Control system suitable for traction robot and control method thereof

Abstract

The invention relates to the field of industrial intelligence, in particular to a safety degree design in the connecting process of a traction robot and a skip car. The invention aims to provide a control system suitable for a traction robot and a control method of the control system. A dual judgment mechanism of position detection and current monitoring is integrated in a connecting device. Through double verification of the electric signals, the system can recognize the dangerous working conditions of virtual hanging and false disengaging in real time, and the safety level of operation of the traction robot and the intelligent level of an automatic system are improved.

Description

Technical Field

[0001] This invention relates to the field of industrial intelligence, specifically to the safety design during the connection process between a traction robot and a material cart. Background Technology

[0002] A traction robot is an automated guided vehicle (AGV) used in industrial intelligent logistics. Its core function is to provide power and navigation, enabling the automated flow of materials in warehouses, workshops, and other similar settings. A material cart is a non-powered cargo-carrying unit whose function is to carry goods. The front of the material cart typically has a docking mechanism, such as a pin hole, for establishing a physical connection with the traction robot. In material handling tasks, the material cart relies entirely on the traction force provided by the traction robot for movement.

[0003] In existing technologies, the physical connection between the traction robot and the material cart is mainly achieved through a pin structure. Specifically, a manually operable pin is installed on the traction robot. Correspondingly, a pin hole matching the pin is located at the front end of the material cart. When connection is needed, the operator manually aligns the pin with the pin hole on the material cart and inserts it, thereby achieving mechanical locking and completing the connection. When separation is needed, the pin must also be manually pulled out of the pin hole.

[0004] However, at the end of the task, if the operator fails to fully pull out the pin—for example, due to negligence, poor visibility, or misjudgment—and the control system mistakenly believes that the hook has been successfully disengaged, the towing robot will continue moving with the still-connected cart. The cart may be accidentally dragged into non-operational areas, colliding with equipment, shelves, or personnel; at the same time, this may also cause overload damage to the towing robot itself.

[0005] On the other hand, at the start of the task, if the pin is not precisely aligned with the material cart's pin hole before forcibly moving the traction robot, or if the pin is only partially inserted, the traction robot's activation at this point can easily lead to a rigid collision between the pin and the material cart's docking parts. This can not only cause the pin to bend and damage the material cart's structure, but also potentially cause the traction robot to stop abruptly or lose control due to the instantaneous impact force, even posing a threat to the safety of nearby personnel. This collision risk is particularly prominent under high-speed or high-load conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a control system and control method suitable for traction robots, in which a dual judgment mechanism of position detection and current monitoring is integrated into the connection device. Through dual verification of electrical signals, the system can instantly identify dangerous working conditions such as false engagement and decoupling, thereby improving the safety level of traction robot operation and the intelligence level of the automation system.

[0007] The present invention is achieved through the following technical solution: a control system suitable for a traction robot, comprising a connecting device for connecting to a material cart, the connecting device comprising a base and a traction shaft movably connected to the base;

[0008] The connecting device also includes a spring element and a push rod motor.

[0009] The elastic element is configured to drive the traction shaft into an unlocked state; the push rod motor is configured to drive the traction shaft to move, causing the traction shaft to overcome the elastic force of the elastic element and enter a locked state.

[0010] The control system also includes a current reading module, a height detection module, and an identification module;

[0011] The current reading module is configured to read the current value I of the push rod motor;

[0012] The height detection module is configured to read the height value H of the traction shaft;

[0013] The identification module is configured to determine the connection status based on the current value I and the height value H.

[0014] As a preferred embodiment of the present invention, when the current value I is greater than a preset first current threshold I1, and the height value H is lower than a preset first height threshold H1, the identification module determines that the current state is a locking completion state.

[0015] As a preferred embodiment of the present invention, when the current value I is less than a preset second current threshold I2, and the height value H is higher than a preset second height threshold H2, the identification module determines that the current state is the unlocking completion state.

