends of the first power supply and the second power supply are respectively connected to the redundant power supply distribution circuit; wherein the redundant power supply distribution circuit is used for current equalization output and power switching of the first power supply and the second power supply. By adopting a redundant power supply circuit in the domain controller of the vehicle, the high reliability requirements for the controller in certain harsh working scenarios are met, thereby ensuring the safe driving of the vehicle.

[0005] From the above-mentioned comparative documents, it can be seen that the power redundancy mechanism is an effective means to solve power failures, but there is no relevant configuration and control strategy in the field of emergency braking of unmanned logistics vehicles. Therefore, it is necessary to design a power redundancy mechanism to ensure that the emergency braking system of the unmanned logistics vehicle can still start normally in the event of a power failure, thereby ensuring the driving safety of the unmanned vehicle. Summary of the invention

[0006] The present invention aims to overcome the deficiencies of the prior art and proposes an unmanned logistics vehicle emergency braking system, method and vehicle to achieve the following objectives: to ensure that in the event of a power failure, the unmanned logistics vehicle emergency braking system can still be started normally, thereby ensuring the driving safety of the unmanned vehicle.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] An emergency braking system for an unmanned logistics vehicle, the system comprising a main power module, a redundant power module, a power switching module, an EPB emergency braking module, and a vehicle controller, wherein the main power module and the redundant power module are electrically connected to the power switching module, respectively; the power switching module is electrically connected to the EPB emergency braking module; the main power module, the redundant power module, the power switching module, and the vehicle controller are also communicatively connected to the EPB emergency braking module, respectively.

[0009] Preferably, the power switching module includes a switching control unit, a power bus, a first relay, and a second relay, wherein the output end of the main power module is electrically connected to the power bus through the normally closed contact of the first relay; the output end of the redundant power module is electrically connected to the power bus through the normally open contact of the second relay; the switching control unit is respectively connected to the coil control ends of the first relay and the second relay, and the switching control unit is also communicatively connected to the EPB emergency braking module; the power bus is electrically connected to the EPB emergency braking module.

[0010] Preferably, the switching control unit starts power switching after receiving the power switching signal of the EPB emergency brake module, first controlling the normally open contact of the second relay to close and then disconnecting the normally closed contact of the first relay.

[0011] Preferably, the main power module includes a main power battery pack, a first battery management system, and a voltage converter, wherein the first battery management system is connected to the main power battery pack for monitoring the status of the main power battery pack and sending it to the EPB emergency braking module; the output end of the main power battery pack serves as the output end of the main power module and is electrically connected to the power switching module through the voltage converter.

[0012] Preferably, the voltage converter adopts a bidirectional DC / DC converter, which is used to step down the output high voltage of the main power battery pack to the working low voltage of the EPB emergency braking module when working in the forward direction; when working in the reverse direction, it is used to isolate the output voltage of the main power module and the output voltage of the redundant power module to avoid circulating current.

[0013] Preferably, the redundant power supply module includes a redundant battery pack and a second battery management system, wherein the second battery management system is connected to the redundant battery pack for monitoring the status of the redundant battery pack and sending it to the EPB emergency braking module; the output end of the redundant battery pack is electrically connected to the power switching module as the output end of the redundant power supply module.

[0014] Preferably, the EPB emergency braking module includes an electronic control unit, an electric actuator, and a sensor unit, wherein the electronic control unit is respectively connected to the electric actuator, the sensor unit, and the vehicle controller; the electronic control unit, the electric actuator, and the sensor unit are all powered by the power supply selected by the power switching module.

[0015] Preferably, the sensor unit includes a vehicle speed sensor, an acceleration sensor, and a brake pedal position sensor.

