An unmanned vehicle parking and charging system and method based on UWB technology

Abstract

The application discloses an unmanned vehicle parking and charging system and method based on UWB technology, and belongs to the technical field of unmanned vehicle parking and charging. The system comprises a vehicle-mounted execution unit, a field end positioning and charging unit and a scheduling control unit; the UWB technology is combined with a fusion algorithm to realize centimeter-level positioning, completely solve the problem of insufficient positioning accuracy in the prior art, improve the charging docking success rate, reduce the number of repeated docking, and improve the charging efficiency; in the process that the unmanned vehicle drives to the charging station for parking and charging, different distances between the unmanned vehicle and the charging station are adopted to adopt a phased strategy, corresponding algorithms and rules are designed to control the driving of the unmanned vehicle, the unmanned vehicle drives to the charging station in the mode of first fast and then slow, and the unmanned vehicle is adapted to pose adjustment in the slow state, so that the docking success rate is improved, the parking and charging efficiency is improved, and the anti-interference capability is improved through the phased strategy, and the adaptation scene is widened.

Description

Technical Field

[0001] This invention relates to an unmanned vehicle parking and charging system and method based on UWB technology, belonging to the field of unmanned vehicle parking and charging technology. Background Technology

[0002] With the rapid development of intelligent logistics and unmanned technology, unmanned vehicles have been widely used in closed parks, warehouse sorting, underground parking lots, and other scenarios. Their autonomous operation capability has become the core for improving efficiency and reducing costs. Automatic charging at the docking point of unmanned vehicles is a crucial link in their fully autonomous operation and directly affects operational continuity. Currently, the docking and charging of unmanned vehicles mostly uses technologies such as GPS, BLE, ultrasonic radar, or visual recognition for positioning and docking. However, these technologies have many limitations in practical applications. GPS, or the Global Positioning System, has an accuracy of 2 to 5 meters in open environments, far below the centimeter-level accuracy required for charging docking. In indoor environments, underground garages, and high-density parks, signal reflection causes positioning jumps. If there are obstructions near the charging station, such as roofs and metal structures, GPS becomes completely ineffective. It is more suitable for coarse outdoor positioning and not for precise docking in unmanned vehicle docking and charging scenarios. BLE, or Bluetooth Low Energy, is affected by multipath propagation, absorption, temperature, and humidity, resulting in ranging errors of 1 to 3 meters. Positioning beyond 10 meters is unreliable, making it impossible to guide autonomous vehicles in advance; it can only provide rough near-field guidance and is insufficient for millisecond- or centimeter-level charging docking. Ultrasonic radar is susceptible to surface interference; tilted charging pile surfaces and sound-absorbing materials can cause echo loss. Furthermore, multiple ultrasonic sensors operating simultaneously can interfere with each other, resulting in an effective ranging range generally less than 5 meters and a narrow guidance window. While suitable for low-speed collision avoidance, it is not ideal for precise docking and positioning. Visual recognition is sensitive to light; strong backlight, low light, shadows, and reflections can lead to recognition failures. It is suitable for structured, well-lit indoor environments but has poor robustness to outdoor or dynamic lighting conditions. Inaccurate positioning necessitates multiple adjustments, leading to longer docking times and ultimately lower charging efficiency.

[0003] In summary, existing technologies still suffer from drawbacks such as low positioning accuracy, low charging efficiency, and weak adaptability to different scenarios, making it difficult to meet the requirements of fully autonomous operation. Summary of the Invention

[0004] The purpose of this invention is to provide an unmanned vehicle docking and charging system and method based on UWB technology, which solves the defects of low positioning accuracy, low charging efficiency and weak scene adaptability in the existing technology.

[0005] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides an unmanned vehicle parking and charging system based on UWB technology, including an on-board execution unit, a field-end positioning and charging unit, and a scheduling and control unit; The vehicle-mounted execution unit includes a UWB positioning tag, a vehicle-mounted main control module, and a charging interface module. The charging interface module is used to connect the field-end positioning and charging unit to obtain power. The UWB positioning tag is installed on the unmanned vehicle near the charging interface module and is used to send pulse signals to the UWB anchor array. The vehicle-mounted main control module is used to send charging requests to the scheduling control unit and also to receive scheduling instructions and control the unmanned vehicle to drive accordingly. The field-end positioning and charging unit includes a UWB anchor array, a UWB base station gateway, an automatic charging mechanism, multiple charging stations, and a charging control module. The UWB anchor array is used to convert pulse signals into positioning data and send them to the UWB base station gateway. The UWB base station gateway is used to forward the positioning data to the scheduling control unit and the automatic charging mechanism. The automatic charging mechanism is used to move to the location of the charging interface module based on the positioning data, and also to connect the charging gun on the charging station to the charging interface in the charging interface module. The charging control module is used to realize intelligent control during the charging process. The scheduling and control unit is used to allocate an available charging station to the unmanned vehicle when it receives a charging request. It plans the optimal path from the unmanned vehicle to the available charging station based on the positioning data and sends the optimal path to the on-board main control module in the form of a scheduling command.

