An automatic foot bath robot and intelligent control method

Abstract

The application discloses an automatic foot bath robot and an intelligent control method, and belongs to the field of intelligent physiotherapy robots.The foot bath robot comprises a foot bath host, a mother port docking base station and a radio frequency positioning remote controller.The foot bath host is integrated with a front drive and a rear follow-up walking chassis, an independent drainage waterway, a constant-temperature massage module and a double-main-control linkage control system.The mother port base station is provided with an arch-shaped concave docking cavity, an elastic limiting correction mechanism and a separated water inlet and drainage pipeline.The radio frequency remote controller realizes wireless fixed-point navigation.The application discloses a radio frequency signal difference positioning scheme to reduce the hardware cost by abandoning the high-cost Mecanum wheel and a laser radar module of the prior art.The docking precision of the return flight is improved by relying on the elastic guide wheel correction.A water level and temperature linkage control and a fault self-diagnosis hierarchical protection mechanism are arranged to solve the safety defects of dry burning, water overflow, docking failure and sewage backflow.The whole machine can automatically complete the whole process operation of water adding, fixed-point moving foot bathing, automatic return drainage and charging, and manual water carrying is not needed, so that the application is suitable for home use of the old and the disabled, has simple structure, low production cost, high safety and reliability and high market promotion value.

Description

Technical Field

[0001] This invention belongs to the field of home intelligent physiotherapy robot technology, specifically involving a fully automatic foot bath robot that can autonomously complete automatic water addition, fixed-point mobile constant temperature foot bath, automatic return to drain water, and autonomous charging. It is suitable for home foot health care and elderly rehabilitation physiotherapy scenarios. Background Technology

[0002] Foot baths, which involve soaking the feet in warm water and massaging the soles to stimulate acupoints, can promote blood circulation and relieve physical fatigue. They are a widely used home health care device. However, traditional fixed foot bath basins require manual handling, water filling, and wastewater emptying, making them very inaccessible to the elderly and those undergoing rehabilitation.

[0003] Existing portable foot bath equipment falls into two categories: The first type is a simple roller foot bath, which is only equipped with passive rollers and has no autonomous walking or automatic water filling and drainage structure. It still needs to be moved manually and has a very low level of intelligence. The second category is the prior invention patent CN113181025A, "An Intelligent Foot Bath Robot." This solution discloses an autonomous mobile foot bath robot with an integrated charging station, which can achieve autonomous movement, water addition, and self-cleaning functions. However, it has several substantial defects that make it difficult to implement in practice: (1) The mobile chassis adopts the Mecanum wheel + LiDAR SLAM mapping scheme, which has high driving and sensing hardware costs, complex whole machine molds, high price threshold for ordinary households, and difficulty in large-scale popularization; (2) The whole machine relies solely on preset indoor coordinates for navigation and lacks a portable handheld positioning terminal. Users cannot flexibly change the foot bath location in real time, thus limiting its applicability to various scenarios. (3) The water channel and charging docking have no mechanical limit correction structure, which makes the water channel and electrode misalignment easy to occur when the robot returns, resulting in frequent water leakage and poor charging contact. (4) The water inlet, drainage, temperature control and walking control are independent logics, without a linkage closed-loop control strategy. There is no graded protection mechanism when the water level or water temperature is abnormal, which poses a safety hazard of dry burning and overflow. (5) Lack of whole machine fault self-diagnosis, fault level shutdown protection, and abnormal alarm logic, which may lead to safety risks when the equipment leaks water, the motor is stuck, or the battery is depleted. (6) The water circuit has no independent control solenoid valve. Water supply and drainage share the same pipeline, which can easily cause sewage backflow and contaminate the clean water pipeline, resulting in poor hygiene.

[0004] Currently, the market lacks a fully automatic foot bath robot that combines low-cost hardware structure, flexible fixed-point navigation, high-precision automatic docking, intelligent control throughout the entire process, and multiple safety protections. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technology CN113181025A, such as high cost, poor navigation flexibility, low docking accuracy, lack of linkage safety control, and lack of fault self-diagnosis. This invention provides an automatic foot bath robot. On the one hand, it simplifies the hardware structure of the walking chassis to reduce production costs. On the other hand, it adds a radio frequency handheld positioning remote controller, a mechanical limit correction structure, a multi-module linkage control algorithm, and a fault self-diagnosis system to achieve full automation of the process of adding water, moving, constant temperature massage, returning to base for drainage, and charging. At the same time, it solves safety and usage defects such as overflow, dry burning, docking failure, and sewage backflow. Technical solution

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an automatic foot bath robot and intelligent control method, characterized in that it includes a foot bath host, a home port docking base station, and a radio frequency positioning remote controller; The foot bath host can be detachably and sealedly connected to the mother port docking base station. The mother port docking base station is equipped with a remote control placement recess. The foot bath host integrates: an electric walking chassis system, an independent drainage water circuit control system, a battery charging docking module, a constant temperature heating massage system, a host main control unit, and a water level / water temperature / current acquisition and sensing module. The home port docking base station integrates: an automatic water inlet system, a base station charging docking electrode, a base station main control unit, a mains power transformer power supply module, and a return limit correction mechanism. The radio frequency positioning remote controller communicates wirelessly with the host main control unit to issue target positioning coordinates and working mode switching commands.

