A distributed ranging scheduling method based on UWB

Abstract

This invention relates to the field of wireless communication and ranging technology, specifically a distributed ranging scheduling method based on UWB, comprising the following steps: S1, preset rules; S2, self-organizing network: autonomously determining its own group and ranging time sequence to form a distributed ranging network; S3, ordered ranging: all devices take turns as senders according to the ranging time sequence, broadcasting ranging packets; the remaining devices act as receivers to receive the ranging packets and calculate the distance value; during ordered ranging, if a receiver does not receive the ranging packet from the corresponding sender in the expected time sequence, a preset time delay is initiated, and if the packet is still not received after the timeout, it automatically jumps to the next sequence number sender to continue execution; this invention eliminates the risk of single-point failure, improves the ranging range, eliminates the dependence on high-precision clock synchronization, and reduces deployment complexity and hardware costs, and can be widely applied to scenarios requiring multi-device distributed ranging, such as UAV swarm formation, factory collision avoidance warning, and emergency search and rescue.

Description

Technical Field

[0001] This invention relates to the field of wireless communication and ranging technology, specifically to a distributed ranging scheduling method based on UWB. Background Technology

[0002] Ultra-wideband (UWB) technology, with its advantages of strong resistance to multipath interference, high ranging accuracy, and high transmission speed, has been widely used in indoor positioning, device ranging, and target tracking. In current conventional UWB positioning or ranging applications, most solutions rely on determining a central node in the positioning system or manually setting up the network topology before they can operate. When the positioning base station is fixed, this solution is effective and stable.

[0003] With the promotion and development of UWB technology, more application scenarios for ranging between non-fixed devices are emerging, such as drone swarm flight, collision avoidance warnings between forklifts and personnel in factories, and emergency search and rescue missions like firefighting. These applications are characterized by multi-device ranging, no fixed roles, and variable positional relationships. To meet these needs, UWB distributed ranging solutions have emerged, enabling various UWB nodes to measure distances with each other.

[0004] In current mainstream distributed ranging solutions, a centralized TDMA scheduling scheme is generally adopted. This involves pre-designating a master device from multiple ranging devices, with the others acting as slave devices. The master device manages the ranging time slices of the slave devices to control the entire ranging process. While this scheme is simple and relatively reliable, it has the following problems: First, single point of failure risk: if the master device fails, the entire ranging network will be paralyzed, and the ranging function will be unusable. Second, limited ranging range: the ranging range is limited to the radio frequency range of the master device, making it unsuitable for wider ranging applications. Third, reliance on global clock synchronization leads to high deployment complexity and hardware costs, and it cannot adapt to scenarios where devices dynamically join and leave. Summary of the Invention

[0005] The purpose of this invention is to provide a distributed ranging scheduling method based on UWB, which aims to improve the problems of existing distributed ranging schemes, such as dependence on a central node, susceptibility to system paralysis due to main device failure, limited ranging range, dependence on clock synchronization, and complex deployment.

[0006] This invention is implemented as follows: A distributed ranging scheduling method based on UWB includes the following steps: S1. Preset rules: Determine the unique identifier for each UWB ranging device, and preset the identifier sorting rules and device grouping rules; S2, self-organizing network: Each device broadcasts its own identifier and listens to the broadcasts of other devices. Based on the received identifier information, it constructs an ordered local device list and autonomously determines its own group and ranging time sequence based on the ordered list and preset grouping rules, thus forming a distributed ranging network. S3. Ordered ranging: All devices take turns as the sender according to the ranging sequence, broadcasting ranging packets; the remaining devices receive the ranging packets and calculate the distance value; the ranging process is executed in a phased sequence centered on each group. During the ordered ranging process, if the receiver does not receive the ranging packet from the corresponding sender in the expected sequence, a preset delay time is initiated. If the packet is still not received after the timeout, the process automatically jumps to the next sender in the sequence number to continue execution, ensuring that the ranging process is continuous and uninterrupted.

[0007] Furthermore, the unique identifier is a short ID with consecutive numbers, and the identifier sorting rule is to arrange them in ascending or descending order of short ID value. The ranging sequence is consistent with the identifier sorting order.

[0008] Besides short IDs with consecutive numbers, unique identifiers can also be MAC addresses, SN serial numbers, custom unique identifiers (UIDs), and other identifiers that are unique and can be ordered, as long as they can distinguish different devices and determine the sending order.