[0006] Furthermore, the charging interface module includes a charging interface, an electromagnetic locking mechanism, and a status detection sensor; The charging interface is used to connect the field-end positioning and the charging unit to obtain electrical energy; The status detection sensor is connected to the charging interface and the electromagnetic locking mechanism respectively, and is used to detect the connection status of the charging interface and the locking status of the electromagnetic locking mechanism and send them to the vehicle main control module. The electromagnetic locking mechanism is connected to the charging interface and also communicates with the vehicle main control module. In response to the charging interface being connected and the electromagnetic locking mechanism being unlocked, the vehicle main control module controls the electromagnetic locking mechanism to lock the charging interface.

[0007] Furthermore, the vehicle-mounted execution unit also includes an attitude detection module, which is used to detect the real-time attitude data of the unmanned vehicle and send it to the vehicle-mounted main control module. The real-time attitude data includes the real-time vehicle yaw angle, the real-time vehicle pitch angle and the real-time vehicle roll angle. The onboard main control module is also used to adjust the attitude of the unmanned vehicle according to scheduling instructions and real-time attitude data.

[0008] Furthermore, the scheduling control unit is also used to monitor the driving path of the unmanned vehicle as it drives toward an empty charging station, and adjust the driving path of the unmanned vehicle based on real-time positioning data when the unmanned vehicle deviates from the optimal path.

[0009] Furthermore, the automatic charging mechanism includes a driving unit, a base, a six-degree-of-freedom robotic arm, a force feedback sensor, and a visual assistance camera; The driving unit is located at the bottom of the base and is used to drive the automatic charging mechanism to move; A six-degree-of-freedom robotic arm is mounted on the base and connected to a scheduling and control unit. The scheduling and control unit is also connected to force feedback sensors and visual auxiliary cameras. There are six force feedback sensors, which are respectively installed at the six wrists of the six-degree-of-freedom robotic arm. The visual auxiliary cameras are used to collect the position information of the charging gun and the charging interface and send it to the scheduling and control unit. The force feedback sensors are used to collect the contact force at the wrists of the six-degree-of-freedom robotic arm and send it to the scheduling and control unit. The scheduling and control unit generates robotic arm control commands based on the position information of the charging gun and the charging interface and the contact force and sends them to the six-degree-of-freedom robotic arm. The six-degree-of-freedom robotic arm docks the charging gun and the charging interface according to the robotic arm control commands.

[0010] Secondly, the present invention provides a method for parking and charging an unmanned vehicle based on the unmanned vehicle parking and charging system according to any one of the first aspects, characterized in that it includes: In response to the unmanned vehicle's battery level falling below a preset threshold, the onboard main control module sends a charging request to the dispatch control unit. The scheduling and control unit obtains the location data of the unmanned vehicle and the status information of each charging station. Based on the status information of each charging station, it allocates an available charging station to the unmanned vehicle. Based on the location data of the unmanned vehicle, it plans the optimal path from the unmanned vehicle to the available charging station and sends the optimal path to the on-board main control module in the form of a scheduling command. The onboard main control module controls the unmanned vehicle to drive along the optimal path to an available charging station according to the scheduling instructions until the unmanned vehicle completes parking. During this process, if the distance between the unmanned vehicle and the available charging station is greater than a first distance threshold, the onboard main control module uses an arrival time difference algorithm to control the unmanned vehicle to travel at a first speed. If the distance between the unmanned vehicle and the available charging station is greater than a second distance threshold but not greater than the first distance threshold, the onboard main control module uses a time-of-flight and arrival time difference fusion algorithm to control the unmanned vehicle to travel at a second speed. If the distance between the unmanned vehicle and the available charging station is not greater than the second distance threshold, the onboard main control module uses a time-of-flight algorithm to control the unmanned vehicle to travel at a third speed. Wherein, the first distance threshold is greater than the second distance threshold, the first speed is greater than the second speed, and the second speed is greater than the third speed. The automatic charging mechanism moves to the charging interface module based on the positioning data of the unmanned vehicle and connects the charging gun and the charging interface. The unmanned vehicle is charged under the control of the charging control module.

[0011] Furthermore, when the docking alignment error between the unmanned vehicle and the endpoint of the optimal path does not exceed the third distance threshold, and the vehicle body posture deviation does not exceed the preset angle threshold, the unmanned vehicle completes the docking, and the on-board main control module controls the parking brake of the unmanned vehicle. The vehicle attitude deviation includes vehicle yaw angle deviation, vehicle pitch angle deviation, and vehicle roll angle deviation. The vehicle yaw angle deviation is the absolute value of the difference between the real-time vehicle yaw angle and the preset vehicle yaw angle. The vehicle pitch angle deviation is the absolute value of the difference between the real-time vehicle pitch angle and the preset vehicle pitch angle. The vehicle roll angle deviation is the absolute value of the difference between the real-time vehicle roll angle and the preset vehicle roll angle.

[0012] Furthermore, during the process of the vehicle-mounted main control module using the time-of-flight and time-of-arrival fusion algorithm to control the unmanned vehicle to travel at the second speed, the method also includes: the attitude detection module detecting the real-time attitude data of the unmanned vehicle and sending it to the vehicle-mounted main control module; the vehicle-mounted main control module adjusting the attitude of the unmanned vehicle once according to the scheduling instructions and the real-time attitude data. During the process of the vehicle-mounted main control module using the time-of-flight algorithm to control the unmanned vehicle to travel at the third speed, the system also includes: an attitude detection module that detects the real-time attitude data of the unmanned vehicle and sends it to the vehicle-mounted main control module; and the vehicle-mounted main control module, based on the scheduling instructions and the real-time attitude data, combined with Kalman filtering and PID control, making secondary adjustments to the attitude of the unmanned vehicle.

