Method and system for unmanned paving coordination of multiple machines based on CAN bus

Abstract

Embodiments of the present application disclose a CAN bus-based multi-machine cooperative unmanned paving control method and system and a storage medium. The method comprises: when a first component has a first message of a first priority to send and it is detected that a CAN bus is occupied by a second component, determining whether a second message sent by the second component is of a second priority; when the second message is of the second priority, preempting the CAN and sending the first message using the CAN bus; a head of a first message comprises a first sequence; the first sequence is used to instruct the second component to pause sending of the second message; a tail of a last first message carries a second sequence; when the second message is of the first priority or the first component has a third message of the second priority to send and it is detected that the CAN bus is occupied by the second component, waiting for the second component to finish sending the second message and then contending for the CAN bus based on the second priority; and sending a message of the first priority to a second paving device wirelessly.

Description

Technical Field

[0001] This invention relates to the field of construction technology, and in particular to a multi-machine collaborative unmanned paving control method and system based on CAN bus. Background Technology

[0002] Paving equipment is a core piece of construction equipment in road construction. It is mainly used to evenly spread paving materials such as asphalt and water-stabilized layers on the road base to form a paving layer that meets design requirements. Its operational accuracy, efficiency, and collaborative performance directly affect the quality and progress of road construction. In existing multi-machine collaborative unmanned paving scenarios, paving equipment needs to complete operations through the collaboration of multiple components. The reliability of communication and the rationality of priority control between these components are crucial to the safety and operational quality of unmanned paving. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a multi-machine cooperative unmanned paving control method and system based on CAN bus. The technical solution of the present invention is implemented as follows: The first aspect provides a multi-machine collaborative unmanned paving control method based on a Controller Area Network (CAN) bus, executed by a first paving device. The first paving device includes multiple functional components connected via a CAN bus. These functional components include a first component, a second component, and a third component. Specifically, each functional component includes sensors, actuators, a wireless communication module, and a controller. The method includes: setting multiple priority levels for different types of messages based on the paving task currently being performed by the paving device; these priority levels include a first priority level and a second priority level; the first priority level is related to safety and a first indicator of the paving task; the second priority level is related to paving operation control; when the first component sends a first message of the first priority level and detects that the CAN bus is occupied by the second component, determining whether the second message sent by the second component is of the second priority level; when the second message is of the second priority level, preempting the CAN bus and using the CAN bus to send the first message; the first message... The header includes a first sequence; the first sequence is used to instruct the second component to pause the transmission of the second message, and is used by each functional component to buffer the received second message in the first channel; the first message is buffered by each functional component in the second channel; the last first message carries a second sequence; the second sequence is used to instruct the second component to resume the transmission of the second message within a first duration, and the third component not to participate in the CAN bus occupation contention and resume listening to the first message within the second duration; the first duration is less than the second duration; when the second message is of the first priority, the CAN bus is competed for based on the second priority after the second component finishes sending the second message; when the first component has a third message of the second priority to send and listens to the CAN bus being occupied by the second component, the CAN bus is competed for based on the second priority after the second component finishes sending the second message; after the wireless communication module listens to the first priority message on the CAN bus, it wirelessly sends the first priority message to the second paving device.

[0004] The second aspect provides a multi-machine collaborative unmanned paving control system based on a CAN bus of a controller area network (CAN), executed by a first paving device. The first paving device includes multiple functional components connected via a CAN bus. These functional components include a first component, a second component, and a third component. Specifically, each functional component includes sensors, actuators, a wireless communication module, and a controller. The system includes: a setting module, used to set multiple priorities for different types of messages based on the paving task currently being performed by the paving device; these priorities include a first priority and a second priority; the first priority is related to safety and a first indicator of the paving task; the second priority is related to paving operation control; a determining module, used to determine whether a second message sent by the second component is of the second priority when the first component sends a first message of the first priority and the CAN bus is detected to be occupied by the second component; and a sending module, used to preempt the CAN bus and send the first message using the CAN bus when the second message is of the second priority. The header of a message includes a first sequence; the first sequence is used to instruct the second component to pause the transmission of the second message, and is also used by each functional component to buffer the received second message in the first channel; the first message is buffered by each functional component in the second channel; the tail of the last first message carries a second sequence; the second sequence is used to instruct the second component to resume the transmission of the second message within a first duration, and the third component not to participate in the CAN bus occupation contention and to resume listening to the first message within the second duration; the first duration is less than the second duration; a waiting module is used to wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority when the second message is of the first priority; when the first component has a third message of the second priority to send and listens that the CAN bus is occupied by the second component, it waits for the second component to finish sending the second message and then competes for the CAN bus based on the second priority; a sending module is also used to wirelessly send the first priority message to the second paving device after the wireless communication module listens for the first priority message on the CAN bus.

[0005] The third aspect provides a computer-readable storage medium storing computer-executable instructions; after being executed by a processor, the computer-executable instructions are able to implement the method provided by any of the technical solutions of the first aspect.

[0006] The technical solution provided in this disclosure has the following effects: By setting priority categories for the first type (related to safety and the first indicator of paving tasks) and the second type (related to paving operation control) based on the paving task, the priority difference between the two types of messages is clarified, and priority distinction of message transmission is achieved. This avoids irrelevant messages from interfering with the transmission of safety and core operation-related messages, ensuring the safety of unmanned paving operations and the stability of core operation indicators. It also solves the problems of priority confusion and easy interference of core messages in traditional multi-component communication.

[0007] To address the bus occupancy scenario when the first component sends a first-priority message, the priority of the second component's message is determined to allow the second-priority message to avoid the first-priority message. Simultaneously, the instructions of the first and second sequences enable the second component to pause, resume interrupted transmission, and the third component to monitor and control the transmission. Furthermore, the dual-buffering design of the first and second channels ensures that messages are not lost or duplicated, guaranteeing the continuity and reliability of CAN bus communication and avoiding problems such as message transmission failure and instruction delay caused by bus conflicts.

[0008] By listening to the first-priority messages on the CAN bus through the wireless communication module and wirelessly forwarding them to the second paving equipment, the synchronous transmission of core messages (first-priority messages) among multiple paving equipment is realized. This ensures the timely synchronization of safety and core operation-related messages among the equipment during unmanned paving with multiple machines working together, improves the coordination of multi-machine collaboration, and solves the problems of untimely message transmission and poor coordination in traditional multi-machine collaboration.

[0009] Through the synergistic effect of the above features, orderly communication and reasonable priority control among the functional components of the first paving equipment are achieved, as well as reliable synchronization of core messages between multiple machines. This effectively improves the automation level, communication reliability, and multi-machine collaboration efficiency of unmanned paving operations, while reducing risks such as bus conflicts and message loss, thus providing strong protection for the safety and stability of unmanned paving operations. Attached Figure Description

[0010] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A schematic diagram of a multi-machine collaborative unmanned paving control system based on CAN bus provided for an embodiment of the present invention; Figure 2 A flowchart illustrating a multi-machine collaborative unmanned paving control method based on CAN bus provided in an embodiment of the present invention; Figure 3 A schematic diagram of a multi-machine collaborative unmanned paving control system based on CAN bus provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the electronic device used in a multi-machine collaborative unmanned paving control system based on a CAN bus, as provided in an embodiment of the present invention. Detailed Implementation

[0011] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0012] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0013] This application proposes a multi-machine collaborative unmanned paving control method based on a Controller Area Network (CAN) bus. By deploying multiple CAN bus-connected functional components within the first paving device and setting multiple priorities for different message types according to the paving task, fine-grained management of CAN bus communication is achieved. When a high-priority message needs to be sent, the system can intelligently determine bus occupancy and adopt different processing strategies based on the priority of the occupied message, ensuring the real-time transmission of critical information (such as safety and messages related to the primary indicators of the paving task). Simultaneously, high-priority messages are forwarded to other paving devices via a wireless communication module, effectively improving the real-time performance, reliability, and intelligence level of multi-machine collaborative operations, thereby overcoming problems such as communication delays, low collaborative efficiency, and unstable paving quality in traditional paving operations.

[0014] The first paving equipment can be any paving equipment; the main difference is that it is used to distinguish the paving equipment from other paving equipment in a multi-machine collaborative operation. For example, paving equipment is an automated construction machine that integrates walking, paving, and leveling functions. It mainly consists of three parts: a walking mechanism (including tracks / tires, drive motors, and transmission systems, which detect movement speed and trajectory through speed / position sensors), a paving mechanism (including hoppers, scraper conveyors, auger distributors, and screeds, which use thickness / temperature / speed sensors to monitor the paving layer thickness, material temperature, and material distribution uniformity in real time), and a leveling mechanism (such as vibrating beams and screed vibrators, which monitor vibration parameters through acceleration sensors and use visual sensors to assist in detecting surface flatness). It is equipped with environmental sensors (ambient temperature and humidity, wind speed), equipment status sensors (engine speed, hydraulic pressure, etc.), and an integrated controller (PLC / industrial computer, collaborative control software, and wireless communication module). The various functional components are connected through a CAN bus. Based on multi-priority message management (distinguishing between safety / operation control message types), AI intelligent control (real-time analysis of paving material, environmental, and equipment status data, and dynamic adjustment of paving parameters), and positioning calibration (satellite + local wireless positioning cross-verification), it achieves precise paving, multi-machine collaboration, and safe operation.

[0015] like Figure 2 As shown, the method provided in this embodiment includes: S1110: Based on the paving task currently being performed by the paving equipment, set multiple priorities for different types of messages; the multiple priorities include a first priority and a second priority; the first priority is related to safety and the first indicator of the paving task; the second priority is related to paving operation control. S1120: When the first component sends a first message of the first priority and detects that the CAN bus is occupied by the second component, determine whether the second message sent by the second component is of the second priority. S1130: When the second message is of the second priority, the CAN bus is preempted to send the first message; the header of the first message includes a first sequence; the first sequence is used to instruct the second component to pause the transmission of the second message, and is used to buffer the first message received by any functional component receiving the first message in the first channel; the first message is buffered by each functional component in the second channel; the tail of the last message carries a second sequence; the second sequence is used to instruct the second component to resume the transmission of the second message within a first duration, and the third component does not participate in the CAN bus occupation contention and resumes listening to the first message within the second duration; the first duration is less than the second duration; S1140: When the second message is of the first priority, wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority. S1150: When the first component sends a third message of the second priority and detects that the CAN bus is occupied by the second component, wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority. S1160: After listening to a first-priority message on the CAN bus, it wirelessly sends the first-priority message to the second paving device.

[0016] CAN bus, or Controller Area Network bus, is a serial communication bus with high reliability, real-time performance, and error detection capabilities. It allows multiple electronic control units (ECUs) to communicate without a controller, thereby achieving distributed control. In this embodiment, the CAN bus is used to connect various functional components within the paving equipment to achieve efficient data exchange and command transmission within the equipment.

[0017] Paving operations are generally an uninterrupted, continuous physical process, demanding near-zero tolerance for real-time safety response. The inherent flaw of traditional CAN bus non-preemptive mechanisms lies in the fact that even the highest-priority emergency messages (such as personnel intrusion alarms) must wait for any lower-priority message on the current bus (such as periodic equipment temperature reports) to be fully transmitted. This can result in delays of tens of milliseconds, which, for a high-speed paver, is sufficient to cause a serious safety incident. Existing technologies, through optimizing message length or priority division, cannot fundamentally solve this deterministic delay problem in the worst-case scenario. Therefore, this application provides a preemptive mechanism for the CAN bus.

[0018] In view of this, the preemption mechanism of the CAN bus includes an application layer preemption mechanism and / or a hardware layer preemption mechanism.

[0019] When executing the application layer preemption mechanism, the CAN bus preemption is specifically as follows: The application layer of the first component sends a first application layer message to the CAN controller of the first component; wherein the first application layer message contains the first message. The CAN controller of the first component encapsulates the first application layer message into a first CAN frame and transmits it on the CAN bus; After receiving the first CAN frame, the CAN controller of the second component decapsulates the first CAN frame into a second application layer message and sends the second application layer message to the application layer of the second component. The application layer of the second component triggers an interrupt based on the second application layer message to pause the transmission of the second message and save the context information; the context information is used to resume the transmission of the second message; After receiving the first CAN frame, the CAN controller of the third component decapsulates the first CAN frame into a third application layer message and sends it to the application layer of the third component. The application layer of the third component marks the CAN bus as a preset time period based on the third application layer message and the second duration, so as not to participate in CAN bus contention within the preset time period.

[0020] When the hardware layer preemption mechanism is executed, the CAN bus preemption is specifically as follows: The CAN controller of the first component transmits a second CAN frame via the CAN bus during the inter-frame interval of the CAN bus; wherein the second CAN frame is generated based on the first message of the first component. After the CAN controller of the second component receives the second CAN frame, it stops the transmission of the second priority message of the current second component and caches the breakpoint information in the hardware buffer. The breakpoint information is used to resume the transmission of the second priority message. After receiving the second CAN frame, the CAN FD controller of the third component shields the CAN bus contention and maintains a listening state for a preset period based on the second duration.

[0021] In some embodiments, the context information refers to application layer state data stored at the application layer for restoring the sending of the second message, including but not limited to sending progress, message identifier, and queue pointer.

[0022] Breakpoint information refers to hardware state data cached by the CAN FD controller for resuming the transmission of second-priority messages, including but not limited to the transmission breakpoint location, buffer pointer, and frame identifier.

[0023] In some embodiments, an application-layer preemption mechanism is introduced while fully preserving the standard protocols of the CAN bus physical layer and data link layer (i.e., without changing the hardware foundation). By designing a first sequence and a second sequence at the protocol layer, controlled interruption and recovery of low-priority transmissions are achieved. A predictable and recoverable controlled interruption process is implemented through sequence instructions: after the first sequence instruction of the first message is received by the component occupying the bus, it can orderly pause its current task and buffer its context; the second sequence of the last message ensures that the interrupted task can resume transmission after a specified time, and other components also pause competition according to the instructions, thereby quickly restoring the system to normal operation after the preemption ends. This design transforms the worst-case time of a secure response from an unpredictable variable into a measurable constant at the microsecond level, achieving a qualitative leap in the system's real-time response capability from statistical reliability to deterministic reliability.