[0009] Furthermore, the device grouping rule is as follows: the devices in the ordered local device list are divided into N groups according to their sorting position, where N is an integer greater than or equal to 1.

[0010] Furthermore, the number of devices in each group does not exceed a preset maximum value, and the number of devices in any group is at least 2.

[0011] Furthermore, the phased time sequence centered on each group specifically includes: The first phase, centered on the first group, involves sequentially completing the mutual distance measurement between devices within the group, as well as the distance measurement between devices from other groups and the devices in that group. The second phase, centered on the second group, involves sequentially measuring the distance between the devices in other groups and the devices within that group, as well as measuring the distance between each other within the same group. This process continues until all groups have completed the distance measurement in turn, serving as the center in turn. After the current ranging cycle ends, it will automatically return to the starting point of the first stage and begin the next ranging cycle.

[0012] Furthermore, each stage specifically includes: First sub-phase: Other group devices take turns acting as transmitters to measure the distance to the central group's devices in this phase; Second sub-phase: In this phase, the devices within the central group act as transmitters in turn, measuring distances to other devices within the group. Third sub-phase: The remaining devices in other groups take turns as transmitters to measure the distance to the devices in the central group of this phase.

[0013] Furthermore, the preset duration is greater than or equal to the time required for a single device to complete one ranging packet transmission.

[0014] Furthermore, the duration of the self-organizing network step is a preset time period during which the devices continuously broadcast and listen to ensure that a complete and ordered list of local devices is obtained through convergence.

[0015] Furthermore, the ranging packet is sent in a broadcast manner to achieve one-to-many ranging with multiple receivers receiving a single transmission; the calculated distance value is only recorded and stored by the receiver, and the sender does not store the distance value of this ranging measurement.

[0016] Furthermore, in the self-organizing network step, the devices alternately broadcast and listen in an intermittent manner; after the self-organizing network ends, each device determines its own group according to its unique identifier in the ordered local device list and the device grouping rules, and determines its own transmission order in the ranging timing according to the identifier sorting rules.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention forms a distributed UWB ranging solution that does not require a central node, does not rely on clock synchronization, and is easy to deploy by organically combining dynamic self-organizing network, strict timing scheduling, grouped and phased ranging, and anomaly handling. It eliminates the risk of single-point failure, improves the ranging range, gets rid of the dependence on high-precision clock synchronization, and reduces deployment complexity and hardware costs. It can be widely used in scenarios that require distributed ranging of multiple devices, such as UAV swarm formation, factory collision avoidance warning, and emergency search and rescue. Attached Figure Description

[0018] Figure 1 This is a flowchart of the distributed ranging and scheduling method based on UWB provided by the present invention. Detailed Implementation

[0019] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details: Example 1

[0020] This embodiment provides a distributed ranging scheduling method based on UWB, such as... Figure 1 As shown, it includes the following steps: S1. Preset rules: Determine the unique identifier of each UWB ranging device, and preset the identifier sorting rules and device grouping rules.

[0021] Specifically, in this embodiment, the unique identifier is a short ID with consecutive numbers, ranging from 0 to 51, and the total device capacity does not exceed 52 units. The identifier sorting rule is to arrange them in ascending order of short ID value. The device grouping rule is as follows: after sorting the devices by short ID from smallest to largest, they are divided into four groups: Group A (ID0~12), Group B (ID13~25), Group C (ID26~38), and Group D (ID39~51).

[0022] Besides short IDs with consecutive numbers, unique identifiers can also be MAC addresses, SN serial numbers, custom unique identifiers (UIDs), and other identifiers that are unique and can be ordered, as long as they can distinguish different devices and determine the sending order.

[0023] S2. Self-organizing network: Each device broadcasts its own identifier and listens to the broadcasts of other devices. Based on the received identifier information, it constructs an ordered local device list and autonomously determines its own group and ranging time sequence based on the ordered list and preset grouping rules, thus forming a distributed ranging network.

[0024] Specifically, in this embodiment, before ranging begins, all devices are forced into ad-hoc network mode for 15 seconds. Devices intermittently send UWB broadcast packets, each carrying its own short ID; immediately after sending, they switch to listening mode to receive broadcast packets from neighboring devices. Each device extracts the short IDs from all received broadcast packets and sorts them in ascending order to generate a local device list. After ad-hoc network operation ends, each device determines its group based on its short ID's position in the device list (e.g., if the position is 0-12, it belongs to group A, and so on), and determines its sending order in the ranging timing according to the ascending order of its short ID.