[0013] Furthermore, the automatic charging mechanism moves to the charging interface module location based on the unmanned vehicle's positioning data, and docks the charging gun and the charging interface, including: The automatic charging mechanism moves to the charging interface module based on the positioning data of the unmanned vehicle, and uses a six-degree-of-freedom robotic arm to dock the charging gun and the charging interface once. A visual auxiliary camera collects the position information of the charging gun and charging interface and sends it to the scheduling control unit. A force feedback sensor collects the contact force at the wrist of the six-degree-of-freedom robotic arm and sends it to the scheduling control unit. The scheduling control unit generates robotic arm control commands based on the position information of the charging gun and charging interface and the contact force and sends them to the six-degree-of-freedom robotic arm. The six-degree-of-freedom robotic arm performs a secondary docking of the charging gun and charging interface according to the robotic arm control commands, and maintains the contact force not exceeding the contact force threshold during the secondary docking process, until the center position deviation of the charging gun and charging interface is not greater than the fourth distance threshold, thus completing the docking of the charging gun and charging interface.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention provides an unmanned vehicle (UWB) docking and charging system and method based on UWB technology. It employs UWB technology combined with a fusion algorithm to achieve centimeter-level positioning, enabling docking alignment errors of no more than 4cm and charging docking accuracy of no more than 3cm. This completely solves the problem of insufficient positioning accuracy in existing technologies, eliminating the need for manual docking assistance, improving the charging docking success rate, reducing the number of repeated docking attempts, and thus increasing charging efficiency. Through the coordinated operation of the onboard execution unit, the field-end positioning and charging unit, and the scheduling control unit, the entire process of docking, docking, and charging is automated, shortening charging preparation time, improving the operational continuity of the unmanned vehicle, and meeting the needs of high-frequency operation. The system allows the unmanned vehicle to dock at the charging station. During the charging process, a phased strategy is adopted to address the varying distances between the unmanned vehicle and the charging station. Corresponding algorithms and rules are designed to control the unmanned vehicle's movement. A first distance threshold is set higher than a second distance threshold, a first speed is set higher than a second speed, and a second speed is set higher than a third speed. This allows the unmanned vehicle to approach the charging station in a fast-then-slow manner, adapting to attitude adjustments at slower speeds. This improves the docking success rate and enhances parking and charging efficiency. Furthermore, the phased strategy enhances anti-interference capabilities, adapting to complex scenarios such as indoor, underground, and warehouse environments. It supports simultaneous charging of multiple vehicles and compatibility with different types of unmanned vehicles, demonstrating strong versatility and wide applicability to various low-speed unmanned vehicle scenarios. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an unmanned vehicle docking and charging system based on UWB technology provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the deployment of the UWB anchor array provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the charging preparation process for an unmanned vehicle provided in an embodiment of the present invention. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0017] Example 1

[0018] like Figure 1 As shown, this embodiment provides an unmanned vehicle parking and charging system based on UWB technology, including an on-board execution unit, a field-end positioning and charging unit, and a scheduling and control unit; The vehicle-mounted execution unit includes a UWB positioning tag, a vehicle-mounted main control module, and a charging interface module. The charging interface module is used to connect the field-end positioning and charging unit to obtain power. The UWB positioning tag is installed on the unmanned vehicle near the charging interface module and is used to send pulse signals to the UWB anchor array. The vehicle-mounted main control module is used to send charging requests to the scheduling control unit and also to receive scheduling instructions and control the unmanned vehicle to drive accordingly. The field-end positioning and charging unit includes a UWB anchor array, a UWB base station gateway, an automatic charging mechanism, multiple charging stations, and a charging control module. The UWB anchor array is used to convert pulse signals into positioning data and send them to the UWB base station gateway. The UWB base station gateway is used to forward the positioning data to the scheduling control unit and the automatic charging mechanism. The automatic charging mechanism is used to move to the location of the charging interface module based on the positioning data, and also to connect the charging gun on the charging station to the charging interface in the charging interface module. The charging control module is used to realize intelligent control during the charging process. The scheduling and control unit is used to allocate an available charging station to the unmanned vehicle when it receives a charging request. It plans the optimal path from the unmanned vehicle to the available charging station based on the positioning data and sends the optimal path to the on-board main control module in the form of a scheduling command.