[0016] As a preferred embodiment of the present invention, it further includes a positioning module, which includes a tag reading module for reading environmental tags. The positioning module is configured to determine whether a target point has been reached by reading the target point tag, and after reaching the target point, allow the push rod motor to drive the traction shaft to move.

[0017] As a preferred embodiment of the present invention, the positioning module further includes a distance calculation module;

[0018] The label reading module reads the labels of the pre-target points;

[0019] The distance calculation module is configured to calculate the distance d that the robot travels after reaching the pre-target point;

[0020] The positioning module is configured to determine that the target point has been reached only when the travel distance d reaches a preset value d1 and the tag reading module reads the target point tag.

[0021] As a preferred embodiment of the present invention, the distance calculation module calculates the travel distance d based on the traveling speed v of the traction robot and the time t elapsed after reaching the pre-target point.

[0022] The control system for a traction robot according to any one of the claims is characterized in that: the height detection module includes a lower detector and an upper detector disposed at different height positions on the base, the lower detector and the upper detector being used to detect the height position of the traction shaft.

[0023] As a preferred embodiment of the present invention, the traction shaft includes a vertically extending main shaft and a detection plate disposed on the main shaft. The detection plate is an annular detection plate that protrudes outward from the main shaft. Both the lower detector and the upper detector are contact sensors.

[0024] The control method for the control system of the traction robot includes the following steps:

[0025] S01. Parking Procedure;

[0026] The towing robot reaches the target point and stops moving.

[0027] S02, Data Reading Steps;

[0028] The height detection module reads the height value H of the traction shaft.

[0029] The current reading module reads the current value I of the push rod motor;

[0030] S03, Status Judgment Steps;

[0031] The separate module determines the connection status based on the current value I and the height value H.

[0032] As a preferred embodiment of the present invention, a pre-positioning step is further provided before step S01:

[0033] Before reaching the target point, the arrival at the target point is determined by reading the pre-target point label;

[0034] The robot determines whether it has reached the target point based on the distance traveled d after reaching the pre-target point and the target point label read.

[0035] As a preferred embodiment of the present invention, the elastic element is a spring, with one end abutting against the base and the other end abutting against the detection piece.

[0036] As a preferred embodiment of the present invention, the base includes a fixed seat and a back plate connected to the fixed seat, the back plate extends in a vertical direction, the traction shaft is connected to the base, and the traction shaft and the push rod motor are respectively located on both sides of the back plate.

[0037] As a preferred embodiment of the present invention, the base is provided with a guide cylinder, and one end of the traction shaft passes through the guide cylinder.

[0038] As a preferred embodiment of the present invention, the fixing base includes two guide fins, one above the other, which gradually open away from the back plate.

[0039] In summary, the present invention has the following beneficial effects:

[0040] 1. By introducing a dual detection mechanism of current and height, a state judgment method based on information fusion is constructed, thereby realizing the automatic judgment of connection status and locking / unlocking, effectively overcoming the unreliability of traditional solutions, and laying the foundation for the intelligent control and safe operation of the entire system.

[0041] 2. By introducing a positioning module and interlocking it with the hook action, the system is only allowed to perform connection or disconnection operations after confirming that it has reached the target point. This avoids equipment collisions or process chaos caused by misoperation in undesignated areas, thus enhancing system safety.

[0042] 3. A multi-verification positioning strategy combining pre-target point, travel distance, and target point. This strategy combines the advantages of relative and absolute positioning, improving the robustness and anti-interference capabilities of positioning, and effectively preventing premature or delayed operations caused by tag misreading or accumulated errors.

[0043] 4. The locking mechanism is achieved by using a push rod motor to provide power to overcome the force of the elastic component, and the automatic unlocking is achieved by using the self-restoring force of the elastic component. This completely replaces manual operation and improves the automation level and efficiency of the traction robot operation.

[0044] 5. By designing the push rod as a lever structure with a central hinge, the driving torque is amplified, the load requirements and energy consumption of the drive unit are reduced, and the motion process is made smoother and more reliable.

