Dual-encoder based secure laser switching zone control device

Abstract

The application provides a safe laser switching area control device based on double encoders, and relates to the field of logistics storage and vehicle automation control. The safe laser switching area control device based on double encoders improves the safety and reliability of the laser switching area of unmanned vehicles. Specifically, the device comprises a safety controller, two groups of encoders respectively located on two groups of driving wheels, and two groups of safety obstacle avoidance lasers installed on a vehicle body. The safety controller is used for collecting speed signals of the double encoders on the two groups of driving wheels, comparing the speeds of the two groups of wheels, segmenting and integrating the speeds, and processing the logical relationship according to the speed integration result. The safety controller outputs the logical relationship processing result to control the partition switching of the two groups of safety obstacle avoidance lasers.

Description

Technical Field

[0001] This application relates to the field of logistics warehousing and vehicle automation control, specifically proposing a control device based on dual encoders to achieve safe laser switching area monitoring and handling. Background Technology

[0002] Currently, various material handling devices, such as unmanned AGVs (Automated Guided Vehicles), are widely used in logistics warehousing and automated production sites to transport various materials. Existing obstacle detection for unmanned vehicles, both domestically and internationally, primarily employs lidar environmental perception to acquire surrounding environmental information for autonomous decision-making and navigation control.

[0003] The laser-based area switching method primarily involves the onboard controller controlling the laser switching area via I / O based on the conditions along the travel path and using signals from laser-detected objects to determine whether the unmanned vehicle should decelerate or stop. In complex situations, this method is prone to failure in determining the switching area or malfunction of the LiDAR, leading to control failures in deceleration or stopping the vehicle. This often poses safety hazards such as collisions and injuries, and exhibits low stability and reliability.

[0004] In view of the above, this patent application is hereby filed. Summary of the Invention

[0005] The safety laser switching area control device based on dual encoders described in this application aims to solve the problems existing in the prior art by proposing a solution for the safety laser switching area based on dual encoders, in order to improve the safety and reliability of the laser switching area of ​​unmanned vehicles.

[0006] To achieve the above design objectives, the dual-encoder-based safety laser switching area control device includes a safety controller that communicates with each other, two sets of encoders located on the two drive wheel sets respectively, and two sets of safety obstacle avoidance lasers mounted on the vehicle body. The safety controller is used to collect the speed signals of the dual encoders on the two drive wheel sets, compare the speeds of the two wheel sets, segment and integrate the speeds, and perform logical relationship processing based on the speed integration results. The safety controller outputs the logical relationship processing results to control the zone switching of the two sets of safety obstacle avoidance lasers.

[0007] Furthermore, the two sets of safety lasers are located on the front sides of the vehicle body, forming an obstacle avoidance detection range of 180°-270° in front of and on both sides of the vehicle body.

[0008] Furthermore, the safety controller comprises a safety PLC module, a safety IO module, an Ethernet communication module, a safety Ethernet module, an encoder MOC1 module, and an encoder MOC2 module. The encoder MOC1 module communicates with the two encoders on the motor of the left drive wheel set and uploads the running speed and status data of the left wheelset to the safety PLC module. The encoder MOC2 module communicates with the two encoders on the motor of the right drive wheel set and uploads the running speed and status data of the right wheelset to the safety PLC module. The safety IO module is connected to the vehicle's power supply and can cut off the power supply according to the command signal from the safety PLC module. The Ethernet communication module is connected to the vehicle's main control device and transmits the command signal from the main control device to the safety PLC module. The safety Ethernet module communicates with the two sets of safety obstacle avoidance lasers and outputs the partition signal processed by the safety PLC module to either of the two sets of safety obstacle avoidance lasers to realize the partition switching of the safety obstacle avoidance detection area.

[0009] Furthermore, the safety PLC module includes a left and right wheel segmented speed integration module and a segmented speed logic relationship processing module; the left and right wheel segmented speed integration module is used for segmenting and integrating the motion speed of each wheel pair and judging the turning state; the segmented speed logic relationship processing module is used to process the input signal of the left and right wheel segmented speed integration module through logic relationship to obtain the results of two sets of safety obstacle avoidance laser switching areas.

