AGVs, AGV traffic management method based on light frequency monitoring, and AGV traffic management system

Abstract

This invention proposes an AGV traffic management method, AGV traffic management system, and AGV based on light frequency monitoring. The method includes continuously emitting a modulated light signal with a first current frequency while continuously monitoring modulated light signals from the external environment during operation. When a modulated light signal with a second frequency from another AGV is detected, the second frequency is compared with the first current frequency. The AGV's driving state is controlled based on the comparison result: if the first current frequency is higher than the second frequency, the AGV maintains its current driving state; if the first current frequency is lower than the second frequency, the AGV enters a waiting state. This invention uses an optical transceiver module installed in the direction of movement of each AGV. The software in the module performs logical judgments based on the module's transmission and reception frequencies, and then controls the AGV's start and movement operations, resulting in simple logic and easy-to-understand operation.

Description

Technical Field

[0001] This invention relates to the field of electric bicycle motor technology, specifically demonstrating an AGV, an AGV traffic management method based on light frequency monitoring, and an AGV traffic management system. Background Technology

[0002] In traditional RCS (Automatic Guided Vehicle) systems, traffic control of AGVs is achieved by reporting AGV coordinates in real time. This method is highly dependent on the accuracy and timeliness of the AGV's reports. The RCS server calculates and determines whether the AGV can continue moving or stop. This method involves a high degree of coupling and dependence between the hardware and the server's calculations. In addition, the warehouse network must have low latency, and the coordinates and other information reported by the AGV itself need to be calibrated every time it goes online. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide an AGV, an AGV traffic management method based on light frequency monitoring, and an AGV traffic management system, thereby solving the aforementioned technical problems in the prior art.

[0004] The technical solution is as follows: Firstly, a method for managing AGV traffic based on light frequency monitoring is provided. This method is executed autonomously by the AGV and includes the following steps: During operation, it continuously emits modulated light signals with a first current frequency and continuously listens for modulated light signals from the external environment. When a modulated optical signal with a second frequency is detected from another AGV, the second frequency is compared with the first current frequency. The driving state of this AGV is controlled according to the comparison results: if the first current frequency is higher than the second frequency, the AGV is controlled to maintain the current driving state; if the first current frequency is lower than the second frequency, the AGV is controlled to enter the waiting state.

[0005] According to one embodiment of the present invention, controlling the driving state of the AGV based on the comparison result further includes: When the first current frequency is lower than the second frequency, the AGV is controlled to enter a waiting state and continuously monitors the external environment. When it is determined that the modulated optical signal of the second frequency disappears or weakens to below a preset threshold, the AGV is controlled to exit the waiting state and resume driving.

[0006] Based on the above technical solution, before the step of comparing the second frequency with the first current frequency, the method further includes: If the second frequency detected is the same as the first current frequency, then the transmission frequency of this AGV is adjusted to form a new first current frequency until it is different from the second frequency, and then a comparison is made.

[0007] Furthermore, the adjustment of the AGV's transmission frequency is as follows: within a preset frequency adjustment range, a frequency higher than the current value is randomly selected as the new first current frequency.

[0008] Furthermore, after controlling the AGV to maintain its current driving state through the target area, the method also includes: restoring the frequency of the modulated optical signal emitted by the AGV to a fundamental frequency.

[0009] Secondly, an AGV that applies the method described in the first aspect is provided, wherein the AGV integrates: The optical emission module is located at the front of the AGV body and is used to emit frequency-modulated optical signals. An optical receiver module is used to receive optical signals from the external environment; The control processing module, connected to the optical transmitting module and the optical receiving module, is configured to perform the following: Control the optical emission module to emit a modulated optical signal at a first current frequency; The signal from the optical receiving module is processed to identify modulated optical signals with a second frequency from other AGVs. Compare the first current frequency with the second frequency; Based on the comparison results, control commands are generated: when the first current frequency is lower than the second frequency, a stop and wait command is generated; otherwise, a normal driving command is generated. It also includes a vehicle drive module, which is connected to the control processing module and is used to execute driving actions according to control commands.

[0010] The light emitting module includes a light-emitting device for generating visible or infrared light and a driving modulation circuit; the light receiving module includes a photoelectric conversion device and a signal processing circuit connected to the control processing module, wherein the signal processing circuit is used to demodulate the modulation frequency from the received light signal.

[0011] Thirdly, an AGV traffic management system is provided, including multiple AGVs as described in the second aspect; Each AGV determines its own passage priority at intersections based on an autonomous comparison between the frequency of its own emitted optical signal and the frequency of optical signals received from other AGVs, thereby achieving distributed traffic management.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: an optical transceiver module is installed in the direction of movement of each AGV, and the software in the module makes logical judgments based on the module's transmission and reception frequency, and then controls the AGV vehicle to start and move.