[0019] This invention employs UWB technology combined with a fusion algorithm to achieve centimeter-level positioning, enabling docking alignment errors of no more than 4cm and charging docking accuracy of no more than 3cm. This completely solves the problem of insufficient positioning accuracy in existing technologies, eliminating the need for manual docking assistance, improving charging docking success rates, reducing the number of repeated docking attempts, and thus increasing charging efficiency. Through the coordinated operation of the onboard execution unit, the field-end positioning and charging unit, and the scheduling control unit, the entire process of docking, docking, and charging is automated, shortening charging preparation time, improving the operational continuity of the unmanned vehicle, and meeting the needs of high-frequency operation. During the process of the unmanned vehicle driving to the charging station for docking and charging, [the invention further addresses the issue of insufficient positioning accuracy in existing technologies]. To address the varying distances between the vehicle and the charging station, a phased strategy is employed. Corresponding algorithms and rules are designed to control the autonomous vehicle's movement. First distance thresholds are set higher than second distance thresholds, first speeds are higher than second speeds, and second speeds are higher than third speeds. This allows the autonomous vehicle to approach the charging station at a faster speed initially, followed by a slower one, to adapt to attitude adjustments during slower speeds. This improves docking success rates and increases parking and charging efficiency. Furthermore, this phased strategy enhances anti-interference capabilities, adapting to complex scenarios such as indoor, underground, and warehouse environments. It supports simultaneous charging of multiple vehicles, compatibility with different types of autonomous vehicles, and strong versatility, making it widely applicable to various low-speed autonomous vehicle scenarios.

[0020] Example 2

[0021] This embodiment provides an unmanned vehicle parking and charging system based on UWB technology, including an on-board execution unit, a field-end positioning and charging unit, and a scheduling and control unit.

[0022] The onboard actuator is deployed on the unmanned vehicle and includes a UWB positioning tag, an onboard main control module, an attitude detection module, a wireless communication module, and a charging interface module. UWB is an abbreviation for Ultra-Wideband.

[0023] The UWB positioning tag employs a dual-antenna design and supports a time-of-flight and time-of-arrival fusion algorithm, achieving a positioning accuracy of ≤10cm and a data update frequency of ≥50Hz. It is installed on the front top of the unmanned vehicle, near the charging port module, avoiding obstruction by the vehicle body to improve positioning accuracy and thus provide a foundation for subsequent precise docking. The association or data interaction between the UWB positioning tag and other modules or units is described as follows: It is used to send pulse signals to the UWB anchor array.

[0024] The onboard main control module uses an automotive-grade MCU chip, responsible for receiving scheduling instructions, processing sensor data, and controlling vehicle movement and attitude adjustment. The association and data interaction between the onboard main control module and other modules or units are described as follows: it is used to send charging requests to the scheduling control unit; it is also used to receive scheduling instructions and control the autonomous vehicle's movement accordingly; and it is used to adjust the autonomous vehicle's attitude based on the scheduling instructions issued by the scheduling control unit and the real-time attitude data sent by the attitude detection module.

[0025] The attitude detection module employs a 6-axis IMU (Inertial Measurement Unit) to detect the vehicle's yaw, pitch, and roll angles in real time, providing data support for attitude adjustment. The relationship and data interaction between the attitude detection module and other modules or units are described below: It detects the real-time attitude data of the autonomous vehicle and sends it to the onboard main control module. The real-time attitude data includes the real-time yaw, pitch, and roll angles.

[0026] The wireless communication module adopts the Wi-Fi 6 communication protocol with a transmission delay of ≤20ms, ensuring real-time interaction between modules or units, including real-time interaction of control commands and various status data.

[0027] The charging interface module includes a charging interface, an electromagnetic locking mechanism, and a status detection sensor. The charging interface connects to the field-end positioning and charging unit to obtain power. The status detection sensor connects to both the charging interface and the electromagnetic locking mechanism, detecting the connection status of the charging interface and the locking status of the electromagnetic locking mechanism and sending these signals to the vehicle's main control module. The electromagnetic locking mechanism connects to the charging interface and also communicates with the vehicle's main control module. In response to the charging interface being connected and the electromagnetic locking mechanism being unlocked, the vehicle's main control module controls the electromagnetic locking mechanism to lock the charging interface. In this embodiment, the charging interface uses a standard DC fast charging interface and is equipped with an electromagnetic locking mechanism and a status detection sensor to provide feedback on the connection status and locking signal of the charging interface.

[0028] The field-end positioning and charging unit includes a UWB anchor array, a UWB base station gateway, an automatic charging mechanism, multiple charging stations, and a charging control module.

[0029] like Figure 2 As shown, the UWB anchor array consists of four UWB anchors deployed in a rectangular layout around the charging station, covering the charging station and a 5-meter radius around it. The UWB anchors are installed at a height of 2-3 meters and support multi-anchor collaborative operation to achieve blind-spot-free positioning. The association or data interaction between the UWB anchor array and other modules or units is described as follows: It is used to convert the pulse signals sent by the UWB positioning tags into positioning data and send them to the UWB base station gateway.

[0030] The UWB base station gateway is responsible for aggregating the positioning data collected from each UWB anchor point, preprocessing it, and then sending it to the scheduling and control unit. The association or data interaction between the UWB base station gateway and other modules or units is described as follows: It is used to forward positioning data to the scheduling and control unit and the automatic charging mechanism.

[0031] The automatic charging mechanism includes a driving unit, a base, a six-degree-of-freedom robotic arm, force feedback sensors, and a vision-assisted camera. The driving unit is located at the bottom of the base and is used to drive the automatic charging mechanism to move. The six-degree-of-freedom robotic arm is located on the base and connected to the scheduling control unit. The scheduling control unit is also connected to the force feedback sensors and the vision-assisted camera. There are six force feedback sensors, which are respectively located at the six wrists of the six-degree-of-freedom robotic arm. The vision-assisted camera is used to collect the position information of the charging gun and the charging interface and send it to the scheduling control unit. The force feedback sensors are used to collect the contact force at the wrist of the six-degree-of-freedom robotic arm and send it to the scheduling control unit. The scheduling control unit generates robotic arm control commands based on the position information of the charging gun and the charging interface and the contact force and sends them to the six-degree-of-freedom robotic arm. The six-degree-of-freedom robotic arm connects the charging gun at the charging station and the charging interface in the charging interface module according to the robotic arm control commands.