[0016] The present application also proposes an unmanned logistics vehicle emergency braking method, which is applied to the above-mentioned unmanned logistics vehicle emergency braking system, including:

[0017] Step S1: The vehicle is powered on, the main power module works normally, and the redundant power module is in a waiting state;

[0018] Step S2: When emergency braking is required, the vehicle controller sends an emergency braking signal to the electronic control unit of the EPB emergency braking module, and the electronic control unit drives the electric actuator to apply braking force to the wheel according to the emergency braking signal and in combination with data from the sensor unit;

[0019] Step S3: During the emergency braking process, when the first battery management system of the main power module detects that the main power module is abnormal, the first battery management system generates and sends a fault signal to the electronic control unit of the EPB emergency braking module;

[0020] Step S4, after receiving the fault signal, the electronic control unit sends a power switching signal to the switching control unit of the power switching module;

[0021] Step S5: After receiving the power switching signal, the switching control unit sends a control signal to sequentially control the normally open contact of the second relay connected to the redundant power module to close and the normally closed contact of the first relay connected to the main power module to open;

[0022] Step S6: After the switching is completed, the redundant power supply module is activated. At this time, after the second battery management system of the redundant power supply module sends a switching completion signal to the electronic control unit of the EPB emergency brake module, the electronic control unit continues to drive the electric actuator to apply braking force to the wheel to complete braking.

[0023] At the same time, the present application also proposes a vehicle, which includes the above-mentioned unmanned logistics vehicle emergency braking system.

[0024] The technical effects of the present invention are:

[0025] Improve safety: When the main power system fails or the power is interrupted, it can quickly switch to the redundant power supply to ensure the normal operation of the emergency braking system and effectively avoid safety accidents caused by brake failure.

[0026] Enhanced reliability: By adding redundant power modules and optimizing the control strategy of the emergency braking system, the overall reliability of the unmanned logistics vehicle's power system and braking system has been significantly improved.

[0027] Improve emergency response capabilities: When a power failure occurs, the power supply can be quickly switched, buying valuable time for safe parking of the vehicle or intervention of maintenance personnel.

[0028] Reduce maintenance costs: By reducing the number of vehicle shutdowns and repairs due to power failures, the overall maintenance costs of unmanned logistics vehicles are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of an emergency braking system for an unmanned logistics vehicle according to an embodiment of the present invention;

[0030] Figure 2 The present invention is a flowchart of an emergency braking method for an unmanned logistics vehicle according to an embodiment of the present invention.

[0031] Figure 1 In the middle: 1 is the main power module, 2 is the redundant power module, 3 is the power switching module, 4 is the EPB emergency brake module, and 5 is the vehicle controller. DETAILED DESCRIPTION

[0032] The following is a further detailed description of the specific implementation of the present invention by describing the embodiments with reference to the accompanying drawings, with the purpose of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and to facilitate its implementation. In order to make the technical solution of the present invention clearer, the present invention is explained by the following embodiments.

[0033] It should be noted that the words "first", "second", etc. mentioned in the present application are only for the convenience of describing the technical solution to distinguish different components, and are not intended to limit the present application. In addition, without specific reference (for example, specific reference to "electrical connection", "communication connection", etc.), the "connection" mentioned in the present application includes not only electrical connections for power transmission and electronic devices, but also communication connections for data transmission and signal transmission.

[0034] In this embodiment, in order to ensure the transmission speed and stability of the data signal, the signal transmission adopts the CAN bus. During the specific implementation, the signal transmission method can be flexibly selected according to the actual situation.

[0035] When a power failure occurs in an unmanned logistics vehicle, the EPB (electronic parking brake system) may fail to start or have insufficient braking force due to insufficient power supply, thus affecting the emergency braking effect of the unmanned vehicle.

[0036] To solve the above problems, this embodiment proposes an emergency braking system for an unmanned logistics vehicle. Figure 1 The system structure diagram shown is used for specific description. The unmanned logistics vehicle emergency braking system of this embodiment includes a main power module 1, a redundant power module 2, a power switching module 3, an EPB emergency braking module 4, and a vehicle controller 5, wherein the main power module 1 and the redundant power module 2 are electrically connected to the power switching module 3 respectively; the power switching module 3 is electrically connected to the EPB emergency braking module 4; the main power module 1, the redundant power module 2, the power switching module 3, and the vehicle controller 5 are also respectively connected to the EPB emergency braking module 4 in communication.