[0024] For example, the preemption mechanism described in this application can be implemented in the application layer protocol stack of a standard CAN controller. Specifically, when the first component needs to send a first message of the first priority and detects that the CAN bus is occupied by the second component, the microcontroller (MCU) of the first component confirms the bus busy state by reading the status register of the CAN controller and sends a high-priority control message to the second component. The ID field of this control message is set to the first priority identifier reserved by the system (such as 0x000), and the data field contains the first sequence (0xAA55) and the address code of the second component. After receiving the control message, the application layer protocol stack of the second component immediately triggers the interrupt service routine, suspends the assembly of the data field of the current second message, writes the assembled second message data segment (including the filled data field bytes and the remaining unsent data) into the local first channel buffer (this buffer is a circular buffer in the internal RAM of the second component's MCU with a capacity of 256 bytes, which is sufficient to store the complete data field of a standard CAN frame), and at the same time sends a command to the CAN controller to abandon the current transmission (set the AT bit of the CMR register) to release the CAN bus. After confirming the bus is idle, the first component begins sending the first message. The arbitration field ID of this message corresponds to the first priority level. The first message header includes a first sequence to inform other components that this is a preemption message. The last message appends a second sequence (0x55AA) and a first duration parameter (e.g., 50 milliseconds). Upon receiving the first message, other functional components (including the third component) parse the first sequence identifier in the data field, transfer received but unprocessed message data to the second channel buffer (this buffer is an independent buffer defined in the internal RAM of each component's MCU, physically isolated from the first channel to avoid data confusion), and suspend sending any messages to the CAN bus. After the first message is sent, the application layer protocol stack of the second component detects the bus is idle, reads the breakpoint data stored in the first channel buffer, and resumes the assembly and transmission of the second message from the breakpoint. This recovery process is completed within the first duration (50 milliseconds). The third component continuously listens to the CAN bus for the second duration (100 milliseconds) without participating in bus contention. After the second duration expires, it resumes normal message listening and transmission functions. The above-mentioned application-layer preemption mechanism is implemented entirely based on the standard CAN 2.0B protocol. It does not require modification of the CAN controller's hardware logic. The preemption effect is achieved through software-level protocol design, while the dual-channel buffer mechanism ensures the integrity and recoverability of interrupted messages.

[0025] In some embodiments, the hardware-layer preemption mechanism can be based on a CAN Flexible Data-rate (FD) controller that supports hardware preemption, supporting transmit pause and frame interleaving functions. Specifically, the CAN FD controller is internally configured with a transmit priority queue (TPQ) and a preemptive transmit buffer (PTB). The first message of the first component is written to the PTB and marked with a preemptive attribute after generation (by setting the PREEMPT bit of the PTB control register), while the second message of the second component is stored in the TPQ. When the CAN bus is occupied by the second component and is in the inter-frame space (IFS) or the data field transmission phase of the current frame, the CAN FD controller of the first component detects the preemption request in the PTB at the hardware level. If the priority of the current transmission frame is lower than that of the frame in the PTB (by comparing the arbitration field ID), the controller immediately inserts an error frame or a specific protocol control frame after the current bit cycle ends, forcibly terminating the second message transmission of the second component. The transmitted data segment of the second message is automatically buffered by the CAN FD controller of the second component in the internal Transmit History List (THL) or the first channel specified by the application layer (external SRAM, written via the controller's data interface DMA). After the bus is idle, the CAN FD controller of the first component loads the first message from the PTB. The arbitration field of this message contains a first priority identifier, the data field header embeds a first sequence (automatically generated by the controller hardware or pre-written by software), and the data field tail embeds a second sequence and a first duration parameter. After the first message transmission is completed, the CAN FD controller of the second component triggers a transmit interrupt. The application layer reads the breakpoint information from the THL in the interrupt service routine and resumes the transmission of the second message from the breakpoint within the first duration (implemented by a hardware timer or software delay, 50 milliseconds). This recovery process is automatically managed by the controller hardware for retransmission counting and bit stuffing. After detecting a preemption event in the bus status register, the CAN FD controller of the third component automatically enters listen mode (by setting the LPM bit in the mode register), disables its own transmit function, and automatically exits listen mode after the second duration (100 milliseconds, controlled by the controller's internal watchdog timer or system tick timer) and resumes the transmit function.The aforementioned hardware preemption implementation relies on the specific function register configuration of the CAN FD controller, including PTB enable, preemption priority threshold setting, THL depth configuration (supporting the storage of breakpoint data for up to 8 interrupt frames), and timer parameter register writing. These configurations are completed by the controller firmware during the power-on initialization phase of the paving equipment, ensuring the determinism and real-time performance of the preemption mechanism at the hardware level. Its response latency can be controlled at the microsecond level (typically less than 10 microseconds), which is far superior to the millisecond-level latency of application-layer simulated preemption.

[0026] In this embodiment, the data field is used to load communication control information such as the first sequence, the second sequence, priority identifier, duration parameters, and message content. When preemption occurs, the transmission of the data field can be interrupted by the CAN FD controller and / or the application layer, and breakpoint resumption is achieved through dual-channel buffering. The message header and / or tail sequences are both written into the data field to implement preemption, pause, resume, and buffering control. The data field is used to carry pause instructions, buffering instructions, and resume instructions during the preemption process.

[0027] In some embodiments, the CAN bus can support application-layer preemption alone, hardware-layer preemption alone (preemption based on the CAN FD controller), or both application-layer and application-layer preemption simultaneously. When both hardware and application-layer preemption are supported, application-layer preemption is given priority. If application-layer preemption does not meet real-time requirements, it automatically switches to hardware-layer preemption. The application-layer preemption is implemented through a first sequence and a second sequence, while the hardware-layer preemption is implemented by the CAN FD controller terminating the current frame transmission.

[0028] When a first-priority message needs to be sent, application-layer preemption is performed first; if application-layer preemption fails or bus delay exceeds the threshold, hardware-layer preemption is initiated to forcibly interrupt the transmission of second-priority messages.

[0029] The application layer preemption mechanism and hardware layer preemption mechanism of this disclosure are fully compatible with existing CAN 2.0 and CAN FD standard protocols, comply with ISO 11898 specifications, do not modify the physical layer and data link layer, can be directly adapted to existing standard CAN components of paving equipment, and can achieve deterministic real-time transmission of high-priority messages without replacing hardware.

[0030] The application layer preemption mechanism is included in the standard CAN protocol framework. It uses the message data field to carry the first / second sequence and cooperates with dual-channel buffering to realize the suspension and interruption resumption of low-priority messages without interrupting the frame being transmitted or generating error frames.

[0031] The hardware-layer preemption mechanism is based on the inter-frame interval and standard register control of the standard CAN FD controller. It intervenes in scheduling only during the inter-frame idle phase, does not forcibly terminate messages in transmission, and does not violate standard bus arbitration rules. The application-layer preemption does not rely on dedicated hardware at all, has the strongest compatibility, low implementation cost, no abnormal frames on the bus, high stability, and is suitable for scenarios with strong vibration of pavers and mixed use of multiple devices. The hardware-layer preemption has a faster response speed and higher latency determinism. It does not require software to participate in complex logic and can meet the microsecond-level real-time requirements of safety messages in unmanned paving. The progressive execution order of first enabling application-layer preemption and automatically upgrading to hardware-layer preemption when real-time requirements are not met can obtain the highest level of real-time performance on demand while prioritizing compatibility and stability. It avoids bus fluctuations caused by frequent hardware preemption in routine operations and can quickly trigger hard real-time protection in emergency safety scenarios, achieving the optimal balance between compatibility, stability, and real-time performance, which is more in line with the complex operation requirements of multi-machine collaborative unmanned paving.

[0032] A functional component refers to a hardware or software unit that constitutes a paving device and performs a specific function. In this embodiment, the functional components include sensors, actuators, a wireless communication module, and a controller. Sensors are responsible for collecting various data during the paving process; actuators are responsible for performing specific mechanical actions according to control commands, such as adjusting the paving slab height and controlling the travel speed; the wireless communication module is responsible for wireless data transmission with other devices; and the controller, as the core processing unit, is responsible for receiving and processing data and generating control commands. The first, second, and third components are exemplary classifications of this functional component, used to describe the interactive behavior of different components in CAN bus communication.

[0033] In this embodiment, the preemption mechanism can be categorized into a gradual preemption mechanism and an immediate preemption mechanism based on its preemption rate. For example, a gradual preemption mechanism sends a warning frame carrying a delay duration to the second component, allowing it to actively release the CAN bus after completing the transmission of a specified data segment within a limited time. An immediate preemption mechanism, on the other hand, immediately suspends the second component's second message transmission and occupies the CAN bus by immediately executing the hardware-level preemption mechanism or the application-level preemption mechanism.

[0034] In some embodiments, the gradual preemption mechanism is enabled under normal operating conditions, and switched to the immediate preemption mechanism under critical operating conditions. The critical operating condition is an operating condition in which an event related to personnel safety and specified equipment safety occurs when the remaining duration of the paving time window generated based on the paving material characteristics and paving requirements is less than a critical threshold; the normal operating condition is an operating condition other than the critical operating condition.

[0035] For example, a normal operating condition refers to an operating state where the remaining compaction time window calculated based on the temperature-viscosity-compactability time window model of the paving material is greater than a preset critical threshold. For instance, the preset critical threshold is determined based on the paving material type, ambient temperature, paving layer thickness design value, and travel speed, and is a specified duration (e.g., 5-15 seconds) and the operation phase is a non-joint overlap phase. A critical operating condition refers to an operating state where the remaining compaction time window is less than or equal to the preset critical threshold, the operation phase is a joint overlap phase, or personnel are detected entering a safe area, or the specified safety-related components of the equipment are found to be abnormal.

[0036] For example, a progressive preemption mechanism can be as follows: When the first component sends a first message of the first priority and detects that the CAN bus is occupied by the second component, determine whether the second message sent by the second component is of the second priority. When the second message is of the second priority type and the first component determines, based on the temperature-viscosity-compactability time window model of the paving material, that the current remaining compactability time window is greater than a preset critical threshold, the first component sends a warning frame carrying a delay transmission duration Δt to the second component; the first type of bit in the message ID of the warning frame identifies the first priority type, and the data field header of the warning frame includes a first sequence, which is used to instruct the second component to complete the transmission of a specified data segment within the Δt and actively release the CAN bus; the Δt is dynamically calculated based on the difference between the remaining compactability time window and the transmission time of the first message, and the Δt is less than a predetermined percentage of the remaining compactability time window; the specified data segment includes the paving layer thickness feedback value and / or screed temperature adjustment confirmation value encoded in the second message; The second component caches the remaining data segments of the second message in the first channel based on the first sequence, and the first message is cached by the second component in the second channel; The third component maintains a listening state on the CAN bus during the Δt period based on the first sequence but does not participate in contention; the first component sends the first message after the second component releases the CAN bus, the tail of the first message carrying a second sequence, the second sequence being used to instruct the second component to resume the transmission of the remaining data segment of the second message within the first duration, the third component not participating in the contention for CAN bus occupancy and resuming listening to the second message within the second duration; the first duration is shorter than the second duration.

[0037] By introducing a delayable transmission duration Δt based on material rheological properties, the rigid control of forced interruption, full buffering and delayed recovery is transformed into a collaborative control of early warning negotiation, segmented transmission and flexible handover. Under the premise of ensuring the critical time window of joint overlap, the loss of critical data segments of low-priority tasks is avoided, and a dynamic balance is achieved between the integrity of real-time feedback on paving quality and the determinism of CAN bus resource scheduling.

[0038] For example, the immediate preemption mechanism can be as follows: When the first component sends a first message of the first priority and detects that the CAN bus is occupied by the second component, it determines whether the second message sent by the second component is of the second priority; when the second message is of the second priority and the first component determines, based on the temperature-viscosity-compactable time window model of the paving material, that the current remaining compactable time window is less than or equal to the preset critical threshold, or when the first component detects that personnel have entered the safe area or that the state of the designated safety associated component of the equipment is abnormal, it immediately performs hardware-layer preemption or application-layer preemption. During the hardware layer preemption, the CAN FD controller of the first component sends a second CAN frame through the CAN bus during the inter-frame gap of the CAN bus. The first type of bit in the message ID of the second CAN frame identifies the first type of priority and is lower than the first type of bit in the message ID of the second message. The second CAN frame is generated based on the first message of the first message. After receiving the second CAN frame, the CAN FD controller of the second component suspends the transmission of the current second type of priority message of the second component and caches the breakpoint information in the hardware buffer. The breakpoint information is used to resume the transmission of the second type of priority message. After receiving the second CAN frame, the CAN FD controller of the third component blocks the CAN bus contention and maintains a listening state for a preset period based on the second duration. During the application layer preemption, the application layer of the first component sends a first application layer message to the CAN controller of the first component. The first application layer message contains a first message, and the header of the first message includes a first sequence. The first sequence is used to instruct the second component to pause the transmission of the second message and cache the received second message in the first channel. The first message is cached in the second channel by each of the functional components. The tail of the first message carries a second sequence, which is used to instruct the second component to resume the transmission of the second message within the first duration. The third component does not participate in the CAN bus occupation contention within the second duration and resumes listening to the second message. The first duration is less than the second duration, and the first duration is dynamically adjusted based on the ratio of the remaining compressible time window to the remaining transmission time of the second message.

[0039] Thus, through a dual-mode preemptive architecture at both the hardware and application layers, the response latency for security emergencies is compressed from milliseconds processed at the application layer to microseconds controlled by the hardware layer. At the same time, by utilizing the priority identifier of the first type of bits in the message ID and the timing control of the first / second sequence, deterministic management of the entire process of preemption triggering, transmission interruption, breakpoint caching, and timed recovery is achieved, breaking through the real-time bottleneck of a single preemptive mode under extreme conditions.