[0010] As mentioned above, the advantages and beneficial effects of this application compared to the prior art are that by setting up a safety controller to detect and monitor the dual encoder signals of the left and right drive wheel motors, it can effectively realize the real-time processing of logical relationships such as dual wheel speed detection, speed segmentation, and speed integration. It can subdivide the dual wheel speed into low speed, medium speed, and high speed, as well as left turn and right turn, and then perform logical processing according to different vehicle operating states, stably and accurately output the switching area signal to the safety laser, and finally realize automatic switching of laser area and protection during overspeed and low-speed turns. It does not require processing by the vehicle main control, and has high safety and reliability. Attached Figure Description

[0011] The present application will now be further illustrated with reference to the following figures.

[0012] Figure 1 This is a schematic diagram of the safety laser switching area control device based on dual encoders proposed in this application; Figure 2 This is a block diagram of the safety controller; Figure 3 This is a block diagram of the encoder MOC1 module of the safety controller; Figure 4This is a block diagram of the encoder MOC2 module structure of the safety controller; Figures 5 to 7 This is a block diagram of the left and right wheel segmented speed integration module of the safety PLC module; Figure 8 This is a block diagram of the segmented speed logic relationship processing module of the safety PLC module; Detailed Implementation

[0013] Example 1, such as Figure 1 As shown, an AGV using the dual-encoder-based safety laser switching area control device described in this application includes a vehicle body, with two sets of drive wheel sets and two sets of safety obstacle avoidance lasers LS1 and LS2 respectively arranged on both sides of the vehicle body. Each drive wheel set includes a motor, reducer, and brake, etc., equipped with two encoders (such as E1 and E2, E3 and E4) to control the running state of the wheel set. This AGV can only move forward and turn left and right according to the usage scenario. Therefore, the two sets of safety obstacle avoidance lasers LS1 and LS2 only perform obstacle avoidance detection in front and on the left and right sides. Simultaneously, the maximum straight-line speed of this AGV is set not to exceed 2 m / s, and the turning speed is set not to exceed 0.3 m / s.

[0014] The safety laser switching area control device based on dual encoders proposed in this application includes a safety controller, two sets of encoders (E1 and E2, E3 and E4) located on the two drive wheel sets respectively, and two sets of safety obstacle avoidance lasers (LS1 and LS2) installed on the vehicle body. The safety controller is used to collect speed signals from the dual encoders (E1 and E2, E3 and E4) on the two sets of drive wheel sets, compare the speeds of the two wheel sets, segment and integrate the speeds, and perform logical relationship processing based on the speed integration results. The safety controller outputs the logical relationship processing results to control the zone switching of the two sets of safety obstacle avoidance lasers. Two sets of safety lasers, LS1 and LS2, are located on the front sides of the vehicle body, respectively, and can perform obstacle avoidance detection within a range of 180°-270° in front and to the sides. Each drive wheel assembly has two sets of encoders on its motor. One set is the main encoder, which collects the speed and status signals of the motor driver and outputs the corresponding signals through the differential drive chip. The other set of encoders is the auxiliary encoder, which is used to transmit the corresponding speed and status signals to the safety controller. The dual encoder setup is mainly for safety strategy considerations. The safety controller can only collect signals for logical processing when both encoders are working properly; otherwise, an alarm will be triggered. Each encoder and safety obstacle avoidance laser communicates with the safety controller. The encoder uploads the running speed and status data of the wheelset to the safety controller. After processing the data with logic, the safety controller outputs a partition signal to the two sets of safety obstacle avoidance lasers. This allows for the switching of the laser safety obstacle avoidance detection area based on the running speed (e.g., low speed, medium speed, or high speed) and running status (e.g., left turn or right turn). When the wheelset exceeds the speed limit in straight-line motion or when turning, the safety controller cuts off the vehicle's main power supply without the need for intervention from the onboard main control device.