[0045] 6. Adding rollers between the push rod and the contact cover of the traction shaft reduces the frictional resistance and wear between the push rod and the contact cover. This not only reduces drive energy consumption and improves transmission efficiency, but also reduces operating noise and component wear, and extends the service life of the entire connection device.

[0046] 7. By installing a detection element that moves in tandem with the traction shaft, along with upper and lower detectors at different heights, a direct detection mechanism for the actual position of the traction shaft is established. This solution can provide real-time and accurate feedback on whether the traction shaft is locked or unlocked, providing crucial status judgment information for the control system and serving as a prerequisite for achieving safe control.

[0047] 8. The detection is performed using a contact sensor, which has strong anti-electromagnetic interference capability, stable and reliable signal, and can accurately determine whether the detection piece has arrived, thereby accurately confirming the limit position of the traction shaft and avoiding the false detection that may occur with non-contact sensors under complex working conditions. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of existing technology;

[0049] Figure 2 A schematic diagram of the traction robot in the embodiment is shown;

[0050] Figure 3 A schematic diagram of the connection device in the embodiment is shown;

[0051] Figure 4 A schematic diagram of the traction robot's route trajectory is shown;

[0052] Figure 5 A schematic diagram of the control system modules is shown.

[0053] In the diagram: 91. Fixed frame, 92. Pin, 11. Vehicle body, 12. Laser obstacle avoidance device, 13. Magnetic navigation device, 14. Walking device, 15. Warning light, 16. Camera assembly, 2. Connecting device, 21. Base, 211. Fixed seat, 212. Back plate, 213. Guide cylinder, 22. Shaft hole, 231. Lower detector, 232. Upper detector, 24. Elastic component, 251. Push rod, 252. Roller, 26. Traction shaft, 261. Contact cover, 262. Detection plate, 263. Main shaft, 27. Push rod motor. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to the accompanying drawings.

[0055] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings.

[0056] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0057] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of this specification. Various processes or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0058] As attached Figure 1 As shown, Figure 1 The existing connection structure between the traction robot and the material cart typically employs a purely mechanical pin-and-lock structure. This structure mainly includes a fixed frame 91 attached to the robot body and a manually operable pin 92. During operation, the operator needs to manually align the pin 92 and insert it into the corresponding pin hole at the front end of the material cart to complete the physical connection.

[0059] The fundamental flaw of this technical solution lies in its heavy reliance on manual operation and extremely low level of automation. This not only restricts the logistics system's ability to achieve end-to-end full-process automation, but also significantly increases the safety risk of human-machine collisions due to frequent human intervention. Furthermore, the inconsistent pace of manual operation becomes a bottleneck for system efficiency improvement, failing to meet the demands of modern industrial logistics for high-intensity, high-cycle operations. This invention is designed precisely to solve these problems.

[0060] The following will be combined with the appendix Figure 2 and Figure 3 The technical solution of the present invention will be described step by step.

[0061] As attached Figure 2 As shown, the traction robot in this embodiment includes a vehicle body 11 as its core load-bearing structure. A walking device 14 is installed at the bottom of the vehicle body 11, providing the robot with mobility. To ensure driving safety and accurate navigation, the vehicle body 11 also integrates a laser obstacle avoidance device 12, a magnetic navigation device 13, a warning light 15, and a camera assembly 16. The connecting device 2 is securely installed at one end of the vehicle body 11 at the rear, and its function is to achieve automatic, rapid, and reliable connection and separation between the robot and the material cart.

[0062] As attached Figure 3 As shown, the specific structure of the connecting device 2 includes a base 21, a traction shaft 26, a spring element 24, a push rod motor 27, and a high-precision status detection component.

[0063] The base 21 is the mounting foundation for the entire device, consisting of a fixed base 211 and a back plate 212. The back plate 212 can be rigidly connected to the vehicle body 11 by high-strength bolts to ensure effective transmission of force.