[0007] The integrated arch-shaped recessed docking cavity of the home port docking base station allows the foot bath unit to automatically fill with water, charge, and preheat. Once the water temperature and level are within acceptable limits, the unit detaches from the base station and autonomously navigates to the user's location based on the coordinates sent by the radio frequency positioning remote control. It maintains constant temperature throughout the process and activates foot massage. After the foot bath, the unit autonomously plans its return path and completes precise docking of the water path and electrodes through the limiting and correction mechanisms on both sides of the recessed cavity. After automatically draining the wastewater, it starts charging and enters sleep standby mode once fully charged.

[0008] As a further improvement to the present invention, the core subsystem structure is refined. (1) Electric walking chassis system The chassis adopts a front dual drive wheel + rear omnidirectional follower wheel layout. Two sets of walking motors are respectively installed on the left and right corners of the front side of the foot bath tub bottom, and omnidirectional follower wheels are installed on the two rear corners of the tub bottom. The main control unit outputs differential motor control signals, and steering is achieved through the differential speed of the left and right drive wheels. It abandons the high-cost Mecanum wheels and LiDAR, and only uses radio frequency positioning and navigation to achieve fixed-point walking, which greatly reduces hardware costs.

[0009] (2) Independent drainage water circuit control system for foot bath main unit An independent electromagnetic drain valve is fixed in the middle of the rear side of the bottom of the tub. The water inlet of the drain valve is connected to the inner cavity of the foot bath tub, and the drain outlet is exposed on the rear side of the tub. The main unit is equipped with a water level sensor to collect the liquid level in the tub in real time. It is linked with the heating module. When the water level is low, the heating power is automatically cut off to prevent dry burning. When the water level is high, the electromagnetic water inlet valve of the base station is controlled to stop water injection to prevent overflow.

[0010] (3) Charging docking module Metal female electrode connectors are arranged in pairs on both sides of the drain valve at the bottom of the tank, exposed on the rear side of the tank body; matching male electrode connectors are set inside the recessed cavity of the mother port; after returning to port, the electrodes automatically attach and conduct, realizing automatic charging without plugging or unplugging.

[0011] (4) Constant temperature heating massage system A PTC constant temperature heating block is installed in the middle of the front side of the bottom of the tub, and the built-in temperature sensor in the pipeline collects the water temperature in real time; multiple massage discs are set inside the tub, which are driven to rotate by a massage motor and a gearbox, and the main control unit of the main unit has built-in programs for multiple massage intensity and duration.

[0012] (5) Automatic water intake system of the home port An external water inlet is installed at the rear of the main port to connect to the tap water supply. The electromagnetic water inlet valve is connected to the built-in water inlet nozzle in the cavity through a water inlet hose. The water inlet electromagnetic valve is controlled by the base station main control unit in conjunction with the host water level sensor to automatically inject water in a quantitative manner. An independent drainage interface is set at the lower end of the main port, and an external drainage hose is connected to the sewer pipe to form a separate drainage path with the host electromagnetic drainage valve, so as to prevent sewage backflow and pollution of the clean water pipeline.

[0013] (6) Return limit correction mechanism The mother port recessed cavity is symmetrically equipped with elastic auxiliary guide wheels on both sides. When the main engine returns to the docking cavity, the guide wheels on both sides limit and correct the left and right movement of the main engine, correct the travel deviation, ensure the accurate alignment of the drain outlet and charging electrode, and solve the problems of misalignment, leakage and poor contact.

[0014] (7) Dual master control linkage control system The main control unit and the base station control unit exchange data bidirectionally via wireless communication; the main unit's built-in storage module stores navigation coordinates, massage programs, and fault codes; the base station control unit controls the electromagnetic water inlet valve and the transformer power output; the whole machine is equipped with multi-level safety protection logic.