[0025] S3. Ordered ranging: All devices take turns as the sender according to the ranging sequence and broadcast the ranging packet; the remaining devices receive the ranging packet and calculate the distance value; the ranging process is executed in a phased sequence centered on each group.

[0026] Specifically, in this embodiment, the ranging adopts a "one-to-many" mode, that is, a single transmission and multiple receivers, with only the receiver recording the ranging value. The entire process is divided into four stages according to groups, with ranging performed sequentially around groups A, B, C, and D. Within each stage, the process follows the order of "other groups measuring the distance to this group → distance measurement within this group → distance measurement by the remaining other groups to this group". After the current ranging cycle ends, it automatically resets and begins the next cycle.

[0027] Anomaly Handling: During the ordered ranging process, if the receiver does not receive the ranging packet from the corresponding sender in the expected sequence, a preset delay time will be started to wait. If the packet is still not received after the timeout, the receiver will automatically jump to the next sender in the sequence number to continue execution, ensuring that the ranging process is continuous and uninterrupted.

[0028] Specifically, in this embodiment, if device Y is supposed to receive a ranging packet from device Q but does not receive it within the expected time, Y actively extends the receiving window by 15 milliseconds and continues to wait for Q's packet. If Q's packet is still not received within 15 milliseconds, Y abandons waiting for Q and starts waiting for the packet from device Q+1, continuing to process subsequent packet-sending devices according to this rule. If Q=51, the next ranging cycle begins. This mechanism effectively avoids the entire ranging process being interrupted due to a single device failure or signal interference.

[0029] Example 2: Self-organizing network and ranging process from a single device's perspective: This embodiment follows the grouping rules of Embodiment 1, taking the device with short ID 5 (belonging to Group A) as an example to describe the complete ranging process from a single device's perspective.

[0030] I. Equipment Grouping and Identification There are a total of 52 devices. The short ID allocation range is 0 to 51. The grouping rule is: sorted by short ID from smallest to largest and divided into four groups: Group A: ID 0 to 12; Group B: ID 13 to 25; Group C: ID 26 to 38; Group D: ID 39 to 51.

[0031] II. Self-organizing network stage: Device 5 broadcasts its own ID (5) for 15 seconds while simultaneously listening for air signals. When the self-organizing network ends, it extracts a device list from the received broadcast packets, assuming there are all devices with IDs 0, 1, 2, 3, 4, 5, 6...51 in the network. After generating its local device list, device 5 determines its own position in the list (6th position, counting from 0) and accordingly identifies itself as belonging to group A.

[0032] III. Distance Measurement Phase: Phase ① (Focusing on Group A): In Group A, for internal ranging: Device 5 initially acts as the receiver, receiving ranging packets from IDs 0 to 4 sequentially, calculating and storing the distances to these devices. When the transmission right falls to ID 5, device 5 switches to transmit mode and broadcasts the ranging packet. At this time, all other devices in the network (IDs 0-4, 6-51) turn on their receivers and calculate their distances to device 5; each receiver stores the ranging values. After transmission is complete, device 5 returns to the receive mode.

[0033] Other groups measure distances to Group A: Device 5, as a member of Group A, continuously receives distance measurement packets from ID13~51 to obtain the distances to all non-Group A devices.

[0034] Phases ② to ④: During these phases, device 5 primarily acts as the sender, broadcasting ranging packets to specific target groups. Specifically: In the second phase, the "range measurement between other groups and group B" sub-phase, device 5 transmits a ranging packet for group B (ID13~25) devices to receive.

[0035] In the "Range Measurement of Group C by Other Groups" sub-stage of Phase ③, device 5 transmits ranging packets for Group C (ID26~38) devices to receive.

[0036] In the fourth stage, the "range measurement between other groups and group D" sub-stage, device 5 transmits a ranging packet for group D (ID39~51) devices to receive.

[0037] Device 5 does not participate in the internal mutual ranging sub-stage of groups B, C, and D.

[0038] Phase 5: This round of ranging ends, automatically resets, and begins the next cycle.