[0064] The mounting base 211 integrates two guide fins, one above the other. These fins gradually open away from the back plate 212, forming a funnel-shaped guide structure. A significant advantage of this design is that when the robot docks with the material cart, even with some initial positioning deviation, the opening ramps can automatically accommodate and guide the docking components of the material cart, such as the connecting plate with pin holes, into the correct position. This greatly reduces the stringent requirements on the robot's final positioning accuracy, thereby significantly improving the success rate and efficiency of docking and enhancing the system's robustness under various working conditions. In some embodiments, guide fins in the left and right directions are further added, with the same structure and principle as described above.

[0065] The backplate 212, as the main vertical structure, extends vertically, providing mounting positions for other components. The traction shaft 26 and the push rod motor 27 are respectively arranged on both sides of the backplate 212. This layout makes the structure compact, the force system balanced, and makes effective use of space. Since the backplate 212 is directly connected to the vehicle body 11, the push rod motor 27 can be placed inside the vehicle body 11.

[0066] The traction shaft 26 is a key moving component that directly performs the locking function. Its structure includes a vertically extending main shaft 263, an annular detection plate 262 fixedly mounted on the main shaft 263, and an abutment cover 261 located at the top of the main shaft.

[0067] To ensure the straightness and smoothness of the vertical movement of the traction shaft 26 and to prevent jamming or skew, a guide cylinder 213 is specially provided on the base 21. The lower end of the traction shaft 26 passes precisely through this guide cylinder 213, and a precise fit clearance is maintained between the inner wall of the guide cylinder 213 and the traction shaft 26, providing reliable constraint and guidance for the reciprocating movement of the traction shaft 26.

[0068] In this embodiment, the elastic element 24 is preferably a helical compression spring. This spring is sleeved on the outside of the main shaft 263 of the traction shaft 26, with its upper end abutting against the lower surface of the detection piece 262 and its lower end abutting against the base 21. In its natural state, the preload of the elastic element 24 continuously acts upward on the detection piece 262, thereby driving the entire traction shaft 26 upward, causing its bottom end to retract and move away from the shaft receiving hole 22. At this time, the connecting device is in its normal unlocked state, providing the necessary power source for the automatic separation function.

[0069] The push rod motor 27 is the main power source of this solution, preferably a push rod motor. Its core function is to provide power for the locking process. The output end of the push rod motor 27 is connected to a push rod 251. The middle part of the push rod 251 is connected to the base 21 via a hinge shaft, thus forming a lever mechanism. One end of the push rod 251 is connected to the output end of the push rod motor 27, which is the power input end; the other end is kept in contact with the abutment cover 261 at the top of the traction shaft 26 via a roller 252.

[0070] This lever structure can effectively amplify the driving torque output by the push rod motor 27, which means that the locking action can be completed using a drive unit with less power and lower cost, reducing system energy consumption and making motion transmission smoother and more controllable.

[0071] The roller 252 added between the push rod 251 and the contact cover 261 transforms the original sliding friction into rolling friction. This significantly reduces the frictional resistance and wear between the contact points, which not only further reduces drive energy consumption but also reduces operating noise and extends the service life of the push rod 251 and the contact cover 261.

[0072] The status detection component is a crucial element in ensuring the safe and reliable operation of the system. It comprises a lower detector 231 and an upper detector 232 fixedly mounted on the base 21, and an annular detection plate 262 that moves in conjunction with the traction shaft 26. Both the lower detector 231 and the upper detector 232 are preferably contact sensors, positioned at different heights in the vertical direction. The detection plate 262 moves synchronously with the traction shaft 26. When it reaches the height of the lower detector 231, it triggers the lower detector 231, indicating that the traction shaft 26 has descended to the locked position; when it reaches the height of the upper detector 232, it triggers the upper detector 232, indicating that the traction shaft 26 has ascended to the unlocked position.

[0073] This mechanism, which directly detects the position of moving parts, can provide real-time and accurate feedback to the control system on the actual status of the connected device, locking or unlocking it, thus providing a reliable basis for status judgment throughout the automation process. Compared to non-contact sensors, contact sensors have stronger resistance to electromagnetic interference, stable and reliable signals, and are suitable for the complex electromagnetic environment of industrial sites.