[0013] The RCS system reduces traffic management modules, significantly lowering the performance and computational requirements of the server. There are no longer requirements for AGVs to report their current coordinates and for timeliness. All traffic management functions are delegated to the AGVs, which only need to execute simple judgment logic. Regardless of the number of AGVs in the warehouse, server computation is no longer a bottleneck. Task execution is divided into light frequency transmission and reception between several AGVs in a single block, independent of the current status and coordinates of all other AGVs in the entire warehouse. A single AGV can easily integrate this transceiver module to control its start and stop. The implementation logic is simple, easy to understand and operate, and aims to more closely resemble the obstacle avoidance maneuvers between people in the real world. Attached Figure Description

[0014] Figure 1 This is a flowchart of the AGV traffic management method of the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0016] Example 1: This embodiment provides a hardware system composition for an AGV. Based on the navigation, drive, and power supply modules of a traditional AGV, the system integrates an optical transmitting module, an optical receiving module, and a control processing module.

[0017] A light-emitting module is one or more light-emitting devices, such as high-brightness LEDs or low-power laser diodes, preferably emitting invisible infrared light to reduce visual interference with the working environment and enhance resistance to ambient light interference. The light-emitting module has a modulation drive circuit that receives instructions from the control processing module and converts a constant light output into a modulated light signal that flickers at a specific frequency.

[0018] An optical receiving module typically includes a photoelectric sensor with a large receiving angle, such as a photodiode or phototransistor, to receive light from within the front hemisphere. This sensor is followed by a signal conditioning and demodulation circuit. This circuit first filters the light to suppress ambient light interference, then amplifies the weak AC signal. The frequency demodulation unit detects the presence of a valid modulation frequency in the received optical signal, analyzes the value of that frequency, and reports it to the control processing module.

[0019] The control processing module can be a software functional unit of the AGV main controller or an independent microprocessor. It runs the designed traffic management logic program, including: setting and adjusting its own transmission frequency; parsing the external frequency reported by the optical receiver module; executing frequency comparison logic; and generating vehicle control commands based on the comparison results. This module has a clear interface with the AGV's vehicle drive control module, directly controlling the AGV's movement and stopping by sending simple signals.

[0020] Example 2: Based on the AGV of Embodiment 1, this embodiment proposes an AGV traffic management method based on light frequency monitoring, including the following steps: S1. After AGV No. 1 starts, the control processing module initializes the optical transmitting module and continuously transmits modulated light at a preset frequency f1. At the same time, the optical receiving module continuously monitors the environment. In this state, since no valid modulated light signal from other AGVs is detected, AGV No. 1 is in a free-moving state and normally performs the handling tasks issued by RCS.

[0021] S2. When AGV No. 1 travels to an intersection or other areas where other AGVs may appear, its optical receiving module may capture the modulated light emitted by other AGVs. The signal processing circuit identifies the valid modulated signal from the noise and demodulates its frequency value f2.

[0022] S3. The control processing module compares the frequency value f2 demodulated by S2 with the preset frequency f1 in S1.

[0023] If f1 is greater than f2, it means that the current passage priority of AGV No. 1 is higher than that of other detected AGVs. According to the principle of high frequency priority, AGV No. 1 obtains the right of passage and continues to pass. The control processing module does not interfere with the vehicle drive. AGV No. 1 continues to drive normally. At the same time, it continues to monitor the environment to prevent other vehicles with lower priority from appearing.

[0024] If f1 is less than f2, it means that the current passing priority of the first AGV is lower than that of other detected AGVs. The first AGV should stop and wait. The control processing module immediately sends a stop or pause instruction to the first AGV. The first AGV stops in front of the intersection or within a safe distance. After entering the waiting state, the first AGV still emits signals at a preset frequency and continues to monitor the environment.

[0025] If f1 = f2, it means that the light emission frequencies of the first AGV and other detected AGVs are exactly the same. At this time, the control processing module randomly increases the light emission frequencies of the two AGVs and compares them with the updated frequencies. The one with the higher frequency has the priority to pass, and the one with the lower frequency stops and waits.

[0026] S4. The waiting first AGV will still continuously monitor the signals from other high-frequency AGVs in the environment. Since the light emission module usually points to the front of the vehicle, when a high-frequency other AGV passes through the intersection in front of the waiting first AGV, the signal intensity received by the waiting first AGV will gradually attenuate with the change of distance. The control processing module will set a signal intensity threshold. When it detects that the signal intensity from the high-frequency AGV is lower than this threshold, it can be judged that the high-frequency AGV has passed and left the intersection area.