[0015] Intelligent control methods: (1) Radio frequency positioning navigation control method The radio frequency positioning remote control transmits radio frequency positioning signals in real time. The radio frequency receiving modules on both sides of the main unit collect the signal strength difference. The main control unit calculates the relative offset based on the signal strength difference, dynamically adjusts the speed difference of the left and right drive wheels, continuously corrects the travel route, and accurately tracks the location of the remote control. No indoor pre-mapping is required, and it is compatible with any house type. (2) Closed-loop control method for water level and water temperature linkage The host water level sensor collects the liquid level signal, and the temperature sensor collects the water temperature signal, which are then synchronously transmitted to the host main controller. ① If the liquid level is below the safety threshold: immediately cut off the power supply to the PTC heating block and simultaneously issue a voice alarm to prevent dry burning; ② When the water level reaches the set foot bath level: a signal is sent to the base station main control to close the inlet solenoid water valve and stop water injection; ③ If the water temperature is lower than the set value: increase the PTC heating power; if the water temperature is higher than the set threshold: reduce the power or heat intermittently to maintain a constant temperature range.

[0016] (3) Return docking correction control method After receiving the end command, the host generates a return path and moves towards the home port base station. Before the host enters the concave cavity, the elastic wheels on both sides contact the barrel body to correct the lateral offset of the host. At the moment of contact between the electrode and the drain outlet, the host main control detects the electrode conduction signal and determines that the docking is complete, and starts the drainage and charging process in sequence. If the electrode fails to conduct for 3 consecutive docking attempts, the docking failure is determined, and a voice alarm prompts for manual alignment assistance. (4) Self-diagnosis and graded protection method for overall machine faults The main controller collects real-time signals of walking motor current, heating block operating current, battery voltage, water level, and electrode conduction status. ① Level 2 minor fault (low battery, slight water temperature fluctuation): voice prompts will not interrupt the foot bath process; ② Level 2 moderate fault (abnormal water level, slight motor stall): pause heating and massage, and automatically return to the base station; ③ Level 3 dangerous fault (dry burning risk, electrode short circuit, water leakage detection trigger): immediately cut off all power supply to heating, walking and charging, shut down and lock the whole machine, and continuously sound and light alarm.

[0017] The beneficial effects of this invention are: (1) Significantly reduced hardware costs: The simple walking chassis with front drive and rear follow-up is adopted, and radio frequency wireless positioning is used to replace the high-cost modules such as Mecanum wheels and LiDAR in the comparison document CN113181025A. The cost of mold and component procurement is reduced by more than 40%, which is suitable for promotion in the mass home market. (2) More flexible navigation: With a handheld radio frequency positioning remote control, users can change the foot bath position at will, and the robot will automatically follow and locate. There is no need to map the indoor area in advance, making it more adaptable to small apartments and multi-room scenarios. (3) Significantly improved docking reliability: The recessed cavity of the mother port is equipped with an elastic wheel limit correction mechanism to automatically correct the deviation of the main engine's return journey, solve the problems of water leakage and poor charging contact, and reduce the equipment failure rate; (4) Higher level of water hygiene and safety: The water inlet and outlet are completely separated and independent pipelines, equipped with independent water inlet and outlet solenoid valves to prevent the backflow of foot bath sewage and pollution of clean water pipelines; at the same time, water level and water temperature linkage protection is set to completely avoid the safety hazards of dry burning and overflow. (5) It has full-process intelligent linkage control capability: dual main controllers communicate in two directions to realize automatic linkage of the entire process of water injection, heating, movement, massage, return, drainage and charging without manual intervention; (6) Built-in fault self-diagnosis and graded protection system: Real-time monitoring of motor, heating, battery and water circuit status, graded alarm and graded shutdown, greatly improving the safety of equipment use and extending the service life of the whole machine; (7) Modular structural design, foot bath host, mother port base station and remote control are independently separated, making maintenance and parts replacement convenient, assembly process is simple, and it is conducive to industrial mass production. Attached Figure Description

[0018] Figure 1 Overall three-dimensional schematic diagram of the invention; Figure 2 Schematic diagram of foot bath unit and home port base station; Figure 3 Schematic diagram of the foot bath unit's bottom movement, water path, and charging structure; Figure 4 Schematic diagram of water ingress and power supply structure at the back of the base station in the home port; Figure 5 Schematic diagram of the longitudinal section structure of the entire machine (AA); Figure 6 Block diagram of the overall machine control logic framework.