[0074] The workflow of this technical solution is as follows:

[0075] First, the initial and unlocked states.

[0076] Under normal conditions where the traction robot is not performing connection operations, the connection device 2 remains stably in the unlocked state. At this time, the push rod motor 27 is not started, and the restoring force of the elastic element 24 is fully released, pushing the detection piece 262 upward, thereby driving the traction shaft 26 to move upward along the guide cylinder 213, so that its bottom end is completely retracted from the shaft hole 22.

[0077] Simultaneously, the detection plate 262 rises to trigger the upper detector 232, and the control system receives a clear unlocking status signal. This ensures that the robot will never accidentally become entangled with the material cart while moving or in standby mode, improving the inherent safety of the equipment operation. The guide cylinder 213 ensures the straightness of the traction shaft 26's movement during this process, avoiding jamming or additional wear caused by skewness.

[0078] Then, the automatic locking process begins.

[0079] When the control system instructs the robot to connect with the material cart, the push rod motor 27 starts and outputs thrust. The thrust is amplified and reversed by the push rod 251 of the lever structure, and then converted into downward pressure on the contact cover 261 via the roller 252. This pressure is sufficient to overcome the elasticity of the elastic element 24, and push the traction shaft 26 to overcome friction and move smoothly downward along the guide cylinder 213.

[0080] As the traction shaft 26 continues to descend, its bottom end eventually inserts precisely into the pin hole of the material cart connecting plate, corresponding to the shaft receiving hole 22, thus achieving physical locking.

[0081] When the traction shaft 26 moves to the lowest point, the detection plate 262 triggers the lower detector 231, which sends a lock success signal to the control system. Then the traction robot operates normally and performs the transport task.

[0082] The entire locking process is completed autonomously without any human intervention. It is not only far more efficient than manually inserting and removing pins, but also completely eliminates the safety risks associated with personnel entering the work area.

[0083] Finally, the automatic unlocking process.

[0084] When the handling task is completed and the robot needs to be separated from the material cart, the control system only needs to control the push rod motor 27 to reset and retract the push rod 251. Once the pressure of the push rod 251 on the contact cover 261 is released, the elastic element 24, which has been in a compressed and stored energy state, immediately releases its elastic potential energy, quickly and reliably pushing the traction shaft 26 upward back to the initial unlocked position. The detection plate 262 then triggers the upper detector 232 to confirm that the unlocking is complete.

[0085] In summary, the connecting device and traction robot provided in this embodiment, through the synergistic effect of the push rod motor 27 and the elastic element 24, eliminate the reliance on manual operation in existing technologies, and achieve improvements in efficiency, safety, and reliability, meeting the requirements of modern industrial intelligent logistics for high-performance equipment.

[0086] In this embodiment, the push rod 251 is on top, and the elastic element 24 and traction shaft 26 are below. Engineers can arrange them in different spatial structures based on the above principles. For example, the push rod 251 can be below, or the push rod 251 and elastic element 24 can be arranged horizontally or at an angle. As long as the direction of movement and the direction of force supply of the push rod 251 are opposite to the direction of the elastic force of the elastic element 24, it is acceptable.

[0087] The precise positioning function and safety status identification function of the present invention will be described in detail below.

[0088] The positioning module of the control system is a key component that ensures the traction robot performs connection or separation operations within a designated area. It achieves high-precision and high-reliability position determination through a dual verification mechanism combining absolute and relative positioning.

[0089] The positioning module includes a tag reading module, such as an RFID reader or a QR code scanner, and a distance calculation module, integrated into a microcontroller or PLC. The following details the process step-by-step.

[0090] Figure 4 The diagram shows the trajectory of the traction robot, visually illustrating the positional relationship between the pre-target point and the target point during the localization process. The robot starts from the starting point, passes the pre-target point, and then reaches the target point through distance calculation and tag reading. Figure 4 The arrows in the diagram indicate the normal direction of travel for the traction robot. Point A is the final target point, and A0 is the preliminary target point. In reverse mode, point D is the final target point, and D0 is the preliminary target point.