[0039] Through the above complete cycle, device 5 obtains distance measurements with every other device in the network, realizing fully distributed ranging.

[0040] Example 3: Anomaly Handling Scenario – Target Device Missing This embodiment follows the grouping rules of Embodiment 1, assuming that no device with short ID 23 is deployed in the network (one device is missing in Group B), and all other devices are present.

[0041] In the first phase of the "Other Groups Ranging A Group" process, after the ID22 device completes packet transmission, all devices switch to receiving mode and wait for the ID23 device to transmit packets.

[0042] Since ID23 does not exist, after a 15-millisecond extended waiting window, none of the devices received a valid ranging packet.

[0043] At this point, the exception handling mechanism of each device is triggered, and they increment the expected next sender ID from 23 to 24 and begin waiting for the packet with ID 24.

[0044] ID24 sent the packet on time, and the ranging process resumed normal execution.

[0045] Throughout the process, the network only lost one packet transmission slot corresponding to ID23 (resulting in a 15-millisecond delay), without causing scheduling blockage or system paralysis. This mechanism is also applicable to packet loss caused by temporary interference such as signal obstruction, as well as similar anomalies occurring in stages ②, ③, and ④, effectively ensuring the continuity of the ranging process and the robustness of the system.

[0046] In summary, compared with existing technologies, this invention forms a complete technical solution through four core differentiating technologies, effectively solving the technical problems existing in current UWB ranging systems, such as central node dependence, severe channel conflicts, weak anomaly handling capabilities, and insufficient full network coverage, as detailed below: First, this invention abandons the traditional mode of fixed grouping, central node control or random access in the prior art. Through a dynamic self-organizing network mechanism, the device can spontaneously complete the identification sorting, group determination and time synchronization without manual intervention or central node scheduling. This improves the system's flexibility and environmental adaptability, and avoids the adaptation limitations caused by fixed grouping and the overall paralysis caused by central node failure.

[0047] Secondly, compared with the random access or polling + response mode of the existing technology, the present invention adopts a one-to-many broadcast ranging with strict timing. All devices take turns sending in ascending order of short ID, and the other devices receive synchronously. This not only reduces the channel conflict caused by multiple devices sending at the same time, but also reduces the amount of uplink data transmission and improves ranging efficiency through the design of "only the receiver stores the distance value".

[0048] Third, the present invention adopts a grouped and phased fully connected ranging architecture, which decomposes the ranging task into multiple group central stages. Each stage completes cross-group and intra-group ranging in an orderly manner, ensuring that distance measurement can be achieved between any two devices in the entire network, realizing full network coverage and solving the technical defect that some devices in the traditional ranging system cannot achieve interconnection.

[0049] Fourth, for abnormal scenarios such as device offline and signal loss, the abnormal skip-order waiting method based on time-series prediction designed in this invention is different from the simple retransmission or error reporting mechanism of the existing technology. By combining fixed-length delay waiting with automatic skip-order, it not only reserves a reasonable margin for signal propagation and device response, but also avoids process blockage caused by infinite waiting, thus ensuring the continuity of the ranging process and the robustness of the system.

[0050] Therefore, the distributed ranging scheduling method based on UWB provided by this invention addresses the problems of existing distributed ranging schemes, such as reliance on a central node, susceptibility to system paralysis due to main device failure, limited ranging range, reliance on high-precision clock synchronization, and complex deployment. This method offers the following advantages: First, it eliminates the risk of single point of failure by eliminating the need for a central node.

[0051] This invention utilizes a dynamic self-organizing network mechanism, enabling each device to autonomously complete identifier sorting, group determination, and timing synchronization without requiring a pre-set master device. The failure or offline status of a single device does not affect the normal ranging operations of other devices, avoiding the problem of the entire ranging network failing due to the paralysis of the master device in traditional solutions.

[0052] Second, it breaks through the limitations of ranging range.

[0053] This invention adopts a distributed peer-to-peer architecture, and ranging does not depend on the radio frequency coverage of the central node. Any two devices can complete ranging as long as they are within each other's communication range, making it suitable for large-scale, wide-area distributed ranging scenarios.

[0054] Third, it eliminates the reliance on high-precision clock synchronization.