[0015] like Figure 2 As shown, the safety controller consists of a safety PLC module, a safety IO module, an Ethernet communication module, a safety Ethernet module, an encoder MOC1 module, and an encoder MOC2 module. Specifically, the encoder MOC1 module (such as...) Figure 3 (As shown) It communicates with the two encoders E1 and E2 on the motor of the left drive wheel set and uploads the running speed and status data of the left wheel set to the safety PLC module; Encoder MOC2 module (such as) Figure 4 (As shown) It communicates with the two encoders E3 and E4 on the motor of the right drive wheel set and uploads the running speed and status data of the right wheel set to the safety PLC module. The safety I / O module is connected to the vehicle's power supply and can cut off the power supply according to the command signal of the safety PLC module. The Ethernet communication module is connected to the vehicle's main control unit, and it transmits the command signals from the main control unit to the safety PLC module. The secure Ethernet module communicates with two sets of safety obstacle avoidance lasers, LS1 and LS2, respectively. It outputs the partition signal processed by the safety PLC module to either of the two sets of safety obstacle avoidance lasers to realize the partition switching of the safety obstacle avoidance detection area. The safety PLC module includes a left and right wheel segmented speed integration module (such as...) Figures 5 to 7 As shown), the segmented speed logic relationship processing module (such as...) Figure 8 (As shown); the left and right wheel segmented speed integration module is used for segmenting and integrating the motion speed of each wheel pair, as well as judging the turning state; the segmented speed logic relationship processing module is used to process the input signals of the left and right wheel segmented speed integration module through logic relationship to obtain the results of two sets of safety obstacle avoidance laser switching areas.