[0037] Specifically, the main power module 1 is used to provide stable power supply to various electrical equipment of the unmanned logistics vehicle under normal working conditions, and in this embodiment, it mainly supplies power to the EPB emergency brake module 4. The main power module 1 includes a main power battery pack, a first battery management system, and a voltage converter, wherein the first battery management system (BMS) is connected to the main power battery pack, and is used to monitor the status of the main power battery pack and send it to the EPB emergency brake module 4. In this embodiment, all battery management systems are integrated with battery status monitoring equipment such as voltage sensors, current sensors, and temperature sensors, which can realize real-time monitoring of all aspects of the battery, which will not be repeated later. The output end of the main power battery pack is electrically connected to the power switching module 3 through the voltage converter as the output end of the main power module 1.

[0038] The redundant power supply module 1 of this embodiment is used as a redundant EPB emergency brake module 4 when the main power supply module 1 fails, is low on power, or encounters other abnormal situations. The redundant power supply module 1 includes a redundant battery pack and a second battery management system, wherein the second battery management system is connected to the redundant battery pack to monitor the status of the redundant battery pack and send it to the EPB emergency brake module 4; the output end of the redundant battery pack is electrically connected to the power switching module 3 as the output end of the redundant power supply module 2. In specific implementation, the redundant battery pack can use a low-voltage battery between 12V and 48V, which can supply power to the EPB emergency brake module 4 without reducing the voltage again, thereby reducing costs. At the same time, compared with the power battery pack of an unmanned vehicle, it is smaller in size and lighter in weight, making it easier to install in an unmanned vehicle.

[0039] The power switching module 3 of this embodiment is used to switch to the redundant power supply module for power supply when the main power supply module fails. Specifically, the power switching module 3 includes a switching control unit, a power bus, a first relay, and a second relay, wherein the output end of the main power supply module is electrically connected to the power bus through the normally closed contact of the first relay; the output end of the redundant power supply module is electrically connected to the power bus through the normally open contact of the second relay; the switching control unit is respectively connected to the coil control ends of the first relay and the second relay, and the switching control unit is also communicatively connected to the EPB emergency brake module; the power bus is electrically connected to the EPB emergency brake module. In order to increase the switching speed of the power supply and ensure timely power supply, the switching control unit can select highly integrated control chips such as microcontrollers MCU and central processing units CPU, thereby improving control efficiency.

[0040] The working principle of the power switching module 3 is as follows: the switching control unit starts power switching after receiving the power switching signal of the EPB emergency braking module 4, first controlling the normally open contacts of the second relay to close and then disconnecting the normally closed contacts of the first relay, thereby achieving continuous and uninterrupted power supply to the EPB emergency braking module 4 to ensure the normal braking of the unmanned vehicle and thus the driving safety of the unmanned vehicle.

[0041] In actual use, when the main power module 1 fails and the power switching module 3 switches normally, it is obvious that in order to ensure the continuity of the switching, the main power module 1 and the redundant power module 2 simultaneously supply power to the EPB emergency brake module 4 to form a loop during the power switching. In this case, due to the failure of the main power module 1 or insufficient power, the output voltages of the main power module 1 and the redundant power module 2 will be different, resulting in a circulating current. In order to avoid damage to the power module caused by the circulating current, in this embodiment, the voltage converter of the main power module 1 adopts a bidirectional DC / DC converter. The bidirectional DC / DC converter is used to step down the output high voltage of the main power battery pack to the working low voltage of the EPB emergency brake module when working in the forward direction; when working in the reverse direction, it is used to isolate the output voltage of the main power module and the output voltage of the redundant power module to avoid the circulating current.

[0042] The EPB emergency brake module 4 of this embodiment is used to ensure that when the main power fails, the fault signal of the main power module 1 is received, and an instruction is issued to the power switching module 3 so that the redundant power module 2 can immediately supply power to the braking system to ensure the normal operation of the braking system. Specifically, the EPB emergency brake module 4 includes an electronic control unit (ECU), an electric actuator, and a sensor unit, wherein the electronic control unit is respectively connected to the electric actuator, the sensor unit, and the vehicle controller; the electronic control unit, the electric actuator, and the sensor unit are all powered by the power supply selected by the power switching module. Among them, the sensor unit is used to detect the status and environmental information of the vehicle, including a vehicle speed sensor, an acceleration sensor, a brake pedal position sensor, a radar, a high-precision camera, an infrared sensor, etc.