[0040] In some embodiments, the coordination of the two preemption mechanisms can be as follows: The first component dynamically selects between gradual preemption and immediate preemption based on the current paving task stage being executed by the paving equipment and the real-time status of the paving material. When the paving task stage is the joint overlap stage and the remaining compaction time window is greater than the preset critical threshold, gradual preemption is prioritized. When the paving task stage is the regular paving stage or the remaining compaction time window is less than or equal to the preset critical threshold, immediate preemption is prioritized. The preset critical threshold is determined comprehensively based on the type of paving material, ambient temperature, paving layer thickness design value, and the paving equipment's travel speed. After enabling gradual preemption, if the first component detects that the second component has not released the CAN bus within the specified Δt, it automatically switches to immediate preemption. The automatic switching is achieved by marking the first message in the transmission priority queue of the first component's CAN controller as having a preemption attribute, or by sending a preemption trigger command to the application layer of the first component to activate the application layer preemption mechanism.

[0041] In this way, by constructing a mapping relationship between paving task stages, material status windows and preemption modes, the statically preset priority rules are upgraded to a dynamic and adaptive scheduling strategy, so that the allocation of CAN bus communication resources and paving process quality form a closed loop coupling, ensuring the continuity of operation under normal working conditions and ensuring structural safety under critical working conditions, and realizing the collaborative optimization of communication reliability and construction quality consistency in multi-machine collaborative unmanned paving.

[0042] In some embodiments, multiple priority levels refer to a mechanism for classifying and sorting messages based on their importance and urgency. In this embodiment, messages are divided into a first priority level and a second priority level. The first priority level is typically related to key indicators of safe equipment operation and paving tasks, such as emergency stop commands and critical parameter alarms, and its transmission requires extremely high real-time performance and reliability. The second priority level is related to routine paving operation control, such as speed adjustment and paving width adjustment, and its real-time requirements are relatively lower.

[0043] The first, second, and third messages are specific data packets sent by different functional components on the CAN bus in this embodiment. These messages carry sensor data, control commands, status information, etc., and their priority and content depend on the specific communication scenario and functional components.

[0044] The first sequence and the second sequence are data fields embedded in the header or footer of a specific message. The first sequence is used to instruct the receiver to perform specific operations, such as pausing the transmission of the current message and buffering received messages into a designated channel. The second sequence is used to instruct the receiver to resume operation after a specific period of time and may involve CAN bus contention behavior of other components.

[0045] The first and second channels are internal buffers within the functional component used for temporary storage of received messages. By storing different types of messages or messages in different states in different channels, effective message management and processing can be achieved, avoiding data loss or confusion.

[0046] The first and second durations are parameters used to control the recovery time of specific operations. These duration parameters are set to coordinate the communication behavior between different functional components, ensuring the timely transmission of high-priority messages while avoiding unnecessary long interruptions to low-priority messages. The first duration being shorter than the second duration reflects the differentiated strategies employed by different components when responding to high-priority messages.

[0047] This embodiment provides a multi-machine collaborative unmanned paving control method based on a CAN bus. The method is executed by a first paving device, which integrates multiple functional components connected via a CAN bus. The CAN bus, as an efficient and reliable communication medium, ensures real-time data exchange between the components within the device. These functional components may include, but are not limited to, sensors, actuators, wireless communication modules, and controllers. Specifically, sensors are responsible for collecting operational environment and equipment status data; actuators are responsible for performing physical operations according to instructions; wireless communication modules are responsible for wireless communication with other external devices; and the controller, as the core processing unit, coordinates the work of each component. The first, second, and third components are exemplary classifications of these functional components, used to describe the interactive behavior of different components in CAN bus communication.

[0048] In this control method, multiple priorities are assigned to different types of messages based on the paving task currently being performed by the first paving equipment. This prioritization mechanism aims to ensure the priority transmission of critical information. Specifically, these priorities can be divided into a first-class priority and a second-class priority. The first-class priority is set to be closely related to the key primary indicators of equipment operation safety and the paving task, such as emergency braking commands or parameters related to the structural integrity of the paved layer. The second-class priority is set to be related to routine paving operation control, such as paving speed adjustment or material flow control. Through this classification, the system can differentiate the processing of messages according to their importance.

[0049] When the first component needs to send a first message with a first priority class, it first listens to the status of the CAN bus. If it detects that the CAN bus is currently being used by a second component, and the second component is sending a second message, the system further determines the priority type of that second message. This step is crucial for implementing intelligent CAN bus arbitration, aiming to avoid blind waiting or disorderly preemption, thereby optimizing the efficiency of bus resource utilization.

[0050] If it is determined that the second message sent by the second component belongs to the second priority category, meaning its importance is lower than the first message of the first priority category to be sent by the first component, the first component will immediately send the first message. To ensure the smooth transmission of the first message and coordinate the behavior of other components, the header of the first message is designed to contain a first sequence. The purpose of this first sequence is to instruct the second component sending the second message to pause its current message transmission and to instruct any functional component that has received the first message to buffer the received first message in the first channel. Simultaneously, the first message itself will be buffered in the second channel by each functional component. When the last message of the first message is sent, its tail will carry a second sequence. This second sequence is used to instruct the second component to resume its message transmission within a first duration and to instruct the third component not to participate in CAN bus occupancy contention within the second duration and to resume listening to the CAN bus. It is worth noting that the first duration is set to be shorter than the second duration. This differentiated duration setting aims to finely control the response behavior of different components, ensure the timely processing of high-priority messages, and provide a reasonable buffer for the recovery of other components.

[0051] On the other hand, if it is determined that the second message sent by the second component also belongs to the first priority category, meaning its importance is equivalent to the first message to be sent by the first component, then the first component will not immediately preempt the bus. In this case, the first component will wait for the second component to complete sending its second message of the first priority category. Once the bus is idle, the first component will participate in the CAN bus contention based on its first priority category to ensure that its first message can also be sent at the appropriate time. This strategy avoids conflicts between messages of equal importance and maintains the order of bus communication.

[0052] When the first component needs to send a third message with a second-priority level and detects that the CAN bus is currently occupied by the second component, the first component will adopt a waiting strategy. Specifically, the first component will wait for the second component to complete sending its second message. Once the bus is idle, the first component will participate in the CAN bus contention based on its own second-priority level to send the third message. This ensures that low-priority messages can also obtain bus resources without interfering with high-priority communication.

[0053] In this method, the wireless communication module is configured to continuously monitor communications on the CAN bus. Once the wireless communication module detects any message with a first-priority message, it immediately transmits that first-priority message wirelessly to the second paving device. This mechanism ensures that critical information related to safety and mission-critical indicators can be shared in real time among multiple paving devices, thereby enabling efficient multi-machine collaborative operation.

[0054] The control method proposed in this embodiment effectively solves the problems of inconsistent communication and poor real-time performance among multiple devices in traditional paving operations by deploying a CAN bus within the paving equipment and introducing a multi-level message priority mechanism. This method can intelligently determine bus occupancy and perform refined arbitration based on message priority, ensuring the priority transmission of messages related to safety and critical task indicators, significantly improving the real-time performance and reliability of communication. Furthermore, by forwarding high-priority messages to other paving equipment in real time through a wireless communication module, effective linkage and coordination between multiple machines are achieved, avoiding operational problems such as material shortages and pressure leaks. This improves the overall efficiency and quality of paving operations, reduces the need for manual intervention, and enhances the intelligence level of unmanned paving operations.

[0055] To address this issue, this application proposes a multi-machine collaborative unmanned paving control method based on a Controller Area Network (CAN) bus. This method is executed by a first paving device, which includes multiple functional components connected via the CAN bus. These components specifically include sensors, actuators, wireless communication modules, and controllers. The method can set multiple priority levels for different message types based on the paving task currently being performed by the paving device. These priority levels include a first priority level and a second priority level. The first priority level is related to safety and a first indicator of the paving task, while the second priority level is related to paving operation control. When the first component sends a first message of the first priority level and detects that the CAN bus is occupied by the second component, the system determines whether a second message sent by the second component is of the second priority level. If the second message is of the second priority type, then the first message is sent. The header of the first first message includes a first sequence, used to instruct the second component to pause the transmission of the first message, and for each functional component to buffer the received second message in the first channel; the first message is buffered by each of the functional components in the second channel; the tail of the last first message carries a second sequence, used to instruct the second component to resume the transmission of the first message within a first duration, and the third component not to participate in the CAN bus occupation contention and to resume listening to the first message within the second duration; the first duration is less than the second duration. If the second message is of the first priority type, then the competition for the CAN bus is based on the second priority type after the second component finishes sending the second message. When the first component has a third message of the second priority type to send and listens that the CAN bus is occupied by the second component, it waits for the second component to finish sending the second message and then competes for the CAN bus based on the second priority type. In addition, after the wireless communication module listens to a message of the first priority type on the CAN bus, it will wirelessly send the message of the first priority type to the second paving device.

[0056] In some of the embodiments described above in this application, a mechanism has been proposed to set a first priority category and a second priority category based on message type, and to perform CAN bus arbitration based on this. However, in actual unmanned paving operations, the urgency and importance of different types of safety messages, multi-machine collaboration messages, and job control messages may vary significantly. Simply dividing messages into two priority categories may result in truly urgent critical messages failing to preempt the bus in a timely manner within a certain priority category, or secondary messages unnecessarily delaying the transmission of more important similar messages, thereby affecting the system's real-time response capability and overall operational efficiency.

[0057] In response, this application further refines the aforementioned first and second priority categories. Specifically, the first priority category includes at least a first-class highest priority, a first-class second-highest priority, and a first-class lowest priority. The first-class highest priority is used for messages related to personnel safety and designated equipment safety; the first-class second-highest priority is used for messages related to multi-machine collaboration; and the first-class lowest priority is used for messages related to a first indicator of the currently performed paving task, where the first indicator includes structural indicators of the paving layer. Simultaneously, the second priority category includes a second-class highest priority, a second-class second-highest priority, and a second-class lowest priority. The second-class highest priority is used for messages related to a second indicator of the currently performed paving task, where the second indicator is a non-structural indicator of the paving layer and / or equipment performance indicators; the second-class second-highest priority is used for messages related to equipment operating efficiency adjustment; and the second-class lowest priority is used for messages related to multi-machine collaborative assistance.

[0058] Specifically, the first category, with the highest priority, is designated as the highest priority level and is specifically used to transmit emergency messages that directly relate to the safety of personnel and the operational safety of the paving equipment itself. These messages may include emergency stop commands, obstacle detection alarms, fault alarms for critical equipment components (such as engine overheating or abnormal hydraulic system pressure), and abnormal sensor data (such as temperature or pressure exceeding safety thresholds). By granting these messages the highest transmission authority, it ensures that they can be sent, received, and processed in the shortest possible time, thereby minimizing the occurrence of accidents or reducing potential losses to the lowest possible level.

[0059] In some embodiments, the CAN bus has a preemption mechanism; the method further includes: when the preemption mechanism is activated, allowing the transmission of messages of the first priority to preempt the transmission of messages of the second priority to occupy the CAN bus; when the preemption mechanism is deactivated, prohibiting the transmission of messages of the first priority to preempt the transmission of messages of the second priority to occupy the CAN bus.

[0060] For example, configure the preemption mechanism state (activated / deactivated) of the CAN bus.

[0061] By default, the CAN bus preemption mechanism is active (meaning that high-priority messages are allowed to actively interrupt the transmission of low-priority messages). This state is suitable for high-risk scenarios in paving operations (such as equipment approaching personnel, or paving layer thickness deviation exceeding a safety threshold), and it is necessary to ensure that first-priority messages (such as emergency braking commands and critical component fault alarms) can preempt bus resources in real time.

[0062] In specific low-risk scenarios (such as when paving operations have entered a stable phase and equipment is only performing routine speed adjustments), the system can manually or through an AI model determine whether to deactivate the preemption mechanism. In this state, first-priority messages must wait for second-priority messages to complete their current transmission before competing for the bus based on priority, thus avoiding frequent preemption that could disrupt normal operation control processes.

[0063] In some embodiments, high-risk scenarios may be classified as Category I work scenarios, and low-risk scenarios as Category II work scenarios. Category I and Category II work scenarios can be predicted and analyzed by AI models based on the current work environment and work mode (e.g., single-machine operation or machine-coordinated operation), the distance between the work site and residential areas, and other factors.

[0064] The system monitors the preemption mechanism status and controls message transmission priority. When the preemption mechanism is activated, if the first component (such as a safety monitoring sensor) needs to send a first message of the first priority (e.g., "personnel have entered a dangerous area"), and the CAN bus is currently being used by the second component (such as a paving speed controller) to transmit a second message of the second priority (e.g., "paving speed fine-tuned to 1.8 m / min"), the system will allow the first message to interrupt the transmission of the second message through the preemption mechanism. Specifically, the header of the first message contains a first sequence, instructing the second component to pause the transmission of the current second message and cache the received portion of the first message in the first channel (internal cache of each functional component). The last first message carries a second sequence, instructing the second component to resume transmission within a preset short duration (e.g., 50 ms). The third component (such as an actuator) does not participate in bus contention and resumes listening for a longer duration (e.g., 100 ms).

[0065] When the preemption mechanism is deactivated, even if the first component sends a first message of first priority (e.g., "slight deviation in paving thickness requires adjustment of scraper height"), and the CAN bus is being used by the second component to transmit a second message of second priority (e.g., "optimization of screw feeder speed"), the system prohibits the first message from actively interrupting the transmission of the second message. The first component must wait for the second component to complete sending its current second message before competing for bus resources based on the regular competition rules between first and second priorities (e.g., first priority takes precedence over second priority, but requires queuing to wait for the bus to become available).

[0066] In some embodiments, the preemption mechanism state is dynamically adjusted. For example, the controller can dynamically adjust the preemption mechanism state based on the real-time operation status: for example, when the AI ​​model detects that the paving layer thickness deviation exceeds the emergency threshold (e.g., >2cm), the preemption mechanism is automatically activated to ensure that the first priority message "emergency adjustment of scraper height" is transmitted first; when the deviation returns to a safe range (e.g., <0.5cm), the preemption mechanism is deactivated, allowing the second priority message (e.g., "continuous optimization of paving speed") to be transmitted stably to maintain operation efficiency.