[0091] The principles of moving from point A to point D are the same; the following example will use point A.

[0092] Step 1: Approach point A0.

[0093] The robot travels along a preset path, approaching the target point. The tag reading module, using an RFID reader or an industrial-grade QR code camera, is mounted on the front or side of the vehicle body 11 to identify tags deployed on the ground or in the environment. RFID tags require no power, have strong anti-interference capabilities, and are suitable for industrial environments; QR code cameras can enhance recognition rates through image processing algorithms, avoiding misreading.

[0094] When the robot approaches the target point, the tag reading module scans the environment and reads the ID of the pre-A0 tag. Upon successful reading, the module outputs a digital signal to the control system.

[0095] Assume the pre-target point A0 label is set 3 meters away from the target point on the path. The robot travels at a speed of v = 0.5 m / s. When the label reading module detects the pre-target point A0 label, the system records this moment t0 = 0 seconds and triggers the distance calculation module to start working.

[0096] Pre-alignment serves as an initial positioning step, reducing the robot's reliance on single target point labels. If a pre-target point label is not read, the system can issue an early warning, preventing the robot from overtraveling and saving time and energy. This step improves the robustness of the positioning process and lays the foundation for subsequent accurate alignment.

[0097] Step 2: Distance calculation.

[0098] The distance calculation module is integrated into the robot's main control unit, such as an ARM microcontroller or industrial PLC, and calculates the distance by receiving pulse signals from an encoder or speed sensor. The encoder is mounted on the drive wheel of the walking device 14. The module collects the traveling speed v and the elapsed time t in real time and calculates the traveling distance d = v × t. The calculation formula is based on the assumption of uniform speed; if the speed fluctuates, the accuracy can be improved by using an integral algorithm.

[0099] The preset travel distance threshold d1 = 1.5 meters. That is, the distance between point A0 and point A is 1.5 meters. The robot travels from the pre-target point at a constant speed of v = 0.5 m / s. After t = 3 seconds, d = 0.5 × 3 = 1.5 meters, reaching d1. If the speed is not constant, such as v varying between 0.4 and 0.6 m / s, the module calculates d using an accumulated pulse count matching integral algorithm to ensure accuracy.

[0100] In different embodiments, the specific calculation method for the travel distance d varies. For example, in some embodiments, the travel distance d can be calculated based on the number of wheel rotations n and the wheel radius r. The circumference, i.e., the distance traveled in one revolution, can be obtained from the wheel radius r, and the travel distance d can be obtained from the number of rotations n.

[0101] Distance calculation, as a relative positioning method, compensates for the cumulative errors of absolute tag positioning, such as tag installation deviations. Dual verification avoids premature stopping due to tag misreading, such as dust obstruction, thus improving positioning reliability.

[0102] Step 3: Formal Positioning

[0103] When the travel distance d reaches the preset value d1 and the robot approaches the target point, the label reading module scans the environment again and reads the label of the target point A. At the same time, the distance calculation module verifies that d ≥ d1.

[0104] The positioning module determines that the robot has reached the target point and allows the connection / disconnection operation to be performed only when both conditions are met simultaneously. Formal alignment ensures that operations are only performed within a safe area, avoiding accidental triggering along the path. For example, in a warehouse, the target point may be located in front of a shelf; dual verification prevents the robot from colliding with the shelf due to damaged tags, improving system safety and automation.

[0105] In some embodiments, engineers can implement a more relaxed design. That is, if the pre-target point A0 has been successfully read and the distance calculation module verifies that d ≥ d1, then even if the target point A label is not read, it is considered that the target point has been successfully reached. This is because the target point A label may be damaged. In this case, the robot can still work normally, but it sends this information to the control system so that the control system can check and replace the target point label.

[0106] Safety status identification is a core feature ensuring the safe execution of connection or disconnection operations by the traction robot. For example... Figure 5 As shown, it achieves automated identification of locked, unlocked, and fault states through the coordinated operation of the height detection module 102 and the current reading module 101, combined with the logical judgment of the identification module 103. This dual detection scheme abandons the traditional method of relying on a single signal, improving the reliability and security of the system, which will be described in detail below.