[0027] At this time, the control processing module cancels the stop instruction of the first AGV, and the first AGV restarts and passes through this intersection.

[0028] Embodiment 3: Taking the scenario where two AGVs are driving vertically towards each other at an intersection as an example, the working process of this method is demonstrated.

[0029] In the initial stage, the first AGV drives from west to east with a light emission frequency of a, and the second AGV drives from south to north with a light emission frequency of b, where a > b. When they have not entered the signal reception range of each other, both emit signals at their own frequencies and do not receive the signals of the other party, so they both drive freely.

[0030] In the encounter stage, the two AGVs enter the intersection area at the same time and enter the coverage range of each other's signals. The first AGV receives a signal with a frequency of b and compares it with its own frequency a. Since a > b, the first AGV judges that its own priority is high and decides to continue passing. The second AGV receives a signal with a frequency of a and compares it with its own b. Since b < a, the second AGV judges that its own priority is low and decides to stop and wait. The second AGV stops in front of the intersection.

[0031] The second AGV detects that the signal strength from frequency a is lower than a preset threshold. It determines that the first AGV has passed the intersection, so the second AGV starts and begins to pass through the intersection. At the same time, the first AGV, which has already passed the intersection, resets its transmission frequency from level a back to its basic frequency since its optical receiving module has not detected any other valid competing signals, in preparation for the next possible interaction.

[0032] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for AGV traffic management based on light frequency monitoring, characterized in that, The method is executed autonomously by the AGV and includes the following steps: During operation, it continuously emits modulated light signals with a first current frequency and continuously listens for modulated light signals from the external environment. When a modulated optical signal with a second frequency is detected from another AGV, the second frequency is compared with the first current frequency. The driving state of this AGV is controlled according to the comparison results: if the first current frequency is higher than the second frequency, the AGV is controlled to maintain the current driving state; if the first current frequency is lower than the second frequency, the AGV is controlled to enter the waiting state.

2. The AGV traffic management method based on light frequency monitoring according to claim 1, characterized in that, The method of controlling the driving state of this AGV based on the comparison results also includes: When the first current frequency is lower than the second frequency, the AGV is controlled to enter a waiting state and continuously monitors the external environment. When it is determined that the modulated optical signal of the second frequency disappears or weakens to below a preset threshold, the AGV is controlled to exit the waiting state and resume driving.

3. The AGV traffic management method based on light frequency monitoring according to claim 1 or 2, characterized in that, Before the step of comparing the second frequency with the first current frequency, the method further includes: If the second frequency detected is the same as the first current frequency, then the transmission frequency of this AGV is adjusted to form a new first current frequency until it is different from the second frequency, and then a comparison is made.

4. The AGV traffic management method based on light frequency monitoring according to claim 3, characterized in that, The method for adjusting the transmission frequency of this AGV is as follows: within a preset frequency adjustment range, a frequency higher than the current value is randomly selected as the new first current frequency.

5. The AGV traffic management method based on light frequency monitoring according to claim 4, characterized in that, After controlling the AGV to maintain its current driving state through the target area, the method also includes: restoring the frequency of the modulated optical signal emitted by the AGV to a fundamental frequency.

6. An AGV employing the method described in any one of claims 1-5, characterized in that, AGV integrates: The optical emission module is located at the front of the AGV body and is used to emit frequency-modulated optical signals. An optical receiver module is used to receive optical signals from the external environment; The control processing module, connected to the optical transmitting module and the optical receiving module, is configured to perform the following: Control the optical emission module to emit a modulated optical signal at a first current frequency; The signal from the optical receiving module is processed to identify modulated optical signals with a second frequency from other AGVs. Compare the first current frequency with the second frequency; Based on the comparison results, control commands are generated: when the first current frequency is lower than the second frequency, a stop and wait command is generated; otherwise, a normal driving command is generated. It also includes a vehicle drive module, which is connected to the control processing module and is used to execute driving actions according to control commands.

7. An AGV according to claim 6, characterized in that, The light emitting module includes a light-emitting device for generating visible or infrared light and a driving modulation circuit; the light receiving module includes a photoelectric conversion device and a signal processing circuit connected to the control processing module, wherein the signal processing circuit is used to demodulate the modulation frequency from the received light signal.

8. An AGV traffic management system, characterized in that, Includes multiple AGVs as described in claim 6 or 7; Each AGV determines its own passage priority at intersections based on an autonomous comparison between the frequency of its own emitted optical signal and the frequency of optical signals received from other AGVs, thereby achieving distributed traffic management.

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