[0043] The electronic control unit is responsible for receiving signals from the sensor unit and the emergency brake signal from the vehicle controller. In emergency braking, based on the received sensor information, such as the current vehicle speed, acceleration, and brake pedal position, the electronic control unit can calculate the braking force required and output the corresponding control signal to the electric actuator.

[0044] The electric actuator controls the working state of the brake according to the control signal of the electronic control unit. The electric actuator usually adopts a combination of a motor and a screw mechanism. The rotation of the motor drives the screw to move the piston of the brake outward or inward, thereby achieving braking or release.

[0045] At the same time, this embodiment also proposes an unmanned logistics vehicle emergency braking method, which is applied to the above-mentioned unmanned logistics vehicle emergency braking system, such as Figure 2 As shown, the method comprises the following steps:

[0046] Step S1: The vehicle is powered on, the main power module works normally, and the redundant power module is in a waiting state.

[0047] Step S2: When emergency braking is required, the vehicle controller sends an emergency braking signal to the electronic control unit of the EPB emergency braking module. The electronic control unit drives the electric actuator to apply braking force to the wheel according to the emergency braking signal and in combination with data from the sensor unit.

[0048] Step S3: During the emergency braking process, when the first battery management system of the main power module detects that the main power module is abnormal, the first battery management system generates and sends a fault signal to the electronic control unit of the EPB emergency braking module. If the first battery management system of the main power module detects that the output voltage or output current or battery temperature of the main power battery pack of the main power module exceeds the preset voltage, current or temperature threshold range, the main power module is considered to be abnormal; at the same time, when the remaining power (SOC) of the main power battery pack is lower than the preset power threshold (which can be set according to the power consumed to complete an emergency braking, under normal circumstances, the SOC of the main power battery pack must ensure that at least one emergency braking can be completed), the main power module is also considered to be abnormal.

[0049] Step S4, after receiving the fault signal, the electronic control unit sends a power switching signal to the switching control unit of the power switching module. The electronic control unit can also determine whether the remaining power of the main power module can meet the emergency braking requirement in combination with the data of the sensor unit. The electronic control unit can calculate the braking force requirement of the current vehicle in combination with the current vehicle speed, acceleration, brake pedal position and other data; combined with the historical braking data of the current vehicle, the electronic control unit can obtain the relationship between the braking power consumption and the braking force. When the remaining power of the main power module does not meet the emergency braking requirement, the electronic control unit immediately sends a power switching signal to the switching control unit of the power switching module. When the remaining power of the main power module can meet the emergency braking requirement, the electronic control unit can optionally send a power switching signal to the switching control unit of the power switching module after the braking is completed, or send a signal to the vehicle controller, and the vehicle controller then feeds back to the user for selection.

[0050] Step S5: After receiving the power switching signal, the switching control unit sends a control signal to sequentially control the normally open contact of the second relay connected to the redundant power module to close, and the normally closed contact of the first relay connected to the main power module to open.

[0051] Step S6: After the switching is completed, the redundant power supply module is activated. At this time, after the second power management system of the redundant power supply module sends a switching completion signal to the electronic control unit of the EPB emergency brake module, the electronic control unit continues to drive the electric actuator to apply braking force to the wheel to complete braking.

[0052] At the same time, the present application also proposes a vehicle, which includes the above-mentioned unmanned logistics vehicle emergency braking system.

[0053] The beneficial effects of this embodiment can be summarized as follows:

[0054] Improve safety: When the main power system fails or the power is interrupted, it can quickly switch to the redundant power supply to ensure the normal operation of the emergency braking system and effectively avoid safety accidents caused by brake failure.

[0055] Enhanced reliability: By adding redundant power modules and optimizing the control strategy of the emergency braking system, the overall reliability of the unmanned logistics vehicle's power system and braking system has been significantly improved.

[0056] Improve emergency response capabilities: When a power failure occurs, the power supply can be quickly switched, buying valuable time for safe parking of the vehicle or intervention of maintenance personnel.

[0057] Reduce maintenance costs: By reducing the number of vehicle shutdowns and repairs due to power failures, the overall maintenance costs of unmanned logistics vehicles are reduced.