[0016] Figure 3The encoder MOC1 module includes a speed comparison module U1, which is connected to the left wheel encoders E1 and E2. The speed comparison module U1 collects and calculates the input signals of encoders E1 and E2, and the encoder with the larger calculated value is used as the output result of the speed comparison module U1 and output to the speed segmentation module U7 and speed segmentation module U2 respectively. The speed segmentation module U7 and speed segmentation module U2 divide the input speed range into segments and output them to Boolean converter U3 and Boolean converter U8 in speed ID format, while determining the left wheel direction signal. Specifically, the output of one speed ID is converted into a 3-bit binary number by the speed segmentation module U7 and the Boolean converter U8, such as O1, O2, O3 from low to high bits; the output value of Boolean converter U8 is passed through AND gate U9 to obtain the speed range SL4 (left wheel low speed 0-0.3m / s) using Boolean quantity; the output value of Boolean converter U8 is passed through AND gate U10 to obtain the speed range SL5 (left wheel medium speed 0.3-1m / s) using Boolean quantity; the output value of Boolean converter U8 is passed through AND gate U11 to obtain the speed range SL6 (left wheel high speed 1-2m / s) using Boolean quantity; the output value of Boolean converter U8 is passed through AND gate U12 to obtain the speed range SL7 (left wheel overspeed >2m / s); as shown in the table below: Table 1 1 0 0 still 2 Revolver speed: 0~0.3m / s 2 go ahead SL4 3 Revolver speed: 0.3~1m / s 3 go ahead SL5 4 Revolver 1~2m / s 4 go ahead SL6 5 Revolver > 2m / s 5 go ahead SL7 Another speed signal enters the speed segmentation module U2 to determine the speed control when the left wheel is turning; the maximum speed cannot exceed 0.3 m / s. The output of the speed ID is converted into a 3-bit binary number by the Boolean converter U3, with the low-order bits being O1, O2, and O3 respectively. The output value of the Boolean converter U8 is passed through AND gate U4 to obtain the speed range SL1 (left wheel 0-0.1 m / s) represented by Boolean values. The output value of the Boolean converter U3 is passed through AND gate U5 to obtain the speed range SL2 (left wheel 0.1-0.2 m / s) represented by Boolean values. The output value of the Boolean converter U3 is passed through AND gate U6 to obtain the speed range SL3 (left wheel 0.2-0.3 m / s) represented by Boolean values. See the table below: Table 2 1 0 0 still 2 Revolver 0~0.1m / s 2 go ahead SL1 3 Revolver speed: 0.1~0.2 m / s 3 go ahead SL2 4 Revolver speed: 0.2~0.3 m / s 4 go ahead SL3 Figure 4The encoder MOC2 module includes a speed comparison module U13, which is connected to the right wheel encoders E3 and E4 respectively. The speed comparison module U13 collects and calculates the input signals of encoders E3 and E4, and the encoder with the larger calculated value is used as the output result of the speed comparison module U13 and output to the speed segmentation module U14 and speed segmentation module U15 respectively. The speed segmentation module U14 and speed segmentation module U15 divide the input speed range into segments and output them to Boolean converters U16 and U17 in speed ID format, and at the same time determine the right wheel direction signal. Specifically, the output of one speed ID is converted into a 3-bit binary number by the speed segmentation module U15 and the Boolean converter U17, such as O1, O2, O3 from low to high bits; the output value of Boolean converter U17 is used by AND gate U21 to obtain the speed range represented by Boolean values: SR4 (right wheel low speed 0-0.3m / s); the output value of Boolean converter U17 is used by AND gate U22 to obtain the speed range represented by Boolean values: SR5 (right wheel medium speed 0.3-1m / s); the output value of Boolean converter U17 is used by AND gate U23 to obtain the speed range represented by Boolean values: SR6 (right wheel high speed 1-2m / s); the output value of Boolean converter U17 is used by AND gate U24 to obtain the speed range represented by Boolean values: SR7 (right wheel overspeed >2m / s); as shown in the table below: Table 3 1 0 0 still 2 Right wheel 0~0.3m / s 2 go ahead SR4 3 Right wheel speed: 0.3~1 m / s 3 go ahead SR5 4 Right wheel 1~2m / s 4 go ahead SR6 5 Right wheel >2m / s 5 go ahead SR7 Another speed signal enters the speed segmentation module U14 to determine the speed control when the right wheel is turning; the maximum speed cannot exceed 0.3 m / s. The output of the speed ID is converted into a 3-bit binary number by the Boolean converter U16, with the low-order bits being O1, O2, and O3 respectively. The output value of the Boolean converter U16 is passed through AND gate U18 to obtain the speed range SR1 (right wheel 0-0.1 m / s) represented by Boolean values. The output value of the Boolean converter U16 is passed through AND gate U19 to obtain the speed range SR2 (right wheel 0.1-0.2 m / s) represented by Boolean values. The output value of the Boolean converter U16 is passed through AND gate U20 to obtain the speed range SR3 (right wheel 0.2-0.3 m / s) represented by Boolean values. As shown in the table below: Table 4 1 0 0 still 2 Right wheel 0~0.1m / s 2 go ahead SR1 3 Right wheel speed: 0.1~0.2 m / s 3 go ahead SR2 4 Right wheel speed: 0.2~0.3 m / s 4 go ahead SR3 The safety PLC module's left and right wheel segmented speed integration module, such as... Figures 5 to 7 As shown, it integrates low-speed, medium-speed, and high-speed forward movement, as well as turning judgment. like Figure 5As shown, the vehicle can only be determined to be in a low-speed driving state when both the left and right wheels are in the low-speed range. For example, after passing the Boolean values ​​SL4 (left wheel low speed 0-0.3m / s) and SR4 (right wheel low speed 0-0.3m / s) through AND gate U25, the output Boolean value S1 is the vehicle's low-speed driving range of 0-0.3m / s. Only when the speeds of the left and right wheels are both within the medium speed range can it be determined that the vehicle is in a medium speed driving state; for example, after passing the Boolean quantity SL5 (left wheel low speed 0.3-1m / s) and the Boolean quantity SR5 (right wheel low speed 0.3-1m / s) through AND gate U26, the output Boolean quantity S2 is the vehicle's medium speed driving range of 0.3-1m / s. Only when the speeds of both the left and right wheels are in the high-speed range can it be determined that the vehicle is in a high-speed driving state. For example, after passing the Boolean quantity SL6 (left wheel high speed 1-2m / s) and the Boolean quantity SR6 (right wheel high speed 1-2m / s) through AND gate U27, the output Boolean quantity S3 is the vehicle's high-speed driving range of 1-2m / s. like Figure 6 As shown, the logic for determining a low-speed turn involves processing the right wheel speeds of SR2 (0.1-0.2 m / s) and SR3 (0.2-0.3 m / s) via OR gate U30. This determines the right wheel speed range to be between 0.1-0.3 m / s. Then, this is combined with the left wheel speed of SL1 (0-0.1 m / s) via AND gate U31, confirming the left wheel speed range to be between 0-0.1 m / s. Finally, the right wheel speed range is determined to be between 0.1-0.3 m / s, and the final determination is a left turn (S6) with a maximum speed not exceeding 0.3 m / s. Similarly, after processing the left wheel speeds of SL2 (0.1-0.2 m / s) and SL3 (0.2-0.3 m / s) through OR gate U32, the left wheel speed range is determined to be between 0.1-0.3 m / s. Then, after processing the right wheel speed of SR1 (0-0.1 m / s) through AND gate U33, the right wheel speed range is determined to be between 0-0.1 m / s, and the left wheel speed range is determined to be between 0.1-0.3 m / s. Finally, it is determined that S7 is a right turn, and the maximum speed does not exceed 0.3 m / s. like Figure 7 As shown, the overspeed and low-speed turning overspeed alarm processing, SL7 left wheel overspeed >2m / s and SR7 right wheel overspeed >2m / s are output through OR gate U28. As long as one wheel is overspeeding, the Boolean quantity S4 is output to protect the whole vehicle from overspeeding >2m / s. When turning, if the speed of the left wheel of SL5 is 0.3-1m / s, the speed of the left wheel of SL6 is 1-2m / s, the speed of the right wheel of SR5 is 0.3-1m / s, and the speed of the right wheel of SR6 is 1-2m / s, after output through OR gate U29, if any wheel speed exceeds 0.3m / s, it is determined that the speed is overspeeding when turning, and the Boolean value S5 is output to protect the vehicle from overspeeding > 0.3m / s when turning at low speed. Finally, the Boolean quantity S4 (overspeed protection > 2 m / s) and the Boolean quantity S5 (overspeed protection > 0.3 m / s during low-speed turning) are output as Boolean quantity S8 through OR gate U34 to the safety IO module, so as to cut off the power supply and stop the motor by braking, thus achieving the result of overspeed and low-speed turning protection.