[0067] In high-risk scenarios, the preemption mechanism is activated to ensure that priority messages (such as personnel safety and critical equipment failures) can interrupt the transmission of non-emergency operation control messages in real time, thus avoiding safety accidents or quality defects caused by bus delays.

[0068] In low-risk scenarios, the preemption mechanism is activated to allow stable transmission of second-priority messages (such as fine-tuning of paving speed and equipment status feedback), reducing unnecessary preemption interference and maintaining the continuity and efficiency of the work process.

[0069] By dynamically adjusting the preemption mechanism (such as automatically switching based on paving thickness deviation and equipment malfunction), the system can intelligently balance the needs of safety and efficiency at different operation stages, thereby improving the level of intelligence in multi-machine collaborative unmanned paving.

[0070] After deactivating the preemption mechanism, the CAN bus executes the traditional non-preemptive communication protocol (queuing by priority, with high-priority devices only competing for idle bus space and low-priority devices not being interrupted), which is compatible with traditional CAN 2.0 devices (such as old sensors and third-party controllers) without requiring hardware / software modifications. It ensures stable transmission of routine operation messages (such as speed fine-tuning and status feedback) and avoids delays or interruptions caused by preemption. It simplifies the bus arbitration logic, reduces the controller's computing power requirements and system failure risks, and supports flexible switching according to scenarios (high-risk activation / low-risk deactivation), balancing security and efficiency and improving the adaptability of multi-machine collaboration.

[0071] The activation and / or deactivation of the application-layer and hardware-layer preemption mechanisms are described below. The activation and deactivation of the application-layer preemption mechanism are implemented through software configuration. Activation enables message buffering and sequence scheduling logic; deactivation disables the corresponding logic and restores the standard message sending process. The activation and deactivation of the hardware-layer preemption mechanism are implemented through configuring the relevant registers of the standard CANFD controller. Activation enables inter-frame interval detection and high-priority message scheduling; deactivation disables this hardware scheduling function and restores the standard bus arbitration mode. When the preemption mechanism is fully activated, the operating system prioritizes the application-layer preemption mechanism. If the application-layer preemption mechanism cannot meet real-time requirements, it automatically switches to the hardware-layer preemption mechanism. When the preemption mechanism is deactivated, the application layer preemption mechanism and the hardware layer preemption mechanism are simultaneously shut down. The CAN bus resumes standard non-preemptive communication. High-priority messages only participate in arbitration competition after the bus is idle, and interrupt-based preemption scheduling is no longer executed. By adopting a progressive execution order of application layer preemption followed by hardware layer preemption, the real-time performance of message transmission can be improved while ensuring compatibility and stability, reducing unnecessary bus scheduling fluctuations. It can maintain a reliable communication state in both routine operations and emergency safety scenarios, and better adapt to the operational needs of multi-machine collaborative unmanned paving.

[0072] The first category, second-highest priority, is used to handle coordination and synchronization messages between devices in multi-machine collaborative operations. For example, when multiple paving machines are operating in a convoy, commands for adjusting queue positions, speed synchronization, path planning updates, sharing of work area boundaries, and emergency avoidance notifications are required. These messages are crucial for maintaining the overall efficiency of multi-machine operations, avoiding collisions, and ensuring operational continuity. Their urgency is slightly lower than direct personnel or equipment safety messages, but a high degree of real-time transmission is still necessary.

[0073] The first category, with the lowest priority, is used to transmit messages related to the structural parameters of the paving layer for the currently performed paving task. These structural parameters typically refer to parameters affecting core pavement performance such as load-bearing capacity and durability, including paving thickness, compaction degree, material uniformity, and temperature gradient. These messages may include real-time thickness measurement data, compaction degree feedback, and material composition analysis results. While these messages are crucial for paving quality, their urgency is generally lower than immediate safety and multi-machine coordination commands, allowing for some buffering or waiting to avoid competing for bus resources with more urgent messages.

[0074] In the second priority category, the highest priority is used to transmit messages related to non-structural parameters of the paving layer and / or equipment performance parameters. Non-structural parameters of the paving layer may include surface smoothness, texture, and color, which affect the comfort and aesthetics of the pavement. Equipment performance parameters may include engine speed, hydraulic pump pressure, track speed, and fuel consumption. These messages are crucial for optimizing operational efficiency and monitoring equipment health, requiring timely processing to adjust operational parameters, but their urgency is lower than any messages in the first priority category.

[0075] The second category, with slightly higher priority, is used for messages related to adjusting equipment operating efficiency. These messages may include dynamically adjusting parameters such as paving speed, vibration frequency, and screed heating temperature based on current work progress, material supply, and environmental conditions to achieve optimal work efficiency and energy consumption. These adjustments are typically based on long-term data analysis and optimization models, and while they have a certain real-time requirement, they are not urgent.

[0076] The second category, with the lowest priority, is used for transmitting auxiliary messages in multi-machine collaborative operations. These messages may include equipment status reports (non-urgent), log information, software version update notifications, non-critical diagnostic data, and environmental parameters (such as temperature and humidity, which do not directly affect safety or structural indicators). These messages are valuable for system maintenance, troubleshooting, and long-term performance optimization, but their real-time transmission requirements are the lowest, and they can be sent when the CAN bus is idle.

[0077] Through the above technical solution, this application can assign more precise priority levels to messages based on their actual importance and urgency. By further refining the division between the first and second priority categories, communication resources on the CAN bus can be utilized more rationally and efficiently.

[0078] For example, in the first priority category, messages related to personnel safety and equipment safety are set to the highest priority. This ensures that in emergencies, these most critical safety information can prioritize the CAN bus and be transmitted rapidly, effectively preventing or mitigating accidents. Messages related to multi-machine collaboration are given the second highest priority, ensuring the synchronization and coordination of multiple devices during collaborative operations, improving overall operational efficiency and safety. While messages related to the structural indicators of the paving layer are important, their urgency is relatively low, and they are set to the lowest priority to avoid resource competition with more urgent messages.

[0079] Similarly, in the second priority category, messages related to non-structural indicators of the paving layer and equipment performance indicators are given the highest priority. This ensures that critical information regarding work quality and equipment health is processed in a timely manner, thereby enabling refined control of paving operations and real-time monitoring of equipment status. Messages related to equipment operating efficiency adjustment are given the second highest priority, helping the system dynamically adjust operating parameters and optimize resource allocation based on actual conditions. Messages related to multi-machine collaborative assistance are set to the lowest priority, allowing them to be transmitted without affecting critical communication. This refined priority management mechanism enables more rational and efficient use of CAN bus resources, ensuring the real-time nature and reliability of critical information while also considering the transmission needs of non-critical information, significantly improving the overall performance, safety, and operational efficiency of the multi-machine collaborative unmanned paving control system.

[0080] In some embodiments described above in this application, a multi-machine collaborative unmanned paving control method based on a Controller Area Network (CAN) bus is proposed. This method manages communication on the CAN bus by setting different message priorities to ensure the timely transmission of safety and mission-critical messages. However, in actual implementation, when multiple functional components send a large number of messages of different types and priorities on the CAN bus, efficiently and accurately identifying the type and priority of each message and ensuring its correct processing in the CAN bus arbitration mechanism is a key challenge to ensuring the real-time performance and reliability of the system. If the message identifier is unclear or lacks structured features, functional components may find it difficult to quickly determine the importance of the received message, thereby affecting the timely processing of messages and the overall response speed of the system.

[0081] In some embodiments, the method further includes: Based on the equipment status monitoring information of the paving equipment, determine whether the status of the non-designated safety-related components of the paving equipment is abnormal; When the state of the non-designated security associated component is abnormal, the priority of non-device-designated security-related messages is increased from the second priority category to the first priority category.

[0082] In some embodiments, Equipment safety specifications refer to safety factors directly related to safety components in paving equipment that are closely linked to personnel safety (such as emergency braking devices and guardrails) and key operational functions that ensure the most basic structural indicators of the paved layer (such as paving thickness and compaction). Examples include a paver's emergency braking device malfunctioning or the paved layer thickness deviating significantly from design standards, affecting the road's load-bearing capacity.

[0083] Non-equipment-specified safety: This refers to factors that do not involve personnel safety or the most basic structural indicators of the paving layer, but may affect auxiliary functions of paving operations (such as material conveying efficiency and equipment cleanliness), adaptability to the operating environment (such as equipment operation at different temperatures), and long-term healthy operation of the equipment (such as wear of non-critical components). Examples include unstable conveyor belt motor speed affecting material conveying speed, difficulty in starting the paver in low-temperature environments, and minor corrosion of non-critical parts of the equipment.

[0084] Thus, the first priority category (e.g., highest / second-highest / lowest priority) primarily relates to personnel safety, designated equipment safety, and core indicators of the paving task (e.g., structural parameters of the paving layer), while the second priority category (e.g., highest / second-highest / lowest priority) covers non-safety-related operational control or auxiliary information (e.g., status of non-core equipment components, environmental monitoring data, etc.). However, in actual operations, abnormal status of non-designated safety-related components of the paving equipment (e.g., hydraulic pump auxiliary pipelines, conveyor belt motors, concrete spreader drive modules, etc.) may indirectly lead to equipment performance degradation, paving quality defects, or even safety hazards (e.g., overheating of the conveyor belt motor causing material conveying interruption, indirectly resulting in uneven paving layer thickness; jamming of the concrete spreader drive module affecting paving uniformity, and long-term operation may exacerbate mechanical wear). If such abnormalities are only processed as second-priority messages, the response may be delayed due to bus contention, ultimately affecting the continuity or quality of operations. Therefore, based on the patent documents, this embodiment further proposes to monitor the status of non-designated safety-related components in real time, identify anomalies, and elevate the corresponding second-priority messages to first-priority messages. This ensures the real-time transmission and processing of critical anomaly information, improving the reliability and intelligence level of paving operations. When elevating the priority of non-equipment-designated safety messages from the second-priority to the first-priority, they can be initially elevated to the lowest priority level of the first-priority category. Then, based on the operating status of the detection equipment, it is determined whether further gradual or skip-level elevation of their priority level within the first-priority category is necessary.

[0085] This application further proposes that the messages sent by each functional component include a message identifier ID. The message identifier ID is a field used to uniquely identify messages in CAN bus communication, and its value directly determines the arbitration priority of the message on the CAN bus; the smaller the value, the higher the priority. The message ID includes a type ID and a serial number (SN) following the type ID. The type ID is a specific segment in the message ID used to classify messages, such as distinguishing between safety messages, control messages, and diagnostic messages. By assigning different type IDs to different types of messages, the receiving functional component can quickly identify the message category and perform corresponding processing accordingly. The SN is another segment in the message ID, immediately following the type ID, used to distinguish different message instances under the same type ID. For example, if a sensor continuously sends multiple temperature data points, they may have the same type ID, but each data packet will carry an incrementing SN so that the receiver can identify the message order or distinguish different data samples.

[0086] The type ID further includes a first type of bit and a second type of bit. The first type of bit is the higher-order bit of the second type of bit. The first type of bit can have multiple bits. The second type of bit can also have multiple bits. This bit allocation method ensures that the higher-level priority classification represented by the first type of bit plays a decisive role in the CAN bus arbitration process. Specifically, the first type of bit corresponds to different priorities. For example, the first type of bit for a first-priority message representing safety and paving task indicators can be set to a lower value (e.g., "000"), while the first type of bit for a second-priority message representing paving operation control can be set to a higher value (e.g., "001"). Since smaller values ​​indicate higher priority in the CAN bus arbitration mechanism, first-priority messages will naturally gain priority in bus arbitration. Simultaneously, the second type of bit for different priority levels of the same type is different. This means that within the same major priority category (determined by the first type of bit), priority levels can be further subdivided using the second type of bit. For example, in first-priority messages, the second type of bit for the highest priority message can be set to "100", the second highest priority message to "101", and the lowest priority message to "111". In this way, even if two messages belong to the first priority category, their internal priority levels can be distinguished by the second type of bits, thereby achieving more granular priority management.

[0087] The message ID is used by each functional component to determine the message type of the received message. When a functional component receives a message on the CAN bus, it parses its message ID. By parsing the type ID in the message ID, the functional component can quickly determine the message category, such as whether it is a safety command, sensor data, or control parameter. This rapid identification capability is crucial for unmanned paving systems with high real-time requirements. The SN is used to distinguish different messages. When receiving messages with the same type ID, the functional component can use the SN to determine whether the message is a duplicate, whether it is the next message in a sequence, or whether specific sequence processing is required.

[0088] Through the above technical solution, this application employs a structured design for CAN bus message IDs, directly encoding message priority and type information into the message ID, thereby fully utilizing the inherent arbitration mechanism of the CAN bus. This design allows high-priority messages (such as first-priority messages) to automatically gain priority in bus contention, eliminating the need for complex software arbitration logic and significantly improving the real-time transmission efficiency and determinism of critical messages. Each functional component can quickly identify message type and priority based on the structured message ID, achieving efficient message filtering and processing and avoiding system response delays caused by message identification latency. Furthermore, distinguishing messages of the same type using the SN further enhances communication reliability and data integrity, aiding the receiving functional components in message sequence management and duplicate message detection. Overall, this solution effectively addresses the challenges of message identification and priority management for multi-functional components in CAN bus communication, improving the real-time performance, reliability, and safety of the multi-machine collaborative unmanned paving control system.

[0089] In some embodiments described above in this application, a multi-machine collaborative unmanned paving control method based on a Controller Area Network (CAN) bus is proposed. This method optimizes communication efficiency and response speed on the CAN bus by setting multiple priorities for different types of messages. However, in actual unmanned paving operations, relying solely on message priority management may be insufficient to cope with complex changes in the operating environment, fluctuations in the properties of paving materials, and sudden safety events. This makes it difficult to guarantee the real-time performance and accuracy of control parameters, thereby affecting paving quality and operational safety.

[0090] In response, this application further proposes a method, which further includes: the controller determining control parameters based on the paving material information, first working environment information, and equipment operating status collected by the sensors using an artificial intelligence (AI) module; the control parameters being used to control the operation of the paving equipment; cross-verifying the working location based on satellite positioning information and local positioning information from a local wireless positioning module to obtain verified positioning information; generating time-sequential control commands based on the verified positioning information and the control parameters; distributing the time-sequential control commands sequentially via the CAN bus; and generating an interrupt signal when the controller receives a message of the first priority type, suspending the processing of the time-sequential control commands based on the interrupt signal, and prioritizing the processing of the interrupt signal.