[0032] The charging control module features overcurrent, overvoltage, overtemperature, and short-circuit protection, and can monitor charging voltage, current, and battery temperature in real time to achieve intelligent charging control. Intelligent control is implemented during the charging process after the charging gun and charging interface are connected.

[0033] The dispatch control unit can be flexibly deployed in the cloud or on a local server at the site. As the core management and control unit of the system, it is responsible for location data fusion processing, docking and charging task scheduling, vehicle status monitoring, fault diagnosis, and data management. It supports simultaneous dispatching of multiple vehicles and can dynamically allocate charging resources based on vehicle remaining battery power, task priority, and charging station status. More specifically, the dispatch control unit is used to allocate available charging stations to the unmanned vehicles when it receives a charging request, plan the optimal path from the unmanned vehicle to the available charging station based on location data, and send the optimal path to the onboard main control module in the form of a dispatch command. It is also used to monitor the unmanned vehicle's driving path as it moves to the available charging station, and adjust the unmanned vehicle's driving path based on real-time location data when the unmanned vehicle deviates from the optimal path.

[0034] Example 3

[0035] This embodiment provides a method for parking and charging an unmanned vehicle, based on the unmanned vehicle parking and charging system provided in Embodiment 1, including the following steps: In response to the unmanned vehicle's battery level falling below a preset threshold, the onboard main control module sends a charging request to the dispatch control unit; The scheduling and control unit obtains the location data of the unmanned vehicle and the status information of each charging station. Based on the status information of each charging station, it allocates an available charging station to the unmanned vehicle. Based on the location data of the unmanned vehicle, it plans the optimal path from the unmanned vehicle to the available charging station and sends the optimal path to the on-board main control module in the form of a scheduling command. The onboard main control module controls the unmanned vehicle to drive along the optimal path to an available charging station according to the scheduling instructions until the unmanned vehicle completes parking. During this process, if the distance between the unmanned vehicle and the available charging station is greater than a first distance threshold, the onboard main control module uses an arrival time difference algorithm to control the unmanned vehicle to travel at a first speed. If the distance between the unmanned vehicle and the available charging station is greater than a second distance threshold but not greater than the first distance threshold, the onboard main control module uses a time-of-flight and arrival time difference fusion algorithm to control the unmanned vehicle to travel at a second speed. If the distance between the unmanned vehicle and the available charging station is not greater than the second distance threshold, the onboard main control module uses a time-of-flight algorithm to control the unmanned vehicle to travel at a third speed. Wherein, the first distance threshold is greater than the second distance threshold, the first speed is greater than the second speed, and the second speed is greater than the third speed. The automatic charging mechanism moves to the charging interface module based on the positioning data of the unmanned vehicle and connects the charging gun and the charging interface. The unmanned vehicle is charged under the control of the charging control module.

[0036] As can be seen from the above description of the technical solution, this embodiment is applicable to various unmanned vehicles such as unmanned shuttle vehicles, sorting vehicles, and inspection vehicles in low-speed scenarios such as closed parks, warehousing and logistics, campuses, and underground parking lots.

[0037] Example 4

[0038] like Figure 3 As shown, this embodiment provides a method for parking and charging an unmanned vehicle, which is implemented based on the unmanned vehicle parking and charging system provided in Embodiment 2, and includes the following steps: Step S1: UWB Precise Docking Guidance Process.

[0039] Step S1.1: In response to the unmanned vehicle's battery level falling below a preset threshold (20% in this embodiment, but other values ​​may be configured in other embodiments), the onboard main control module automatically sends a charging request to the scheduling control unit.

[0040] Step S1.2: The scheduling control unit queries the status of each charging station in the field positioning and charging unit, allocates the optimal idle charging station to the unmanned vehicle, plans the optimal path from the unmanned vehicle to the idle charging station based on the positioning data sent by the UWB base station gateway, and sends this optimal path to the vehicle main control module in the form of a scheduling command.

[0041] Step S1.3: The onboard main control module controls the unmanned vehicle to travel along the planned optimal path according to the information in the scheduling instructions. After entering the UWB positioning coverage area, that is, when the distance between the unmanned vehicle and the idle charging station does not exceed 50m, the UWB anchor array receives pulse signals from the UWB positioning tag, and then converts them into positioning data of the unmanned vehicle. This data is then forwarded to the scheduling control unit and the automatic charging mechanism through the UWB base station gateway, providing data support for the docking of the charging gun and the charging interface.

[0042] Step S1.4: In response to the distance between the unmanned vehicle and an available charging station exceeding a first distance threshold (5m in this embodiment), the onboard main control module uses a time-of-arrival (TOA) algorithm to control the unmanned vehicle to travel at a first speed (1m / s in this embodiment). This TOA algorithm guides the unmanned vehicle to quickly approach the available charging station. Step S1.4 corresponds to the unmanned vehicle's driving control at long distances.