[0107] Figure 3 The detailed structure of the connecting device 2 is shown, including the components of the height detection module, the lower detector 231 and the upper detector 232, and the push rod motor 27. This figure visually illustrates the positional relationship between the detection piece 262 and the sensor, providing the hardware foundation for state identification.

[0108] S01. Parking Procedure;

[0109] The traction robot reaches the target point and stops moving.

[0110] S02, Data reading steps: Real-time reading of current value I and height value H.

[0111] For example, the current reading module 101 can be implemented in hardware using a Hall effect current sensor integrated into the power supply circuit of the push rod motor 27. This sensor converts changes in the magnetic field into a current signal. The sampling frequency can be set to 100Hz to ensure real-time performance.

[0112] The height detection module 102 includes two contact sensors in hardware: a lower detector 231 and an upper detector 232, which are fixed at specific height positions on the base 21. The sensors are preferably microswitches or limit switches. When the detection piece 262 is triggered by the movement of the traction shaft 26, it outputs a switching signal, such as a high level indicating triggering and a low level indicating no triggering.

[0113] In this case, the height value H is represented by a combination of sensor states: for example, when the lower detector 231 is triggered, H is defined as the low bit (H < H1), when the upper detector 232 is triggered, H is defined as the high bit (H > H2), and when neither is triggered, H is in an intermediate state.

[0114] For example, the current I of the push rod motor 27 is about 0.3A when unloaded, and rises to 2.5A during the locking process due to the increased load.

[0115] H1 and H2 are preset to 2mm and 48mm respectively. Therefore, the installation position of the lower detector 231 is slightly lower than H1, for example, 0mm, and the installation position of the upper detector 232 is slightly higher than H2, for example, 50mm. That is, when the traction shaft 26 moves downward to trigger the lower detector 231, H=0mm; when it moves upward to trigger the upper detector 232, H=50mm.

[0116] Hall effect sensors offer non-contact measurement, avoiding circuit interference; contact sensors provide strong resistance to electromagnetic interference and stable signals. Low data acquisition latency meets real-time industrial requirements. Dual data sources provide redundancy. For example, if a height sensor fails due to mechanical jamming, the current signal can still indirectly reflect the state change, reducing the risk of single-point failure. Real-time acquisition ensures the system can respond promptly to changes in operating conditions, laying the foundation for accurate identification.

[0117] In some embodiments, instead of using the above-described up and down detector scheme, a laser rangefinder sensor can be used, which is installed on the traction shaft 26 to obtain its ground clearance H in real time and compare it with H1 and H2 in the system.

[0118] S03, State Judgment Step: The identification module 103 outputs the state result based on logical conditions.

[0119] The identification module 103 is integrated into the robot's main control unit, such as an STM32 microcontroller, and implements state machine logic through software algorithms. The algorithm continuously monitors the current value I and the height value H, and compares them with preset thresholds. The judgment logic is as follows:

[0120] When I > the first current threshold I1 and H < the first height threshold H1, the lockout is identified as complete.

[0121] When I < the second current threshold I2 and H > the second height threshold H2, it is identified as the unlocking completed state.

[0122] If the signals are contradictory, such as I being abnormally high but H not changing, then a fault condition is identified and an alarm is triggered.

[0123] For example, the threshold settings can be based on experimental calibration: I1 is set to 2A, indicating that the motor overcomes the load of the spring element 24. I2 is set to 0.5A, indicating that the motor is unloaded; H1 and H2 are fixed by the sensor mounting position.

[0124] During the locking process, relying solely on the current signal may lead to a false alarm due to increased current caused by external resistance, such as mechanical jamming or interference from foreign objects, when in reality the traction shaft is not fully in position, resulting in a false engagement risk. Similarly, during the unlocking process, relying solely on the height signal may result in incomplete traction shaft reset due to spring failure or mechanical wear. Although the height detection indicates the unlocked position, residual connection may still exist, creating a false unlocking risk.