[0058] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An emergency braking system for an unmanned logistics vehicle, characterized in that: The system includes a main power module, a redundant power module, a power switching module, an EPB emergency brake module, and a vehicle controller, wherein the main power module and the redundant power module are electrically connected to the power switching module respectively; the power switching module is electrically connected to the EPB emergency brake module; the main power module, the redundant power module, the power switching module, and the vehicle controller are also respectively communicatively connected to the EPB emergency brake module.

2. The unmanned logistics vehicle emergency braking system according to claim 1, characterized in that: The power switching module includes a switching control unit, a power bus, a first relay, and a second relay, wherein the output end of the main power module is electrically connected to the power bus through the normally closed contact of the first relay; the output end of the redundant power module is electrically connected to the power bus through the normally open contact of the second relay; the switching control unit is respectively connected to the coil control ends of the first relay and the second relay, and the switching control unit is also communicatively connected to the EPB emergency braking module; the power bus is electrically connected to the EPB emergency braking module.

3. The unmanned logistics vehicle emergency braking system according to claim 2, characterized in that: The switching control unit starts power switching after receiving the power switching signal of the EPB emergency brake module, first controlling the normally open contact of the second relay to close and then disconnecting the normally closed contact of the first relay.

4. An emergency braking system for an unmanned logistics vehicle according to claim 2 or 3, characterized in that: The main power module includes a main power battery pack, a first battery management system, and a voltage converter, wherein the first battery management system is connected to the main power battery pack to monitor the status of the main power battery pack and send it to the EPB emergency braking module; the output end of the main power battery pack serves as the output end of the main power module and is electrically connected to the power switching module through the voltage converter.

5. The unmanned logistics vehicle emergency braking system according to claim 4, characterized in that: The voltage converter adopts a bidirectional DC / DC converter, which is used to step down the output high voltage of the main power battery pack to the working low voltage of the EPB emergency brake module when working in the forward direction; when working in the reverse direction, it is used to isolate the output voltage of the main power module and the output voltage of the redundant power module to avoid circulating current.

6. An emergency braking system for an unmanned logistics vehicle according to claim 2 or 3, characterized in that: The redundant power supply module includes a redundant battery pack and a second battery management system, wherein the second battery management system is connected to the redundant battery pack to monitor the status of the redundant battery pack and send it to the EPB emergency braking module; the output end of the redundant battery pack is electrically connected to the power switching module as the output end of the redundant power supply module.

7. The unmanned logistics vehicle emergency braking system according to claim 2, characterized in that: The EPB emergency brake module includes an electronic control unit, an electric actuator, and a sensor unit, wherein the electronic control unit is connected to the electric actuator, the sensor unit, and the vehicle controller respectively; the electronic control unit, the electric actuator, and the sensor unit are all powered by the power supply selected by the power switching module.

8. The unmanned logistics vehicle emergency braking system according to claim 7, characterized in that: The sensor unit includes a vehicle speed sensor, an acceleration sensor, and a brake pedal position sensor.

9. An emergency braking method for an unmanned logistics vehicle, characterized in that: The method is applied to an emergency braking system for an unmanned logistics vehicle according to any one of claims 1 to 8, comprising: Step S1: The vehicle is powered on, the main power module works normally, and the redundant power module is in a waiting state; Step S2: When emergency braking is required, the vehicle controller sends an emergency braking signal to the electronic control unit of the EPB emergency braking module, and the electronic control unit drives the electric actuator to apply braking force to the wheel according to the emergency braking signal and in combination with data from the sensor unit; Step S3: During the emergency braking process, when the first battery management system of the main power module detects that the main power module is abnormal, the first battery management system generates and sends a fault signal to the electronic control unit of the EPB emergency braking module; Step S4, after receiving the fault signal, the electronic control unit sends a power switching signal to the switching control unit of the power switching module; Step S5: After receiving the power switching signal, the switching control unit sends a control signal to sequentially control the normally open contact of the second relay connected to the redundant power module to close and the normally closed contact of the first relay connected to the main power module to open; Step S6: After the switching is completed, the redundant power supply module is activated. At this time, after the second battery management system of the redundant power supply module sends a switching completion signal to the electronic control unit of the EPB emergency brake module, the electronic control unit continues to drive the electric actuator to apply braking force to the wheel to complete braking.

10. A vehicle, characterized in that: The vehicle includes an unmanned logistics vehicle emergency braking system according to any one of claims 1-8.

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