[0043] Step S1.5: In response to the distance between the unmanned vehicle and the idle charging station being greater than the second distance threshold and not greater than the first distance threshold, the second distance threshold is set to 1m in this embodiment. The vehicle main control module uses the time-of-flight and time-of-arrival fusion algorithm to control the unmanned vehicle to travel at the second speed, which is set to 0.5m / s in this embodiment.

[0044] Furthermore, during the process of the vehicle-mounted main control module using the time-of-flight and time-of-arrival fusion algorithm to control the unmanned vehicle to travel at the second speed, the process also includes: the attitude detection module detecting the real-time attitude data of the unmanned vehicle and sending it to the vehicle-mounted main control module; the vehicle-mounted main control module adjusting the attitude of the unmanned vehicle according to the scheduling instructions and the real-time attitude data, that is, starting the initial attitude adjustment.

[0045] Step S1.5 corresponds to the driving control and initial attitude adjustment of the unmanned vehicle at medium distance.

[0046] Step S1.6: In response to the fact that the distance between the unmanned vehicle and the idle charging station is not greater than the second distance threshold, the on-board main control module uses the time-of-flight algorithm to control the unmanned vehicle to travel at the third speed, which is 0.2m / s in this embodiment.

[0047] Furthermore, during the process of the vehicle-mounted main control module using the time-of-flight algorithm to control the unmanned vehicle to travel at the third speed, the following steps are also included: the attitude detection module detects the real-time attitude data of the unmanned vehicle and sends it to the vehicle-mounted main control module. Based on the scheduling instructions and real-time attitude data, the vehicle-mounted main control module combines Kalman filtering and PID control to make secondary adjustments to the attitude of the unmanned vehicle, that is, to begin fine attitude adjustment. The adjustment time for the secondary adjustment does not exceed 10 seconds.

[0048] Step S1.6 corresponds to the driving control and fine attitude adjustment of the unmanned vehicle at close range.

[0049] Step S1.7: When the docking alignment error between the unmanned vehicle and the endpoint of the optimal path does not exceed the third distance threshold, and the vehicle's posture deviation does not exceed the preset angle threshold, the unmanned vehicle completes docking, and the onboard main control module controls the unmanned vehicle's parking brake. In this embodiment, the third distance threshold is set to 4cm, and the preset angle threshold is set to 2°.

[0050] Vehicle attitude deviations include vehicle yaw angle deviation, vehicle pitch angle deviation, and vehicle roll angle deviation. The vehicle yaw angle deviation is the absolute value of the difference between the real-time vehicle yaw angle and the preset vehicle yaw angle. The vehicle pitch angle deviation is the absolute value of the difference between the real-time vehicle pitch angle and the preset vehicle pitch angle. The vehicle roll angle deviation is the absolute value of the difference between the real-time vehicle roll angle and the preset vehicle roll angle.

[0051] Step S2, UWB Collaborative Automatic Charging Process.

[0052] Step S2.1: After docking is completed, the on-board main control module sends a docking completion signal to the dispatch control unit.

[0053] Step S2.2: The scheduling and control unit triggers a charging docking command. Under the guidance of UWB positioning, the automatic charging mechanism moves to the vicinity of the charging interface and performs a rough docking with the charging gun and the charging interface through a six-degree-of-freedom robotic arm.

[0054] Step S2.3: The visual auxiliary camera collects the position information of the charging gun and charging interface and sends it to the scheduling control unit. The force feedback sensor collects the contact force at the wrist of the six-degree-of-freedom robotic arm and sends it to the scheduling control unit. The scheduling control unit generates robotic arm control commands based on the position information of the charging gun and charging interface and the contact force, and sends them to the six-degree-of-freedom robotic arm. The six-degree-of-freedom robotic arm performs a secondary docking of the charging gun and charging interface according to the robotic arm control commands, and maintains the contact force not exceeding the contact force threshold during the secondary docking process, until the center position deviation of the charging gun and charging interface is not greater than the fourth distance threshold, completing the fine docking of the charging gun and charging interface. The docking accuracy does not exceed 3cm, and the contact force threshold is set to 5N during the docking process to avoid damaging the charging interface.

[0055] Step S2.4: After docking is completed, the electromagnetic locking mechanism in the charging interface module automatically locks, and the charging control module performs insulation detection and communication handshake.

[0056] Step S2.5: After a successful handshake, the charging process is initiated, and the charging control module dynamically adjusts the charging power according to the battery status.

[0057] Step S2.6: During the charging process, the system monitors the charging status and vehicle status in real time. If any abnormality occurs, the system will immediately cut off the power and issue an alarm.

[0058] Step S2.7: When the battery charge reaches 95% or a departure command is received, charging will automatically stop and the electromagnetic locking mechanism in the electrical interface module will be unlocked.

[0059] Step S2.8: The automatic charging mechanism retracts the charging gun, the dispatch control unit sends a departure command to the vehicle, and the unmanned vehicle autonomously drives away from the charging station, completing the entire charging process.

[0060] This embodiment also includes the following exception handling mechanism: When the docking alignment error exceeds 8cm, the attitude adjustment retry process is automatically triggered. After three failed retries, a fault alarm is issued. When charging docking fails, the charging gun will automatically retract and re-dock. After two failed attempts, a fault alarm will be issued. If any abnormalities such as overcurrent, overvoltage, or overtemperature occur during the charging process, immediately disconnect the charging power, lock the charging interface, and notify the maintenance personnel. When critical system equipment, such as UWB anchor points, automatic charging mechanisms, and charging modules, malfunctions, the corresponding charging station is automatically marked as unavailable, and a fault work order is generated.