[0017] The segmented speed logic relationship processing module of the safety PLC module, such as Figure 8 As shown, the input data includes Boolean values ​​S1 (vehicle low speed 0-0.3m / s), S2 (vehicle medium speed 0.3-1m / s), S3 (vehicle high speed 1-2m / s), DL1 (left wheel forward direction), DRL (right wheel forward direction), S6 (left turn), S7 (right turn), and a switch reset RESET; the output data includes LS1 (left laser switching area A), LS1 (left laser switching area B), LS1 (left laser switching area C), LS2 (right laser switching area A), LS2 (right laser switching area B), and LS2 (right laser switching area C). The logical relationship processing involves passing the input signal through AND gates, OR gates, and RS flip-flops to obtain the ABC distribution of the switching regions of LS1 and LS2 lasers. The final truth table relationship is shown in the table below: Table 5 1 S1 low speed 0-0.3m / s 1 0 0 1 1 0 2 S2 medium speed 0.3-1m / s 0 1 0 0 0 0 3 S3 Expressway 1-2m / s 0 0 1 0 0 0 4 DL1 Revolver Forward 1 1 1 1 1 0 5 DR1 right wheel forward 1 1 1 1 1 0 6 S6 left turn 0 0 0 0 0 0 7 S7 right turn 0 0 0 0 0 0 8 RESET reset 0 0 0 0 0 1 9 LS1 left laser A 1 0 1 0 1 0 10 LS1 left laser B 0 1 1 0 0 0 11 LS1 left laser C 0 0 0 1 1 0 12 LS2 right laser A 1 0 1 0 1 0 13 LS2 right laser B 0 1 1 0 0 0 14 LS2 right laser C 0 0 0 1 1 0 As can be seen from the table, when the vehicle is traveling at a low speed of 0-0.3 m / s in S1, the protection area of ​​lasers LS1 and LS2 is the first area ABC=001; when the vehicle is traveling at a medium speed of 0.3-1 m / s in S2, the protection area of ​​lasers LS1 and LS2 is the second area ABC=010; when the vehicle is traveling at a high speed of 1-2 m / s in S3, the protection area of ​​lasers LS1 and LS2 is the third area ABC=011; when the vehicle is turning left in S6, the protection area of ​​lasers LS1 and LS2 is the fourth area ABC=100; when the vehicle is turning right in S6, the protection area of ​​lasers LS1 and LS2 is the fifth area ABC=101; during reset, when the vehicle is at a stop, the protection area of ​​lasers LS1 and LS2 is cleared to ABC=000.