[0091] Specifically, the controller is the core control unit of the paving equipment, responsible for receiving and processing various types of data and issuing control commands. The artificial intelligence (AI) module can be a software module or hardware acceleration unit integrated into the controller, running a trained machine learning model, such as a deep neural network, fuzzy logic system, or expert system. This AI module can analyze in real time the paving material information (e.g., material temperature, humidity, composition, particle size distribution), the initial working environment information (e.g., ambient temperature, humidity, wind speed, ground slope, obstacle information), and the equipment operating status (e.g., paving speed, vibration frequency, screed temperature, engine speed, hydraulic system pressure), collected by the sensors. Through comprehensive analysis and pattern recognition of this multi-source heterogeneous data, the AI ​​module can dynamically determine the optimal control parameters, such as paving thickness, width, speed, vibration frequency, screed heating temperature, and material delivery rate, to adapt to constantly changing working conditions and ensure paving quality.

[0092] To obtain high-precision operational location information, this application employs a cross-validation mechanism. The satellite positioning information is typically provided by a Global Navigation Satellite System (GNSS) or BeiDou satellite system receiver, including the device's global coordinates such as latitude, longitude, and altitude. The local wireless positioning module can utilize technologies such as Ultra-Wideband (UWB), Wi-Fi, Bluetooth, or RFID to provide high-precision relative positioning information within a local area. By fusing and comparing the satellite positioning information with the local positioning information from the local wireless positioning module—for example, using Kalman filtering, particle filtering, or multi-sensor fusion algorithms—errors that may exist in a single system can be effectively eliminated, improving the accuracy and robustness of positioning, thereby obtaining verified positioning information.

[0093] In some embodiments, when paving a wide road surface in parallel using two pavers, each paving machine is equipped with three sets of UWB modules, and the relative positions between the machines are obtained through TOF ranging. The UWB data is cross-validated with BeiDou positioning data to compensate for drift errors caused by BeiDou multipath effects, and the controller adjusts the lateral position in real time based on the fused positioning data.

[0094] After obtaining accurate and verified positioning information and optimal control parameters determined by the AI ​​model, the controller generates a series of time-sequential control commands. These commands are arranged according to a predetermined time sequence or work flow sequence to precisely drive various actuators on the paving equipment, such as the hydraulic system, vibratory compaction mechanism, screed heating system, and steering system. These commands are designed to trigger corresponding actions at specific time points or work stages to achieve precise paving operations.

[0095] The generated timing-based control commands are distributed to the corresponding actuators via the CAN bus in a timely manner. As a reliable fieldbus, the CAN bus ensures that these commands are accurately transmitted to the target functional components in a predetermined order and time interval, thereby guaranteeing the coordinated operation of each actuator and achieving smooth and efficient paving work.

[0096] To address emergencies or handle critical tasks, this application introduces an interruption mechanism. When the controller receives a message of the first priority type (e.g., a message related to personnel safety, equipment safety specifications, or paving layer structural indicators), it immediately generates an interruption signal. This interruption signal preempts the generation or transmission of regular time-sequential control commands currently being executed by the controller, paving it off. The controller then immediately prioritizes processing the high-priority message that caused the interruption, such as performing safety or mission-critical operations like emergency braking, obstacle avoidance, or adjusting critical parameters. This mechanism ensures that the system can react quickly in emergency or critical situations, avoiding potential safety risks or significant mission deviations.

[0097] Through the aforementioned technical solution, this application introduces an artificial intelligence (AI) module, enabling the controller to comprehensively analyze paving material information, initial working environment information, and equipment operating status collected by sensors. This allows for real-time and precise determination of control parameters adapted to the current working conditions, significantly improving the intelligence and adaptability of the control, thereby ensuring the quality and efficiency of the paving operation. Simultaneously, cross-validation of satellite positioning information and local positioning information from the local wireless positioning module effectively improves the accuracy and reliability of the working location information, providing a solid foundation for accurately generating time-sequential control commands. More importantly, when the controller receives a message with the highest priority, it can immediately generate an interrupt signal and pause the processing of regular time-sequential control commands, prioritizing the response to and processing of these safety- and mission-critical messages. This mechanism ensures that the system can react quickly in emergency or critical situations, avoiding potential safety risks or significant mission deviations. It greatly enhances the safety, reliability, and real-time response capabilities of unmanned paving operations, effectively compensating for the shortcomings of relying solely on message priority management in terms of control accuracy and safety response under complex working conditions.

[0098] In some embodiments described above in this application, the controller, based on an artificial intelligence (AI) module, uses information on the paving material, the first working environment, and the equipment operating status collected by sensors to determine control parameters and generate time-sequential control commands to control the operation of the paving equipment. However, in actual operation, sensors may have acquisition errors or drift, and the complexity of the working environment may make it difficult to fully consider its impact on the operating status of the paving equipment in the initial control parameters, thereby potentially affecting the accuracy of the control parameters and the stability of the operation results.

[0099] To address this, this application further proposes a controller based on an artificial intelligence (AI) module, utilizing paving material information and secondary operational environment information to determine calibration parameters. Specifically, the controller can integrate or invoke an AI module capable of using machine learning, deep learning, and other algorithms to analyze and model historically or real-time acquired paving material information (e.g., material temperature, humidity, viscosity, particle size distribution) and secondary operational environment information (e.g., ambient temperature, humidity, wind speed, ground temperature, roadbed conditions). Through this analysis, the AI ​​module can identify deviation patterns between sensor data and actual conditions, or the influence of environmental factors on sensor performance, thereby generating a series of calibration parameters for correcting the sensor-collected data. These calibration parameters can be simple offsets or gain coefficients, or complex calibration curves or predictive models.

[0100] After obtaining the calibration parameters, this application calibrates the sensor's acquisition parameters based on these parameters. The sensor's acquisition parameters refer to the raw or pre-processed data actually output by the sensor. By applying the calibration parameters generated by the aforementioned artificial intelligence (AI) module, these acquisition parameters can be corrected or compensated in real time. For example, if the calibration parameters indicate that a certain temperature sensor is typically 2 degrees Celsius below the current ambient temperature, the controller will add 2 degrees Celsius to the sensor's real-time reading to obtain more accurate material temperature information. This calibration process ensures that the basic data upon which subsequent control decisions rely has higher accuracy and reliability.

[0101] Simultaneously, this application also identifies the impact parameters of the operating environment indicated by the second operating environment information on the operating status of the paving equipment. In addition to calibrating sensor data, the AI ​​module further analyzes the second operating environment information to quantify the specific impact of these environmental factors on the operating status of the paving equipment (e.g., paving speed, vibration frequency, screed temperature, compaction effect, etc.). For example, the AI ​​module can build models to predict how the cooling rate of the paving material will change under specific wind speeds and ambient temperatures, or how the required compaction energy should be adjusted under different subgrade hardnesses. These quantified impact parameters can be expressed as correction factors, weighting coefficients, or dynamic adjustment rules, which together constitute the "shadow of impact" on the environment.

[0102] Finally, this application calibrates the operation control parameters based on the calibrated acquisition parameters and the influence shadow. After obtaining the precisely calibrated sensor acquisition parameters and quantified environmental influence parameters (i.e., influence shadow), the controller inputs this more accurate and comprehensive information into the artificial intelligence (AI) module to perform secondary calibration or optimization of the original operation control parameters. For example, if the calibrated material temperature is lower than expected, and the influence shadow indicates that low temperature will accelerate material cooling, the AI ​​module will adjust the screed heating power or paving speed accordingly to ensure that the paving quality meets the requirements. This dynamic and intelligent calibration mechanism enables the operation control parameters to adapt to material characteristics and environmental changes in real time, thereby achieving more refined and stable paving operations.

[0103] Through the above technical solution, the controller can utilize an artificial intelligence (AI) module to perform in-depth analysis of paving material information and secondary operating environment information, generating calibration parameters to accurately calibrate the sensor-collected parameters, significantly improving the accuracy of input data. Simultaneously, by determining the parameters affecting the operating environment's impact on the paving equipment's operational status, the controller can more comprehensively understand the potential influence of external conditions on equipment performance. Based on this, a secondary calibration of the operation control parameters ensures the accuracy and adaptability of control commands, effectively avoiding control deviations caused by sensor errors or environmental changes, thereby improving the quality stability, efficiency, and equipment reliability of paving operations.

[0104] In some of the embodiments described above in this application, in order to obtain verified positioning information, it is necessary to perform cross-verification of the work location based on satellite positioning information and local positioning information from a local wireless positioning module. However, in actual paving operations, a single local wireless positioning module may provide insufficient accuracy or poor stability of the local positioning information due to factors such as environmental complexity, signal obstruction, or multipath effects, thereby affecting the accuracy of subsequent positioning verification and the generation of control commands.

[0105] In response, this application further proposes that the local wireless positioning module includes multiple modules distributed at different locations on the paving equipment; the method further includes: obtaining local positioning information based on the positioning information of any two local wireless positioning modules and the distance between the two local wireless positioning modules.

[0106] Specifically, the local wireless positioning module comprises multiple modules, strategically distributed at different locations on the paving equipment. For example, local wireless positioning modules can be installed in key areas such as the front, middle, rear, or sides of the paving equipment. This multi-module configuration aims to increase the coverage and redundancy of the positioning signal, reducing the risk of a single module failing due to local environmental interference or obstruction. Each local wireless positioning module can employ one or a combination of wireless positioning technologies such as Ultra-Wideband (UWB), Wi-Fi, Bluetooth Low Energy (BLE), or Radio Frequency Identification (RFID) to adapt to different operating environments and accuracy requirements. By deploying in different locations, positioning signals can be received and processed from multiple angles, providing a richer and more reliable data source for subsequent positioning calculations.

[0107] Based on this, local positioning information can be obtained using the positioning information of any two local wireless positioning modules and the distance between them. Specifically, since the paving equipment is a rigid or semi-rigid structure, the physical distance between each local wireless positioning module is known in advance and relatively fixed. When at least two local wireless positioning modules each obtain their positioning information relative to an external reference point or to each other, this information and their known geometric relationships (distances) can be used to verify, fuse, or optimize the positioning results of individual modules through algorithms such as triangulation, polygonal measurement, or differential positioning, thereby calculating a more accurate and stable overall local positioning information for the paving equipment. This method can effectively eliminate or reduce the measurement errors that may exist in individual modules, improving the overall accuracy and reliability of local positioning.

[0108] By deploying multiple local wireless positioning modules on the paving equipment and distributing them at different locations, and using the positioning information of any two modules and their spacing to obtain local positioning information, this application effectively solves the problem of insufficient positioning accuracy and robustness of a single local wireless positioning module in complex operating environments. The collaborative work of multiple modules provides redundancy and diversity of positioning information. Even if some modules are interfered with or obstructed, compensation can still be made through data from other modules, significantly improving the accuracy and stability of local positioning information. This optimized local positioning information can be more reliably cross-validated with satellite positioning information, thereby obtaining more accurate and robust validated positioning information. Furthermore, based on this validated positioning information and the control parameters determined by the controller, more precise time-sequential control commands can be generated, ensuring more refined and stable operation control of the paving equipment, and improving the overall quality and efficiency of paving operations.

[0109] In some of the above embodiments, satellite positioning information and local positioning information from a local wireless positioning module are used for cross-verification to obtain accurate work location information. However, in actual working environments, satellite signals are easily affected by multipath effects, leading to a decrease in the accuracy of satellite positioning information. This, in turn, affects the accuracy of the verified positioning information and the control parameters and timing control commands generated based on it, and may not meet the requirements of high-precision paving operations.

[0110] To address this, this application further proposes a method for optimizing satellite positioning accuracy. Specifically, an antenna array is installed on top of the paving equipment. This antenna array consists of multiple satellite antennas with a preset first positional relationship and each capable of independently receiving signals from satellites. The antenna array is designed to provide a hardware foundation for high-precision satellite positioning. Through multiple independent receiving points, the system can acquire richer and more redundant satellite observation data, thereby improving the robustness and accuracy of positioning.

[0111] To ensure the quality of the satellite signals used, this method periodically determines the satellite performance parameters of candidate satellites. These parameters include at least one or more of the following: signal-to-noise ratio (SNR), Doppler shift, and pseudorange rate of change. Periodically determining these parameters allows for real-time evaluation of satellite signal quality and availability. SNR reflects the ratio of signal strength to noise level; a high SNR generally indicates good signal quality and low susceptibility to interference. Doppler shift is the signal frequency shift caused by the relative motion between the satellite and the receiver; its rate of change reflects the stability of the satellite's motion. The pseudorange rate of change reflects the rate of change of the distance between the satellite and the receiver. By periodically monitoring these parameters, the system can dynamically assess the signal quality of each candidate satellite, providing data support for subsequent satellite selection.

[0112] Subsequently, based on the determined satellite performance parameters, satellites affected by multipath interference are eliminated, thus obtaining the target satellites for positioning calculations. Multipath interference refers to the distortion and measurement errors caused by satellite signals being reflected by the ground, buildings, or other obstacles before reaching the receiver, resulting in superposition with the direct signal. By analyzing parameters such as signal-to-noise ratio, Doppler shift, and pseudorange change rate, satellite signals with abnormal quality, drastic fluctuations, or those inconsistent with the expected model can be identified; these anomalies are often manifestations of multipath effects. Eliminating these interfered satellites ensures that the signal source used for subsequent positioning calculations is of high quality, thereby improving the reliability of the positioning results.

[0113] Based on the signal transmission between the satellite antenna and the target satellite, the system obtains satellite signal reception information. This information includes pseudorange and carrier phase observations of the target satellite from each of the satellite antennas. The pseudorange observation is an approximate distance obtained by multiplying the time required for the satellite signal to travel from the satellite transmission point to the receiver by the speed of light; it typically contains various errors. The carrier phase observation, on the other hand, measures the carrier phase of the satellite signal, and its accuracy is far higher than that of the pseudorange observation, making it crucial for achieving centimeter-level or even millimeter-level positioning. By independently receiving and processing signals from the target satellite through each satellite antenna in the antenna array, multiple sets of pseudorange and carrier phase observations can be obtained. These data serve as the raw input for differential positioning and multipath error analysis.