[0061] Based on the above embodiments, the present invention has the following beneficial effects: 1. High positioning accuracy: Utilizing UWB technology combined with a fusion algorithm, centimeter-level positioning is achieved, with a docking alignment error of ≤4cm and a charging docking accuracy of ≤4cm. This completely solves the problem of insufficient positioning accuracy in existing technologies, eliminating the need for manual docking assistance and improving the success rate of charging docking.

[0062] 2. High charging efficiency: It realizes full automation of parking, docking, charging and departure, with attitude adjustment time ≤10 seconds, which greatly shortens the charging preparation time, improves the operational continuity of unmanned vehicles, and meets the needs of high-frequency operation.

[0063] 3. Strong scene adaptability: Optimized UWB positioning algorithm and hardware deployment, strong anti-interference ability, adaptable to complex scenarios such as indoor, underground, and warehouse, supports simultaneous charging of multiple vehicles, adaptability to different types of unmanned vehicles, strong versatility, and can be widely used in various low-speed unmanned vehicle scenarios.

[0064] 4. Low operation and maintenance costs: The entire process requires no manual intervention, reducing manual operation and maintenance costs. At the same time, the system has a complete fault early warning mechanism, which can detect and handle equipment failures in a timely manner, reduce equipment failure rate, extend equipment life and further reduce operation and maintenance costs.

[0065] 5. Simple structure and easy deployment: The hardware is highly reusable. The UWB positioning system is compatible with the existing positioning system of the unmanned vehicle. The deployment of UWB anchor points at the field is convenient, without the need for large-scale site modifications. The deployment cost is low, making it easy to promote and apply on a large scale.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A parking and charging system for unmanned vehicles based on UWB technology, characterized in that, This includes an onboard execution unit, a field-end positioning and charging unit, and a scheduling and control unit; The vehicle-mounted execution unit includes a UWB positioning tag, a vehicle-mounted main control module, and a charging interface module. The charging interface module is used to connect the field-end positioning and charging unit to obtain power. The UWB positioning tag is installed on the unmanned vehicle near the charging interface module and is used to send pulse signals to the UWB anchor array. The vehicle-mounted main control module is used to send charging requests to the scheduling control unit and also to receive scheduling instructions and control the unmanned vehicle to drive accordingly. The field-end positioning and charging unit includes a UWB anchor array, a UWB base station gateway, an automatic charging mechanism, multiple charging stations, and a charging control module. The UWB anchor array is used to convert pulse signals into positioning data and send them to the UWB base station gateway. The UWB base station gateway is used to forward the positioning data to the scheduling control unit and the automatic charging mechanism. The automatic charging mechanism is used to move to the location of the charging interface module based on the positioning data, and also to connect the charging gun on the charging station to the charging interface in the charging interface module. The charging control module is used to realize intelligent control during the charging process. The scheduling and control unit is used to allocate an available charging station to the unmanned vehicle when it receives a charging request. It plans the optimal path from the unmanned vehicle to the available charging station based on the positioning data and sends the optimal path to the on-board main control module in the form of a scheduling command.

2. The unmanned vehicle parking and charging system based on UWB technology according to claim 1, characterized in that, The charging interface module includes a charging interface, an electromagnetic locking mechanism, and a status detection sensor. The charging interface is used to connect the field-end positioning and charging unit to obtain electrical energy; The status detection sensor is connected to the charging interface and the electromagnetic locking mechanism respectively, and is used to detect the connection status of the charging interface and the locking status of the electromagnetic locking mechanism and send them to the vehicle main control module. The electromagnetic locking mechanism is connected to the charging interface and also communicates with the vehicle main control module. In response to the charging interface being connected and the electromagnetic locking mechanism being unlocked, the vehicle main control module controls the electromagnetic locking mechanism to lock the charging interface.

3. The unmanned vehicle parking and charging system based on UWB technology according to claim 1, characterized in that, The vehicle-mounted execution unit also includes an attitude detection module, which is used to detect the real-time attitude data of the unmanned vehicle and send it to the vehicle-mounted main control module. The real-time attitude data includes the real-time vehicle yaw angle, the real-time vehicle pitch angle and the real-time vehicle roll angle. The onboard main control module is also used to adjust the attitude of the unmanned vehicle according to scheduling instructions and real-time attitude data.

4. The unmanned vehicle parking and charging system based on UWB technology according to claim 1, characterized in that, The scheduling and control unit is also used to monitor the driving path of the unmanned vehicle as it drives toward an empty charging station. When the unmanned vehicle deviates from the optimal path, the driving path of the unmanned vehicle is adjusted based on real-time positioning data.