[0125] By integrating a dual verification mechanism of current and height, the system only confirms the state transition when both current exceeds the threshold and height are reached simultaneously during locking; and when unlocking, both current unloading and height reset are required. This fundamentally eliminates the two dangerous operating conditions of false engagement and false disengagement, ensuring the reliability of each state transition and the safety of the system.

[0126] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Furthermore, the terms "vertical," "horizontal," "front," and "rear," etc., mentioned in the embodiments of the present invention indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should be further noted that, unless otherwise explicitly specified and limited, terms such as "install," "connect," "join," and "fix" in the description should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0127] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A control system for a traction robot, comprising a connecting device (2) for connecting to a material cart, said connecting device (2) comprising a base (21) and a traction shaft (26) movably connected to said base (21); characterized in that: The connecting device (2) also includes a spring element (24) and a push rod motor (27). The elastic element (24) is configured to drive the traction shaft (26) into an unlocked state; the push rod motor (27) is configured to drive the traction shaft (26) to move, causing the traction shaft (26) to overcome the elastic force of the elastic element (24) and enter a locked state. The control system also includes a current reading module, a height detection module, and an identification module; The current reading module is configured to read the current value I of the push rod motor (27); The height detection module is configured to read the height value H of the traction shaft (26); The identification module is configured to determine the connection status based on the current value I and the height value H.

2. The control system for a traction robot according to claim 1, characterized in that: When the current value I is greater than the preset first current threshold I1, and the height value H is lower than the preset first height threshold H1, the identification module determines that the current state is the locking completion state.

3. The control system for a traction robot according to claim 2, characterized in that: When the current value I is less than the preset second current threshold I2, and the height value H is higher than the preset second height threshold H2, the identification module determines that the current state is the unlocking completed state.

4. The control system for a traction robot according to claim 1, characterized in that: It also includes a positioning module, which includes a tag reading module for reading environmental tags. The positioning module is configured to determine whether a target point has been reached by reading the target point tag, and after reaching the target point, allow the push rod motor (27) to drive the traction shaft (26) to move.

5. The control system for a traction robot according to claim 4, characterized in that: The positioning module also includes a distance calculation module; The label reading module reads the labels of the pre-target points; The distance calculation module is configured to calculate the distance d that the robot travels after reaching the pre-target point; The positioning module is configured to determine that the target point has been reached only when the travel distance d reaches a preset value d1 and the tag reading module reads the target point tag.

6. The control system for a traction robot according to claim 5, characterized in that: The distance calculation module calculates the travel distance d based on the traction robot's travel speed v and the time t elapsed after reaching the target point.

7. The control system for a traction robot according to any one of claims 1-6, characterized in that: The height detection module includes a lower detector (231) and an upper detector (232) set at different height positions on the base (21). The lower detector (231) and the upper detector (232) are used to detect the height position of the traction shaft (26).

8. The control system for a traction robot according to claim 7, characterized in that: The traction shaft (26) includes a vertically extending main shaft (263) and a detection piece (262) disposed on the main shaft (263). The detection piece (262) is an annular detection piece that protrudes outward from the main shaft (263). Both the lower detector (231) and the upper detector (232) are contact sensors.

9. The control method for a control system suitable for a traction robot according to any one of claims 1-8, characterized in that, It includes the following steps: S01. Parking Procedure; The towing robot reaches the target point and stops moving. S02, Data Reading Steps; The height detection module reads the height value H of the traction shaft (26). The current reading module reads the current value I of the push rod motor (27); S03, Status Judgment Steps; The separate module determines the connection status based on the current value I and the height value H.

10. The control method for a control system suitable for a traction robot according to claim 9, characterized in that: Prior to step S01, there is a pre-positioning step: Before reaching the target point, the arrival at the target point is determined by reading the pre-target point label; The robot determines whether it has reached the target point based on the distance traveled d after reaching the pre-target point and the target point label read.

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