[0114] Based on this, and using the carrier phase observations of each satellite antenna for the same group of target satellites, a second positional relationship between the satellite antennas is calculated using carrier phase differential technology. Carrier phase differential technology significantly improves the accuracy of relative positioning by eliminating or reducing common errors such as satellite clock bias, receiver clock bias, and atmospheric delay. When multiple satellite antennas simultaneously observe the same group of target satellites, the differences between their received carrier phase observations primarily reflect the relative positions of the antennas. By solving these phase differences, the relative geometric relationship between the individual satellite antennas in the antenna array, i.e., the second positional relationship, can be accurately determined. This is crucial for subsequent attitude calculation and multipath error estimation.

[0115] Furthermore, based on the geometric constraints of the paving equipment's mechanical structure, the first positional relationship, and the second positional relationship, the error caused by the multipath effect of each satellite antenna is estimated. The first positional relationship is a preset, ideal geometric configuration of the antenna array, while the second positional relationship is calculated based on actual carrier phase differential observations. Ideally, the two should be highly consistent. However, multipath effects can cause deviations in carrier phase observations, resulting in a difference between the calculated second positional relationship and the preset first positional relationship. By comparing these two and combining them with the known geometric constraints of the paving equipment's mechanical structure (e.g., the fixedness of the antenna installation position, equipment dimensions, etc.), the multipath error experienced by each satellite antenna can be deduced. This method utilizes the redundancy information and geometric constraints of the antenna array to improve the estimation accuracy of the multipath error.

[0116] Finally, when the estimated error caused by multipath effects exceeds a preset threshold, the system will re-select the target satellites and / or adjust the antenna parameters of the satellite antennas. If the error is too large, it indicates a potentially serious problem with the currently used satellite signal or antenna configuration. Re-selecting target satellites means abandoning those satellites that may be severely affected by multipath interference and selecting satellites with better signal quality for positioning. Adjusting the antenna parameters of the satellite antenna (e.g., antenna gain, beamwidth, phase center correction, etc.) can optimize the antenna's signal reception characteristics, thereby mitigating the impact of multipath effects. This dynamic adjustment mechanism allows the system to adapt to constantly changing operating environments and maintain high-precision positioning performance.

[0117] Through the above technical solution, this application can periodically evaluate the performance parameters of candidate satellites, thereby effectively eliminating satellites affected by multipath interference and ensuring that positioning calculations are based on high-quality target satellite signals. Furthermore, by accurately calculating the actual relative positions between each satellite antenna using carrier phase differential technology, and combining this with a preset first positional relationship and the geometric constraints of the equipment's mechanical structure, the error of each satellite antenna affected by multipath effects can be accurately estimated. When this error exceeds a preset threshold, the system can adaptively re-select target satellites or adjust satellite antenna parameters, thereby actively suppressing positioning errors caused by multipath effects. This significantly improves the accuracy and reliability of satellite positioning information, ensuring that the verified positioning information is more accurate. This, in turn, enables the controller to generate high-precision control parameters and timing-based control commands based on more accurate positioning information, ultimately improving the overall accuracy and stability of unmanned paving operations.

[0118] The above method proposes an unmanned paving control scheme based on a CAN bus in a controller area network. By setting multiple priorities for different message types and designing a corresponding CAN bus arbitration mechanism, it ensures the efficiency and reliability of communication within a single paving device. However, in multi-machine collaborative operation scenarios, especially when the paving device needs to interact closely with external equipment (such as a paving material mixer), the timely and reliable transmission of priority messages involving personnel safety and designated equipment safety is crucial.

[0119] In response, this application further proposes that when the paving equipment enters the designated range of the paving material mixer, the wireless communication module of the first paving equipment remains in an active state. When the wireless communication module receives a message of the first priority type, it wirelessly transmits it to the controller while maintaining the original timestamp of the message of the first priority type. When the paving equipment is outside the designated range, the wireless communication module switches between a sleep state and an active state periodically. The controller receives the message of the first priority type and the wirelessly transmitted message of the first priority type based on the CAN bus, and discards the message of successful reception based on the timestamp.

[0120] Specifically, when the paving equipment enters the designated area of ​​the paving material mixer, the wireless communication module is configured to remain in an active state. This means that the wireless communication module is always in a state where it can receive and transmit data, reducing the latency caused by waking the wireless communication module from a dormant state. In this state, once the wireless communication module receives a message of the first priority type, it immediately transmits it wirelessly to the controller. To ensure the real-time nature and accuracy of the message, the wireless communication module maintains the original timestamp of the first priority message during transmission. This is intended to ensure that the controller can accurately obtain the time information of the message's generation or first reception when processing the message, which is crucial for scenarios requiring strict timing control or event tracing, especially in critical message processing involving safety and collaborative operations.

[0121] When the paving equipment is outside the designated range, the wireless communication module is configured to periodically switch between a sleep state and an active state. This operating mode aims to optimize the equipment's energy management. In scenarios where the paving equipment is far from the paving material mixer, i.e., where high-frequency, high-real-time external communication is not required, the wireless communication module does not need to remain continuously active. By periodically entering a sleep state, the power consumption of the wireless communication module can be significantly reduced, thereby extending the overall battery life of the equipment. After the sleep cycle ends, the module briefly enters an active state to check for pending communication tasks, and then enters sleep again when there are no tasks, achieving a balance between power consumption and communication capability.

[0122] The controller is designed to receive both first-priority messages and wirelessly transmitted first-priority messages via the CAN bus. This means the controller has multi-channel message reception capabilities, allowing it to simultaneously monitor first-priority messages from both the internal CAN bus and external wireless communication modules. To avoid duplicate processing or logical conflicts caused by the same message being transmitted through different paths, the controller makes judgments based on the message's timestamp. Specifically, when the controller receives multiple copies of the same first-priority message, it compares the timestamps of these copies, discards the later-received messages, and only retains and processes the earliest received valid message. This mechanism ensures the uniqueness of message processing and the accuracy of timing, improving the system's response efficiency and reliability to critical information.

[0123] Through the above technical solution, this application effectively solves the problems of real-time and reliable transmission of first-priority messages and energy consumption management when paving equipment interacts with external equipment (such as a paving material mixer) in multi-machine collaborative unmanned paving operations. When the paving equipment enters the designated range of the paving material mixer, the wireless communication module remains active, ensuring that first-priority messages can be received immediately and wirelessly transmitted to the controller, and the original timestamp is retained. This greatly improves the real-time transmission of safety-related and multi-machine collaboration-related key information, avoiding potential safety hazards or collaborative synchronization failures caused by module wake-up delays. At the same time, when the paving equipment is outside the designated range, the wireless communication module periodically switches between sleep and active states, effectively reducing the overall energy consumption of the equipment, extending the operation time, and achieving a balance between energy consumption and communication performance. In addition, the controller effectively handles the problem of duplicate messages that may be generated due to multi-path transmission by discarding successfully received messages based on timestamps, ensuring the uniqueness and accuracy of message processing, avoiding misjudgments or duplicate operations caused by redundant information, thereby improving the safety and operating efficiency of the entire multi-machine collaborative unmanned paving system.

[0124] The following example will provide a more detailed explanation of the above technical solution: In a large-scale road construction project, multiple unmanned paving machines are working collaboratively. One of these machines is laying the asphalt pavement structural layer. This first paving machine integrates multiple functional components, including sensors, actuators, wireless communication modules, and controllers, all connected via a CAN bus. This integrated bus architecture effectively solves the problems of poor system scalability and numerous failure points caused by the dispersed placement of sensors, controllers, and actuators and the lack of unified bus scheduling in traditional paving equipment, laying the foundation for unmanned and intelligent operation.

[0125] Before paving operations begin, the controller assigns multiple priorities to different types of messages based on the current paving task (e.g., laying an asphalt concrete base layer). These priorities are divided into a first priority category and a second priority category. The first priority category is closely related to operational safety and the primary indicators of the paving task (such as structural indicators of the paved layer, including compaction degree and thickness uniformity), ensuring the priority transmission of critical safety information and structural quality parameters. The second priority category is related to paving operation control (such as non-structural indicators or equipment performance indicators like paving speed and screed temperature).

[0126] Specifically, the first priority category is further refined into: the highest priority category, used for messages related to personnel safety and equipment safety (e.g., emergency braking commands, obstacle collision warnings); the second highest priority category, used for messages related to multi-machine collaboration (e.g., speed synchronization commands with adjacent second paving equipment); and the lowest priority category, used for messages related to the first indicator of the current paving task (e.g., warnings of real-time paving thickness deviations).

[0127] The second priority category is further refined into: the highest priority category, used for messages related to the second indicator of the current paving task (e.g., non-structural indicators such as surface smoothness and temperature of the paved layer, or equipment performance indicators such as engine speed and hydraulic system pressure); the second highest priority category, used for messages related to equipment operating efficiency adjustment (e.g., adjustment of vibration frequency and screed heating power); and the lowest priority category, used for messages related to multi-machine collaborative assistance (e.g., updates to the location information of the material delivery vehicle). This refined priority division and management significantly improves the real-time performance and reliability of communication, overcoming the problems of high latency, poor anti-interference ability, and inability to meet the stringent requirements of unmanned operation caused by traditional communication methods.

[0128] Each message sent by a functional component contains a message identifier ID, which consists of a type ID followed by a serial number (SN). The type ID includes first-class bits and second-class bits, where the first-class bits are the high-order bits of the second-class bits. Different priorities correspond to different first-class bits, while different priority levels of the same type correspond to different second-class bits. The SN is used to distinguish different messages. Through this message ID structure, each functional component can quickly identify the type and priority of received messages, thereby enabling efficient scheduling and processing.

[0129] During paving operations, suppose a first component (e.g., a sensor module responsible for safety monitoring) detects an emergency ahead and needs to immediately send a first message of first priority (e.g., an emergency stop command). At this time, the CAN bus is being used by a second component (e.g., an actuator responsible for heating the ironing board), which is sending a second message of second priority (e.g., an ironing board heating power adjustment command). Upon detecting the CAN bus being occupied, the controller immediately determines whether the second message sent by the second component is of second priority. Since the second message is of second priority, the system immediately allows the first component to send its first message. The header of the first message contains a first sequence instructing the second component to pause the current transmission of the second message and buffer the received first message on the first channel. Simultaneously, the first message is buffered on the second channel by all received functional components, ensuring that emergency information is widely received. When the last message of the first communication is sent, it carries a second sequence at the end. This sequence instructs the second component to resume sending its second message within a first duration (e.g., 50 milliseconds), while the third component (e.g., an actuator responsible for paving speed control) does not participate in CAN bus contention within a second duration (e.g., 100 milliseconds) and resumes listening to the first message. The first duration being shorter than the second duration ensures rapid response to urgent messages while guaranteeing timely recovery of interrupted low-priority tasks, avoiding bus conflicts and data loss, and effectively solving the real-time performance limitations of traditional communication methods.

[0130] If the second message sent by the second component is also of the first priority (e.g., another security-related alert), then the first component will not immediately send its first message. Instead, it will wait for the second component to send its second message before competing for the CAN bus based on the first priority. This ensures that messages of equal importance are transmitted in an orderly manner, avoiding priority inversion or deadlock.

[0131] Similarly, if the first component has a third message of second priority (e.g., a paving speed adjustment command) to send, but the CAN bus is occupied by the second component, and the second component sends a second message of first priority, then the first component will wait for the second component to finish sending its second message before competing for the CAN bus based on first priority. This strategy ensures that high-priority messages are completed first, while also providing clear competition rules for subsequent low-priority messages.

[0132] After the wireless communication module detects a first-priority message on the CAN bus, it immediately transmits the same first-priority message wirelessly to the second paving equipment. For example, when the first paving equipment issues an emergency stop command, the second paving equipment can also receive this information synchronously and take corresponding measures, achieving real-time coordination and linkage between multiple machines. This solves the problems of traditional multi-machine lack of unified real-time communication, difficulty in maintaining consistency in paving thickness, speed, and overlap width, and the inability of a single machine to be independently controlled and linked with the material delivery vehicle and roller. It effectively avoids construction defects such as road surface steps, segregation, material breaks, overflow, under-compaction, and repeated paving.

[0133] The controller also utilizes an artificial intelligence (AI) module to determine control parameters based on sensor data of the paving material (e.g., temperature and gradation of the asphalt mixture), the initial working environment (e.g., ambient temperature and wind speed), and equipment operating status (e.g., engine load and hydraulic system pressure). These control parameters are used to regulate the operation of the paving equipment, such as adjusting the paving speed, screed heating temperature, and vibration frequency. This solves the problems of traditional equipment's inability to automatically switch and match process parameters, and its low versatility and intelligence.

[0134] To improve positioning accuracy, the system performs cross-verification of the work location based on satellite positioning information and local positioning information from the local wireless positioning module to obtain verified positioning information. For example, an antenna array is installed on the top of the first paving equipment. Multiple satellite antennas in this array have a first positional relationship and receive satellite signals independently. The system periodically determines the satellite performance parameters of candidate satellites, including signal-to-noise ratio, Doppler shift, pseudorange change rate, etc., and eliminates satellites affected by multipath interference based on these parameters to obtain the target satellites. Based on the signal transmission between the satellite antennas and the target satellites, satellite signal reception information is obtained, including pseudorange observations and carrier phase observations of each satellite antenna relative to the target satellite. Next, based on the carrier phase observations of each satellite antenna relative to the same group of target satellites, a second positional relationship between the satellite antennas is calculated using carrier phase differential. Finally, based on the geometric constraints of the paving equipment's mechanical structure, the first positional relationship, and the second positional relationship, the error caused by multipath effects of each satellite antenna is estimated. When the error exceeds a threshold, the system re-selects target satellites or adjusts the antenna parameters of the satellite antennas to ensure high-precision positioning.