5. The unmanned vehicle parking and charging system based on UWB technology according to claim 1, characterized in that, The automatic charging mechanism includes a driving unit, a base, a six-degree-of-freedom robotic arm, a force feedback sensor, and a visual auxiliary camera. The driving unit is located at the bottom of the base and is used to drive the automatic charging mechanism to move; A six-degree-of-freedom robotic arm is mounted on the base and connected to a scheduling and control unit. The scheduling and control unit is also connected to force feedback sensors and visual auxiliary cameras. There are six force feedback sensors, which are respectively installed at the six wrists of the six-degree-of-freedom robotic arm. The visual auxiliary cameras are used to collect the position information of the charging gun and the charging interface and send it to the scheduling and control unit. The force feedback sensors are used to collect the contact force at the wrists of the six-degree-of-freedom robotic arm and send it to the scheduling and control unit. The scheduling and control unit generates robotic arm control commands based on the position information of the charging gun and the charging interface and the contact force and sends them to the six-degree-of-freedom robotic arm. The six-degree-of-freedom robotic arm docks the charging gun and the charging interface according to the robotic arm control commands.

6. A method for parking and charging an unmanned vehicle based on the unmanned vehicle parking and charging system according to any one of claims 1 to 5, characterized in that, include: In response to the unmanned vehicle's battery level falling below a preset threshold, the onboard main control module sends a charging request to the dispatch control unit. The scheduling and control unit obtains the location data of the unmanned vehicle and the status information of each charging station. Based on the status information of each charging station, it allocates an available charging station to the unmanned vehicle. Based on the location data of the unmanned vehicle, it plans the optimal path from the unmanned vehicle to the available charging station and sends the optimal path to the on-board main control module in the form of a scheduling command. The onboard main control module controls the unmanned vehicle to drive along the optimal path to an available charging station according to the scheduling instructions until the unmanned vehicle completes parking. During this process, if the distance between the unmanned vehicle and the available charging station is greater than a first distance threshold, the onboard main control module uses an arrival time difference algorithm to control the unmanned vehicle to travel at a first speed. If the distance between the unmanned vehicle and the available charging station is greater than a second distance threshold but not greater than the first distance threshold, the onboard main control module uses a time-of-flight and arrival time difference fusion algorithm to control the unmanned vehicle to travel at a second speed. If the distance between the unmanned vehicle and the available charging station is not greater than the second distance threshold, the onboard main control module uses a time-of-flight algorithm to control the unmanned vehicle to travel at a third speed. Wherein, the first distance threshold is greater than the second distance threshold, the first speed is greater than the second speed, and the second speed is greater than the third speed. The automatic charging mechanism moves to the charging interface module based on the positioning data of the unmanned vehicle and connects the charging gun and the charging interface. The unmanned vehicle is charged under the control of the charging control module.

7. The method for parking and charging an unmanned vehicle according to claim 6, characterized in that, When the docking alignment error between the unmanned vehicle and the endpoint of the optimal path does not exceed the third distance threshold, and the vehicle body posture deviation does not exceed the preset angle threshold, the unmanned vehicle completes the docking, and the on-board main control module controls the parking brake of the unmanned vehicle. The vehicle attitude deviation includes vehicle yaw angle deviation, vehicle pitch angle deviation, and vehicle roll angle deviation. The vehicle yaw angle deviation is the absolute value of the difference between the real-time vehicle yaw angle and the preset vehicle yaw angle. The vehicle pitch angle deviation is the absolute value of the difference between the real-time vehicle pitch angle and the preset vehicle pitch angle. The vehicle roll angle deviation is the absolute value of the difference between the real-time vehicle roll angle and the preset vehicle roll angle.

8. The method for parking and charging an unmanned vehicle according to claim 6, characterized in that, During the process of the vehicle-mounted main control module using the time-of-flight and time-of-arrival difference fusion algorithm to control the unmanned vehicle to travel at the second speed, the system also includes: an attitude detection module detecting the real-time attitude data of the unmanned vehicle and sending it to the vehicle-mounted main control module; and the vehicle-mounted main control module adjusting the attitude of the unmanned vehicle once according to the scheduling instructions and the real-time attitude data. During the process of the vehicle-mounted main control module using the time-of-flight algorithm to control the unmanned vehicle to travel at the third speed, the system also includes: an attitude detection module that detects the real-time attitude data of the unmanned vehicle and sends it to the vehicle-mounted main control module; and the vehicle-mounted main control module, based on the scheduling instructions and the real-time attitude data, combined with Kalman filtering and PID control, making secondary adjustments to the attitude of the unmanned vehicle.

9. The method for parking and charging an unmanned vehicle according to claim 6, characterized in that, The automatic charging mechanism moves to the charging interface module location based on the unmanned vehicle's positioning data, and docks the charging gun and charging interface, including: The automatic charging mechanism moves to the charging interface module based on the positioning data of the unmanned vehicle, and uses a six-degree-of-freedom robotic arm to dock the charging gun and the charging interface once. A visual auxiliary camera collects the position information of the charging gun and charging interface and sends it to the scheduling control unit. A force feedback sensor collects the contact force at the wrist of the six-degree-of-freedom robotic arm and sends it to the scheduling control unit. The scheduling control unit generates robotic arm control commands based on the position information of the charging gun and charging interface and the contact force and sends them to the six-degree-of-freedom robotic arm. The six-degree-of-freedom robotic arm performs a secondary docking of the charging gun and charging interface according to the robotic arm control commands, and maintains the contact force not exceeding the contact force threshold during the secondary docking process, until the center position deviation of the charging gun and charging interface is not greater than the fourth distance threshold, thus completing the docking of the charging gun and charging interface.

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