[0055] This invention employs an abnormal skipping waiting method based on timing prediction. The device does not need to rely on the synchronous clock to determine timeouts. Instead, it ensures process continuity by combining fixed-length delay waiting with automatic skipping, thereby reducing the system's requirements for clock synchronization accuracy.

[0056] Fourth, simplify deployment and reduce operation and maintenance costs.

[0057] This invention eliminates the need for manual role assignment, periodic beacon synchronization maintenance, and dedicated synchronization chips. The device automatically completes network formation and ranging scheduling after power-on, significantly reducing deployment complexity and hardware costs.

[0058] In summary, this invention organically combines dynamic self-organizing networks, strict timing scheduling, grouped and phased ranging, and anomaly handling to form a distributed UWB ranging solution that requires no central node, does not rely on clock synchronization, and is easy to deploy. It eliminates the risk of single-point failure, improves the ranging range, eliminates the dependence on high-precision clock synchronization, and reduces deployment complexity and hardware costs. It can be widely used in scenarios requiring distributed ranging of multiple devices, such as UAV swarm formation, factory collision avoidance warning, and emergency search and rescue.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A distributed ranging and scheduling method based on UWB, characterized in that, Includes the following steps: S1. Preset rules: Determine the unique identifier for each UWB ranging device, and preset the identifier sorting rules and device grouping rules; S2, self-organizing network: Each device broadcasts its own identifier and listens to the broadcasts of other devices. Based on the received identifier information, it constructs an ordered local device list and autonomously determines its own group and ranging time sequence based on the ordered list and preset grouping rules, thus forming a distributed ranging network. S3. Ordered ranging: All devices take turns as the sender according to the ranging sequence, broadcasting ranging packets; the remaining devices receive the ranging packets and calculate the distance value; the ranging process is executed in a phased sequence centered on each group. During the ordered ranging process, if the receiver does not receive the ranging packet from the corresponding sender in the expected sequence, a preset delay time is initiated. If the packet is still not received after the timeout, the process automatically jumps to the next sender in the sequence number to continue execution, ensuring that the ranging process is continuous and uninterrupted.

2. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, The unique identifier is a short ID with consecutive numbers, and the identifier sorting rule is to arrange them in ascending or descending order of short ID value. The ranging time sequence is consistent with the identifier sorting order.

3. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, The device grouping rule is as follows: the devices in the ordered local device list are divided into N groups according to their sorting position, where N is an integer greater than or equal to 1.

4. The distributed ranging and scheduling method based on UWB according to claim 3, characterized in that, The number of devices in each group shall not exceed the preset maximum value, and the number of devices in any group shall be at least 2.

5. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, The phased time sequence centered on each group specifically includes: The first phase, centered on the first group, involves sequentially completing the mutual distance measurement between devices within the group, as well as the distance measurement between devices from other groups and the devices in that group. The second phase, centered on the second group, involves sequentially measuring the distance between the devices in other groups and the devices within that group, as well as measuring the distance between each other within the same group. This process continues until all groups have completed the distance measurement in turn, serving as the center in turn. After the current ranging cycle ends, it will automatically return to the starting point of the first stage and begin the next ranging cycle.

6. The distributed ranging and scheduling method based on UWB according to claim 5, characterized in that, Each stage specifically includes: First sub-phase: Other group devices take turns acting as transmitters to measure the distance to the central group's devices in this phase; Second sub-phase: In this phase, the devices within the central group act as transmitters in turn, measuring distances to other devices within the group. Third sub-phase: The remaining devices in other groups take turns as transmitters to measure the distance to the devices in the central group of this phase.

7. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, The preset duration is greater than or equal to the time required for a single device to complete one ranging packet transmission.

8. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, The duration of the self-organizing network step is a preset time period during which the devices continuously broadcast and listen to ensure that a complete and orderly list of local devices is obtained through convergence.

9. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, The ranging packet is sent in a broadcast manner to achieve one-to-many ranging with multiple receivers receiving a single transmission; the calculated distance value is only recorded and stored by the receiver, and the sender does not store the distance value of this ranging measurement.

10. The distributed ranging and scheduling method based on UWB according to claim 1, characterized in that, In the self-organizing network step, the devices alternately broadcast and listen at intervals. After the self-organizing network is completed, each device determines its own group according to its unique identifier in the ordered local device list and the device grouping rules, and determines its own transmission order in the ranging timing according to the identifier sorting rules.

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