[0135] Multiple local wireless positioning modules are distributed at different locations on the paving equipment. The system obtains local positioning information based on the positioning information of any two local wireless positioning modules and the distance between them. This multi-source positioning fusion and calibration mechanism significantly improves the positioning accuracy and reliability of unmanned paving operations, ensuring precise control of the paving trajectory and overlap width.

[0136] Based on the verified positioning information and control parameters, the controller generates time-sequential control commands and distributes these commands sequentially via the CAN bus to precisely control the various operations of the paving equipment. When the controller receives a message of the highest priority, it immediately generates an interrupt signal. Based on this interrupt signal, the processing of the time-sequential control commands is suspended, and the interrupt signal is processed first to ensure rapid response in emergency situations.

[0137] The controller also utilizes an AI module to calibrate parameters based on paving material information and secondary operating environment information (e.g., subgrade moisture and geological conditions). Based on these calibration parameters, it adjusts the sensor data acquisition parameters and determines the impact parameters of the operating environment indicated by the secondary operating environment information on the paving equipment's operational status. Finally, based on the calibrated acquisition parameters and impact parameters, it adjusts the operational control parameters. For example, it adjusts the compaction control parameters according to subgrade moisture to adapt to different construction conditions, further improving paving quality and equipment versatility.

[0138] For example, the second working environment information and the first working environment information are obtained in different ways. For instance, the first working environment information can be detected by sensors mounted on the paving equipment. The second working environment information can be received by the paving equipment from external devices. The working environment described by the second working environment information is more macroscopic than that described by the first working environment information. The second working environment information can be based on the current period of high rainfall, and combined with continuous rainfall, it can provide information such as overall environmental humidity and geological conditions.

[0139] When the paving equipment enters the designated area of ​​the paving material mixer, the wireless communication module remains active. At this time, upon receiving a first-priority message, the wireless communication module wirelessly transmits it to the controller while maintaining the original timestamp of the first-priority message. This ensures real-time, highly reliable communication with equipment such as material delivery vehicles in critical areas (such as near the material yard). Near the paving material mixer, the significant vibrations can affect CAN bus communication, leading to signal instability. Therefore, when the paving equipment is outside the designated area, the wireless transceiver module periodically switches between sleep and active states to save energy. The controller receives first-priority messages via the CAN bus and transmits them wirelessly, discarding successfully received messages based on their timestamps, avoiding redundant processing and data redundancy, further improving system reliability.

[0140] Through the above mechanism, the first paving equipment can achieve high-precision, high-reliability, and intelligent unmanned paving operations, and can coordinate with the second paving equipment and other auxiliary equipment in real time and efficiently, fundamentally solving various problems existing in traditional paving operations and significantly improving construction quality, efficiency and safety.

[0141] The following are some specific examples in conjunction with the above embodiments: Example 1: Dual-machine parallel unmanned paving operation The application scenario involves simultaneous dual-machine paving of wide road surfaces such as highways and airport runways, requiring smooth, stepless joints between the two road surfaces, and identical speed and thickness. The left-side controller and the right-side slave unit are simultaneously connected to the CAN bus. The controller periodically sends its own travel speed, paving thickness, overlap width, and real-time positioning information via the CAN bus, while the slave unit continuously listens for and parses the controller messages on the bus. Based on the controller messages, the slave unit automatically adjusts its own travel motor speed to keep the two machines synchronized, while simultaneously adjusting the thickness adjustment cylinder to maintain consistent paving thickness. It also corrects the lateral position based on the overlap width data, minimizing joint errors. The slave unit feeds back its actual speed, thickness, and position data to the controller via the CAN bus. The controller performs real-time fine-tuning based on the feedback values. When the deviation between the two machines exceeds a threshold, the controller forces correction via a high-priority CAN message, ensuring the continuity and smoothness of parallel paving.

[0142] Example 2: Automatic paving control for water-stabilized layer paving task The application scenario involves the paving of a water-stabilized layer, i.e., a cement-stabilized crushed stone base course. This layer is the main load-bearing structure of the road surface, requiring uniform thickness, high flatness, and stable paving speed. The system identifies the current work surface as a water-stabilized layer paving surface using BeiDou positioning and a preset construction layer. The controller automatically sends matching process parameters via the CAN bus, including a paving thickness of 18-20cm, a travel speed of 1.5-2.0m / min, and the rotation speed of the auger feeding mechanism. A thickness sensor detects the actual paving thickness in real time and uploads the data to the controller via the CAN bus. The controller calculates the deviation between the set thickness and the actual thickness, completing a closed-loop calculation every 50ms. When the deviation exceeds the allowable range (e.g., ±1cm), the controller outputs a control signal via the CAN bus to drive the thickness adjustment mechanism. If the thickness is too high, the scraper is lowered; if the thickness is too low, the scraper is raised, ensuring the water-stabilized layer thickness remains within the design tolerance range.

[0143] Example 3: Coordinated control of paver and material delivery vehicle The application scenario is continuous asphalt or water-stabilized paving operations, requiring uninterrupted material supply to prevent downtime due to material shortages or waste from spillage. The paver's material level sensor monitors the material height in the hopper in real time and broadcasts the material level status data to the bus via CAN bus. When the material level is below 30%, a low-level emergency message is sent. Upon receiving the low-level message via CAN bus, the material delivery vehicle automatically approaches the paver at low speed and activates the unloading mechanism according to the matched speed, maintaining continuous material replenishment. When the paver's material level rises above 80%, the controller sends a full-material stop command via CAN bus. Upon receiving the message, the material delivery vehicle immediately stops unloading and slowly retreats to a safe distance to wait, achieving unmanned material supply coordination.

[0144] Example 4: Linkage control between paver and roller The application scenario is asphalt pavement paving, where asphalt needs to be compacted within a high-temperature range; a rapid temperature drop would affect the compaction quality of the pavement. After completing each paving section, the paver immediately broadcasts the completed section, pavement temperature, and current location information via the CAN bus. Upon receiving the CAN message, the roller automatically enters the corresponding paving section and begins compaction according to the preset process, simultaneously feeding back the compaction status via the CAN bus. Based on the roller's operating position and progress, the paver maintains a safe working distance and continues paving forward. After completing compaction, the roller sends a completion signal via the CAN bus. Upon receiving the signal, the paver continues to advance at full speed, achieving continuous unmanned operation of paving and compaction simultaneously.

[0145] Example 5: Optimized Scraper Adjustment via CAN Bus in a Single Paver System: In a single paver system, the travel motor speed sensor sends the current paving speed (e.g., 2.0 m / min) in the first cycle, and the thickness sensor (CANID0x102) feeds back the real-time paving thickness (e.g., 18.2 cm) in the second cycle. The controller (PLC) receives this data in real time via the CAN bus. When it detects that the current thickness deviates from the target value (e.g., the water-stabilized layer requires 18 ± 0.3 cm, but is actually 18.5 cm), it immediately sends an adjustment command (e.g., "scraper rise 2 mm") via CANID0x201 (scraper adjustment cylinder control). The cylinder actuator responds, scraping back the excess paving material. The delay of the entire control closed loop is small. The second cycle is shorter than the first cycle.

[0146] Example 5: Wireless collaboration between devices enables automatic material replenishment: When the laser level sensor (detection range 0-100%, accuracy ±2%) in the paver's hopper detects that the material level is below 30% (e.g., currently at 25%) via the CAN bus, the controller no longer notifies the delivery vehicle via a long CAN cable (traditional solutions may result in signal loss due to excessive cable length). Instead, it sends a "low material level request" message (message type 0x10, parameter "replenishment rate required 1.5m") to the nearest delivery vehicle (device ID: 002) via a Wi-Fi 6 wireless link (coverage radius ≥100 meters, bandwidth ≥100Mbps). 3After receiving the material, the delivery vehicle calculates the optimal driving path using its own material level sensor and positioning system (e.g., approaching the paver at a low speed of 0.5 m / s), and replies via wireless link with "Estimated arrival time 25 seconds, unloading speed adjusted to 200 rpm". When the paver's material level rises to 80%, it sends a "stop unloading" command wirelessly again, and the delivery vehicle immediately shuts off the unloading mechanism and retreats to a safe distance (e.g., 5 meters away). The entire collaborative process requires no manual intervention and avoids the complex wiring problems caused by CAN bus connections across devices in traditional solutions (e.g., when multiple delivery vehicles are operating simultaneously, if a CAN bus is used, each vehicle needs to pull a long cable to the paver, which is very easy to get tangled and damaged).

[0147] Example 6: Dual-link redundancy guarantee for emergency stop: When the lidar in front of the paver (detection range 0-5 meters, accuracy ±0.1 meters) detects personnel entering the safe area (e.g., less than 2 meters from the paver's auger feeder) via the CAN bus, the controller first sends a "full machine emergency stop" command via the CAN bus (ID0xFF, highest priority) (requiring the travel motor to power off, the auger feeder to stop, and the scraper to lock). However, if the CAN bus experiences poor cable contact due to vibration (in simulation experiments, when the vibration intensity is >5g, the CAN line error rate can reach over 5%), the controller will automatically switch to the Wi-Fi 6 wireless link within 5ms and broadcast an "emergency stop" message (message type 0xFF, parameter "immediate stop") to all associated devices (paver, feeder, roller). After receiving the material, the delivery vehicle stops unloading and brakes; after receiving the material, the road roller pauses compaction and reverses. The entire emergency response time is shortened from 10-15ms on a single CAN bus to 20ms in the worst case (wireless relay after CAN failure), which is faster than the industry standard (response within 30ms) and effectively avoids personnel casualties or equipment collision accidents.

[0148] This layered hybrid communication architecture retains the advantages of CAN bus in high real-time control within a single machine, while using wireless communication to solve the flexibility problem of long-distance collaboration among multiple devices. At the same time, it improves the reliability of critical scenarios through redundant design, making it more suitable for complex and ever-changing road construction environments than traditional pure CAN solutions.

[0149] First, a 24GHz millimeter-wave wireless redundant channel is superimposed on the traditional single-wire CAN bus to form a "wired + wireless" dual-link system. Key control commands (such as emergency braking and emergency stop) are simultaneously transmitted via the CAN bus and the millimeter-wave wireless link. The receiving end confirms validity through timestamp comparison and a voting mechanism, while ordinary status data (such as periodic sensor sampling values) only travels via the CAN bus to reduce power consumption. Second, a lightweight neural network (based on an edge computing model using the TinyML framework) is integrated to collect historical coupled data on material type, ambient temperature and humidity, equipment operating status, and paving thickness in real time. This dynamically generates optimal process parameters and automatically writes them into the CAN message configuration block, replacing manually preset fixed parameter tables. Finally, a UWB anchor point (such as the Decawave DWM1000 module) is added to each device. Time-of-flight (TOF) ranging is used to calculate the actual distance between adjacent devices (accuracy ±3mm), compensating for the meter-level error of BeiDou positioning. UWB data is transmitted through an independent CANID segment for cross-verification with the main positioning system, solving the relative position drift problem when multiple devices operate in parallel. Example 7: Vibration-resistant millimeter-wave wireless redundancy emergency stop When a paver operates near a concrete mixing plant, the machine vibrates at a rate of 4g and experiences strong electromagnetic interference (50Hz harmonics generated by the mixer truck's motor). If an "emergency stop" command is sent via a single-wire CAN bus (e.g., if personnel are detected entering a safe area), the vibration could loosen the CAN connector, increasing the error rate to over 3% and posing a significant risk of command loss. This solution transmits the "emergency stop" command simultaneously through two paths: one via the CAN bus (ID0xFF, highest priority), and the other via a millimeter-wave wireless module (silicone potting + vibration-damping bracket fixation, vibration resistance up to 10g) of a five-wireless communication module. Upon receiving the command, the receiving end (such as the paver, feeder truck, or roller) ensures command reliability through timestamp comparison (the time difference between the CAN bus and the wireless signal transmission must be <1ms) and a voting mechanism (only commands received on both paths are executed; if only received on one path, a secondary confirmation is triggered). Actual test data shows that in a 4G vibration environment, the efficiency of the emergency stop command of this solution has increased from 92% to 99.8% with a single CAN bus, and normal status data (such as thickness sensor reporting once every 10ms) still only goes through the CAN bus, avoiding the high power consumption of the wireless link from affecting battery life.

[0150] Example 8: AI self-learning to match dynamic parameters of water-stable layer During the paving of a water-stabilized layer in a certain project, continuous rain caused the moisture content of the base layer to rise from the usual 8% to 12%. If the traditional fixed parameters (paving speed 1.8m / min, auger speed 25rpm, target thickness 18-20cm) were used, the actual value reported by the thickness sensor was as high as 21-22cm (error exceeding 2cm). The controller of this solution integrates TinyML lightweight neural network (the model parameters are only 50KB, and it can be inferred in real time on the ARM Cortex-M7 chip). It has been pre-learned from historical data: when the material is cement-stabilized crushed stone, the ambient humidity is >90%, and the base layer moisture content is >10%, the optimal parameter combination is "speed 1.5m / min, auger speed 20rpm, scraper height +1cm (to compensate for the decrease in compaction)". During construction, sensors collect real-time data on current humidity (12%), material type (water-stabilized crushed stone), and auger feeding current (reflecting density resistance). The neural network outputs adjustment suggestions within 50ms (speed reduced to 1.6m / min, auger speed reduced to 22rpm) and automatically writes them into the CAN message configuration block (ID0x205), driving the actuator to dynamically adjust. The final paving thickness error is controlled within ±0.5cm, a 60% improvement over traditional fixed-parameter solutions. Furthermore, the model iterates online with each construction data iteration (optimized via cloud transmission through a 5G private network), adapting to the material characteristics of different regions.