[0018] As described above, the safety controller detects and monitors the dual encoder signals of the left and right drive wheel motors, performs logical processing such as speed detection, speed segmentation, and speed integration, and classifies the speed into low speed, medium speed, high speed, left turn, right turn, etc. Based on the different operating states of the vehicle, it performs logical processing and outputs the laser switching area signal ABC, and transmits the switching signal to the safety laser. This achieves automatic switching of the laser area according to different speeds and turning conditions, and provides protection against overspeed and low-speed turns. It does not require processing by the on-board main controller, resulting in high safety and reliability.

[0019] The embodiments described above, in conjunction with the accompanying drawings, are merely preferred solutions for achieving the objectives of this utility model. Those skilled in the art can draw inspiration from this and directly derive other alternative structures that conform to the design concept of this utility model. Other structural features derived therefrom should also fall within the scope of the solutions described in this utility model.

Claims

1. A dual-encoder-based secure laser-switched area control device, characterized by: The safety controller, two groups of encoders respectively located on two groups of driving wheels, and two groups of safety obstacle avoidance lasers installed on the vehicle body are in data communication with each other. The safety controller is used for collecting speed signals of the double encoders on the two groups of driving wheels, comparing the speeds of the wheel sets on the two sides, segmenting and integrating the speeds, and processing the logical relationship according to the speed integration result. The safety controller outputs the logical relationship processing result to control the partition switching of the two groups of safety obstacle avoidance lasers.

2. The dual-encoder-based safe laser switching zone control apparatus according to claim 1, characterized in that: The two groups of safety lasers are respectively located on the front ends of the vehicle body, and form an obstacle avoidance detection range of 180-270 degrees in front of the vehicle body.

3. The dual-encoder-based safe laser switching zone control apparatus of claim 1, wherein: The safety controller is composed of a safety PLC module, a safety IO module, an Ethernet communication module, a safety Ethernet module, an encoder MOC1 module and an encoder MOC2 module. The encoder MOC1 module communicates with the two groups of encoders on the motor of the left driving wheel group, and uploads the running speed and state data of the left wheel set to the safety PLC module. The encoder MOC2 module communicates with the two groups of encoders on the motor of the right driving wheel group, and uploads the running speed and state data of the right wheel set to the safety PLC module. The safety IO module is connected with the power supply of the vehicle, and can cut off the power supply according to the instruction signal of the safety PLC module. The Ethernet communication module is connected with the main control device of the vehicle, and transmits the instruction signal of the main control device to the safety PLC module. The safety Ethernet module communicates with the two groups of safety obstacle avoidance lasers respectively, and outputs the partition signal processed by the safety PLC module to any one of the two groups of safety obstacle avoidance lasers.

4. The dual-encoder-based safe laser switching zone control apparatus of claim 3, wherein: The safety PLC module includes a left and right wheel segmented speed integration module and a segmented speed logical relationship processing module. The left and right wheel segmented speed integration module is used for segmenting and integrating the movement speed of each wheel set and judging the turning state. The segmented speed logical relationship processing module is used for processing the input signal of the left and right wheel segmented speed integration module through logical relationship.

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