[0151] Example 9: UWB compensation for misalignment in BeiDou positioning seams When paving a 6-meter-wide road surface in parallel with two pavers, the lateral distance between the two pavers (left controller and right slave) must be strictly controlled within 30cm ± 1cm, and the height of the joint step must be ≤ 1cm. If relying solely on BeiDou positioning (civilian accuracy ±0.8m), due to multipath effects (such as signals reflected by metal manhole covers below the paver), the slave paver may deviate from the controller by 5-8mm, resulting in obvious steps at the joint. In this solution, each paver is equipped with 3 UWB anchor points (located at the front, middle, and rear of the machine body, respectively). The actual distance between adjacent anchor points is calculated using TOF ranging (for example, the real-time distance between the middle anchor point of the left controller and the middle anchor point of the right slave paver is 30.02cm, with an error of only ±2mm). When Beidou positioning indicates a lateral distance of 30cm between the two units (though actual deviations may occur due to signal drift), UWB data is transmitted to the controller via an independent CANID segment (e.g., 0x300-0x3FF). After cross-verification with Beidou data, the controller calculates a correction (e.g., "the slave unit needs to be slightly adjusted to the left by 0.8mm") and sends an adjustment command (ID0x203, controlling the PWM duty cycle of the slave unit's walking motor) via the CAN bus. Actual measurements show that this solution can reduce the step height at the joint between the two units from the traditional 1.5-2mm to 0.3-0.5mm, fully meeting the acceptance standards for high-grade highways (≤1cm). Furthermore, the UWB module synchronously calibrates the timestamp via the CAN bus, avoiding the accumulation of ranging errors caused by clock asynchrony among multiple units.

[0152] This composite solution breaks through the reliability bottleneck of traditional paving systems in complex environments through three layers of innovation: "vibration-resistant communication guarantee + AI parameter adaptation + sub-centimeter positioning collaboration". At the same time, it realizes intelligent process and precise collaboration, and significantly improves the overall construction quality compared with single technology improvement (thickness error <0.3cm, joint misalignment <0.5mm, emergency stop response <10ms), making it more suitable for the unmanned construction needs of high-grade roads.

[0153] In some embodiments, such as Figure 3 As shown, this disclosure provides a multi-machine collaborative unmanned paving control system based on a CAN bus of a controller area network, executed by a first paving device. The first paving device includes multiple functional components connected by a CAN bus. The multiple functional components include a first component, a second component, and a third component. The multiple functional components specifically include sensors, actuators, wireless communication modules, and controllers.

[0154] The system includes: The setting module 1110 is used to set multiple priorities for different types of messages according to the paving task currently being performed by the paving equipment; the multiple priorities include a first priority and a second priority; the first priority is related to safety and the first indicator of the paving task; the second priority is related to paving operation control. The determination module 1120 is used to determine whether the second message sent by the second component is of the second priority when the first component sends a first message of the first priority and the CAN bus is detected to be occupied by the second component. The sending module 1130 is configured to preempt the CAN bus to send the first message when the second message has the second priority level; the header of the first message includes a first sequence; the first sequence is used to instruct the second component to pause the transmission of the second message, and is used by each functional component to buffer the received second message in the first channel; the first message is buffered by each of the functional components in the second channel; the tail of the last message carries a second sequence; the second sequence is used to instruct the second component to resume the transmission of the second message within a first duration, and the third component does not participate in the CAN bus occupation contention and resumes listening to the first message within the second duration; the first duration is shorter than the second duration; The waiting module 1140 is used to wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority when the second message is of the first priority; and to wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority when the first component has a third message of the second priority and detects that the CAN bus is occupied by the second component. The transmitting module 1130 is further configured to wirelessly transmit the first priority message to the second paving device after the wireless communication module listens for the first priority message on the CAN bus.

[0155] Combination Figure 4 As shown, this application provides an electronic device that can be a component of a satellite-based photovoltaic piling guidance system, including a processor 10 and a memory 11. Optionally, the device may further include a communication interface 12 and a bus 9. The processor 10, communication interface 12, and memory 11 can communicate with each other via the bus 9. The communication interface 12 can be used for information transmission. The processor 10 can call logical instructions in the memory 11 to execute the CAN bus-based multi-machine cooperative unmanned paving control method described in the above embodiment.

[0156] Furthermore, the logical instructions in the aforementioned memory 11 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0157] The memory 11, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of this application. The processor 10 executes functional applications and data processing by running the program instructions / modules stored in the memory 11, thereby realizing the multi-machine cooperative unmanned paving control method based on the CAN bus in the above embodiments.

[0158] The memory 11 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the electronic device. Furthermore, the memory 11 may include high-speed random access memory and may also include non-volatile memory.

[0159] The embodiments or examples disclosed in this application are not exhaustive, but merely illustrative of some embodiments or examples, and are not intended to limit the scope of protection of this disclosure. Unless contradictory, each step in a particular embodiment or example can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a particular embodiment or example can also be implemented as an independent embodiment, and the order of the steps in a particular embodiment or example can be arbitrarily interchanged. Furthermore, optional methods or examples in a particular embodiment or example can be arbitrarily combined; moreover, embodiments or examples can be arbitrarily combined. For example, some or all steps of different embodiments or examples can be arbitrarily combined, and a particular embodiment or example can be arbitrarily combined with optional methods or examples of other embodiments or examples.

[0160] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0161] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0162] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0163] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0164] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for unmanned paving control of multiple machines based on a controller area network (CAN) bus, characterized in that, The method is performed by a first paving device, which includes multiple functional components connected via a CAN bus; the multiple functional components include a first component, a second component, and a third component; the method includes: Based on the paving task currently being performed by the paving equipment, multiple priorities are set for different types of messages; the multiple priorities include a first priority and a second priority; the first priority is related to safety and a first indicator of the paving task; the second priority is related to paving operation control; the first indicator includes the structural indicators of the paving layer of the currently performed paving task; When the first component sends a first message of the first priority and detects that the CAN bus is occupied by the second component, determine whether the second message sent by the second component is of the second priority. When the second message is of the second priority type, the third component preempts the CAN bus to send the first message; the header of the first message includes a first sequence; the first sequence is used to instruct the second component to pause the transmission of the second message, and is used by each functional component to buffer the received second message in the first channel; the first message is buffered by each of the functional components in the second channel; the tail of the last message carries a second sequence; the second sequence is used to instruct the second component to resume the transmission of the second message within a first duration, and the third component does not participate in the CAN bus occupation contention and resumes listening to the first message within the second duration; the first duration is less than the second duration; When the second message is of the first priority, wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority. When the first component sends a third message with a second priority and detects that the CAN bus is occupied by the second component, it waits for the second component to finish sending the second message and then competes for the CAN bus based on the second priority. After detecting a message of the first priority type on the CAN bus, the message of the first priority type is wirelessly transmitted to the second paving device.

2. The method of claim 1, wherein, The step of setting multiple priorities for different types of messages based on the paving task currently being performed by the paving equipment includes: The system sets a first priority category and a second priority category. The first priority category includes at least: a first highest priority category for messages related to personnel safety and equipment safety; a first second highest priority category for messages related to multi-machine collaboration; and a first lowest priority category for messages related to a first indicator of the currently performed paving task. The first indicator includes structural indicators related to the paving layer of the currently performed paving task. The second priority category includes: a second highest priority category for messages related to a second indicator of the currently performed paving task. The second indicator is a non-structural indicator of the paving layer of the currently performed paving task and / or a performance indicator related to the equipment; a second second highest priority category for messages related to equipment operating efficiency adjustment; and a second lowest priority category for messages related to multi-machine collaborative assistance. Based on the equipment status monitoring information of the paving equipment, determine whether the status of the non-designated safety-related components of the paving equipment is abnormal; When the state of the non-designated security associated component is abnormal, the priority of non-device-designated security-related messages is increased from the second priority category to the first priority category.

3. The method of claim 1, wherein, The CAN bus preemption mechanism includes an application layer preemption mechanism and / or a hardware layer preemption mechanism; the method further includes: When the application layer preemption mechanism is executed, the application layer of the first component sends a first application layer message to the CAN controller of the first component; wherein the first application layer message contains the first message; the CAN controller of the first component encapsulates the first application layer message into a first CAN frame and transmits it on the CAN bus; after receiving the first CAN frame, the CAN controller of the second component decapsulates the first CAN frame into a second application layer message and sends the second application layer message to the application layer of the second component; the application layer of the second component triggers an interrupt based on the second application layer message to pause the transmission of the second message and save the context information; the context information is used to resume the transmission of the second message; after receiving the first CAN frame, the CAN controller of the third component decapsulates the first CAN frame into a third application layer message and sends it to the application layer of the third component; the application layer of the third component marks the CAN bus as a preset time period based on the third application layer message and the second duration, so as not to participate in CAN bus contention within the preset time period; When the hardware layer preemption mechanism is executed, the CAN controller of the first component sends a second CAN frame through the CAN bus during the inter-frame gap of the CAN bus; wherein, the second CAN frame is generated based on the first message of the first component; after receiving the second CAN frame, the CAN controller of the second component suspends the transmission of the second priority message of the current second component and caches the breakpoint information in the hardware buffer, the breakpoint information is used to resume the transmission of the second priority message; after receiving the second CAN frame, the CAN FD controller of the third component shields the CAN bus contention and maintains a listening state for a preset period based on the second duration.

4. The method according to claim 3, characterized in that, According to the preemption execution rate, the preemption mechanism includes: A progressive preemption mechanism is used to allow the second component to actively release the CAN bus after completing the transmission of a specified data segment within a limited time by sending a warning frame carrying a delayable transmission duration to the second component. An immediate preemption mechanism is used to immediately terminate the second message transmission of the second component and occupy the CAN bus by immediately executing the hardware layer preemption mechanism or the application layer preemption mechanism. Specifically, the gradual preemption mechanism is activated under normal operating conditions, and the immediate preemption mechanism is switched to under critical operating conditions. The critical operating conditions are those in which an event related to personnel safety and specified equipment safety occurs when the remaining time of the paving time window is less than a critical threshold. The normal operating conditions are those other than the critical operating conditions. The paving time window is generated based on the characteristics of the paving material and the paving requirements.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: The controller determines control parameters based on information collected by sensors from paving materials, the first working environment, and the equipment operating status using an artificial intelligence (AI) module; these control parameters are used to control the operation of the paving equipment. The work location is cross-verified based on satellite positioning information and local positioning information from local wireless positioning modules to obtain verified positioning information; wherein, there are multiple local wireless positioning modules distributed at different locations of the paving equipment; the local positioning information is obtained based on the positioning information of any two local wireless positioning modules and the distance between the two local wireless positioning modules. Based on the verified positioning information and the control parameters, a time-sequential control command is generated. The timing-sequential control commands are distributed via the CAN bus in sequence. When the controller receives a message of the first priority type, it generates an interrupt signal, suspends the processing of the timing control instructions based on the interrupt signal, and processes the interrupt signal first.

6. The method according to claim 4, characterized in that, An antenna array is installed on the top of the paving equipment body; The antenna array consists of multiple satellite antennas; the satellite antennas have a first positional relationship and each independently receives satellite signals; the method further includes: Periodically determine the satellite performance parameters of the candidate satellites; the satellite performance parameters include at least one of the following: signal-to-noise ratio, Doppler frequency shift, pseudorange rate of change; Based on the satellite performance parameters, satellites affected by multipath interference are eliminated to obtain the target satellite; Based on the signal transmission between the satellite antenna and the target satellite, satellite signal reception information is obtained; the satellite signal reception information includes pseudorange observations and carrier phase observations of each of the satellite antennas to the target satellite; Based on the carrier phase observations of each of the satellite antennas for the same group of target satellites, the second positional relationship between each of the satellite antennas is calculated using carrier phase differential. Based on the geometric constraints of the paving equipment's mechanical structure, the first positional relationship, and the second positional relationship, the error caused by the multipath effect of each of the satellite antennas is estimated; When the error exceeds the threshold, the target satellite is re-screened and / or the antenna parameters of the satellite antenna are adjusted.

7. The method according to any one of claims 1 to 3, characterized in that, The method further includes: When the paving equipment enters the designated range of the paving material mixer, the wireless communication module of the first paving equipment remains active. When the wireless communication module receives a message of the first priority, it wirelessly transmits it to the controller while maintaining the original timestamp of the message of the first priority. When the paving equipment is outside the designated range, the wireless communication module switches between a sleep state and an active state periodically. The controller receives messages of the first priority type and wirelessly transmitted messages of the first priority type based on the CAN bus, and discards the messages based on the timestamps and then receives the messages successfully.

8. The method according to any one of claims 1 to 3, characterized in that; The method further includes: When the CAN bus preemption mechanism is activated, the transmission of messages of the first priority is allowed to preempt the transmission of messages of the second priority from occupying the CAN bus. When the preemption mechanism is deactivated, the transmission of messages of the first priority is prohibited from preempting the transmission of messages of the second priority from occupying the CAN bus.

9. A multi-machine cooperative unmanned paving control system based on a CAN bus in a controller area network, characterized in that, Performed by a first paving device, the first paving device comprising multiple functional components connected via a CAN bus; the multiple functional components including a first component, a second component, and a third component; the system comprising: The setting module is used to set multiple priorities for different types of messages based on the paving task currently being performed by the paving equipment. The multiple priorities include a first priority and a second priority. The first priority is related to safety and a first indicator of the paving task. The second priority is related to paving operation control. The first indicator includes the structural indicators of the paving layer of the paving task currently being performed. The determination module is used to determine whether the second message sent by the second component is of the second priority when the first component sends a first message of the first priority and the CAN bus is detected to be occupied by the second component. A sending module is configured to preempt the CAN bus to send the first message when the second message has the second priority level; the header of the first message includes a first sequence; the first sequence is used to instruct the second component to pause the transmission of the second message, and is also used by each functional component to buffer the received second message in the first channel; the first message is buffered by each of the functional components in the second channel; the tail of the last message carries a second sequence; the second sequence is used to instruct the second component to resume the transmission of the second message within a first duration, and the third component does not participate in the CAN bus occupation contention and resumes listening to the first message within the second duration; the first duration is shorter than the second duration; The waiting module is configured to wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority when the second message is of the first priority; and to wait for the second component to finish sending the second message and then compete for the CAN bus based on the second priority when the first component has a third message of the second priority and detects that the CAN bus is occupied by the second component. The transmitting module is further configured to wirelessly transmit the message of the first priority type to the second paving device after listening to the message of the first priority type on the CAN bus.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions; when executed by a processor, the computer-executable instructions are able to implement the method described in any one of claims 1 to 7.

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