[0019] Explanation of markings in the diagram: a-Foot bath main unit; b-Home port docking base station; c-Radio frequency positioning remote control; 10-Foot bath tub; 11-Upper control panel; 20-Walking motor; 21-Drive wheel; 30-Lithium battery pack; 40-Electromagnetic drain valve; 41-Drain outlet; 50-Electrode female connector; 60-PTC heating block; 70-Massage motor; 71-Gearbox; 72-Massage disc; 80-Universal caster wheel; 90-Main unit control unit; 91-Water level sensor; 92-Temperature sensor; 100-Mother port seat; 101-Recessed docking cavity; 200-Water inlet; 300-Solenoid water inlet valve; 301-External water inlet; 400-Water inlet hose; 401-Drainage hose; 500-Base station drainage interface; 600-Male docking electrode; 700-Transformer power supply; 800-Base station main control unit; 900-Elastic limit wheel. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] like Figures 1 to 5 As shown, an automatic foot bath robot and intelligent control method are disclosed, including a foot bath host a, a docking base station b, and a radio frequency positioning remote controller c; the upper end of the docking base station b has a recessed platform for placing the remote controller c, and the base station is integrally formed with an arch-shaped recessed docking cavity 101, in which the foot bath host a can be embedded to complete the water and electrical circuit sealing docking.

[0022] (1) Electric walking chassis The foot bath tub 10 has a walking motor 20 and a drive wheel 21 fixed at the two front corners of the bottom, and universal follower wheels 80 are installed at the two rear corners. The main control unit 90 outputs differential control signals, and achieves straight-line movement, turning, and fine-tuning in place by the speed difference between the left and right drive wheels. It works with the radio frequency positioning remote controller c to complete fixed-point tracking movement without the need for laser radar mapping.

[0023] (2) Foot bath main unit a water circuit and heating massage module An independent electromagnetic drain valve 40 is installed in the middle of the rear side of the bottom of the tub, and the drain outlet 41 is exposed on the rear side of the tub. A PTC heating block 60 is arranged on the front side of the bottom of the tub, and a temperature sensor 92 is built into the pipeline. The massage motor 70 inside the tub drives multiple massage discs 72 to rotate via a reduction gearbox 71. A water level sensor 91 is installed inside the tub to monitor the liquid level in real time. Electrode female connectors 50 are set in pairs on both sides of the electromagnetic drain valve 40 for connecting to the base station charging electrode.

[0024] (3) Home port base station b water inlet, calibration and power supply module The base station is connected to the electromagnetic water inlet valve 300 at the rear, and then to the water inlet nozzle 200 inside the cavity via the water inlet hose 400; the drainage interface 500 at the lower end of the base station is connected to the drainage hose 401 to the drain; elastic limit wheels 900 are symmetrically installed on the left and right sides of the recessed cavity; the base station is equipped with a transformer power supply 700 and a base station main control unit 800, and male and female electrodes 600 are arranged on the inner wall of the cavity.

[0025] (4) Dual-master communication architecture The main control unit 900 collects water level, water temperature, motor, and battery data, and wirelessly interacts with the base station main control unit 800; the main unit communicates with the radio frequency positioning remote controller c to receive positioning commands.

[0026] Overall Intelligent Control Workflow: Reference Figures 1 to 6 As shown, Step 1: Start the water injection and preheating stage The foot bath unit docks in the recessed docking cavity of the mother port, and the user starts the working program through the main unit / base station panel; the base station main control unit opens the electromagnetic water inlet valve, and tap water is injected into the foot bath tub; the water level sensor transmits the liquid level in real time, and automatically closes the water inlet valve after reaching the set value; the PTC heating block starts to heat up, and the temperature sensor controls the temperature in real time to maintain the preset foot bath water temperature.

[0027] Step 2: Radio Frequency Positioning Autonomous Movement Foot Bath Stage Once the water temperature reaches the target, the main unit drives the walking motor to detach from the base station; the radio frequency positioning remote control continuously sends positioning signals, and the radio frequency receiving modules on both sides of the main unit collect the signal strength difference. The main control dynamically adjusts the speed difference between the left and right drive wheels to continuously correct the route and track the user's location; after reaching the target point, the main unit automatically stops, continues to heat at a constant temperature, and simultaneously starts the foot massage program, supporting multiple levels of intensity and duration customization.

[0028] Step 3: Automatic return-to-home calibration and docking phase When the user finishes the foot bath, they issue a return command; the host autonomously plans a path to return to the home port base station; when the host enters the recessed docking cavity, the elastic wheels on both sides laterally correct the barrel's offset, ensuring precise alignment of the drain outlet and charging electrodes; after the electrodes are connected, the host determines that the docking is complete and opens the electromagnetic drain valve to empty the wastewater in the barrel.

[0029] Step 4: Automatic charging standby stage After the wastewater is discharged, the base station transformer outputs safe low-voltage DC power to charge the host lithium battery pack through the docking electrode; the main controller monitors the battery voltage in real time, and cuts off the charging circuit after the battery is fully charged, and the whole machine enters sleep standby mode.

[0030] Fault self-diagnosis implementation example The main control unit collects all electrical and sensor signals in real time: (1) When the water level is low, immediately cut off the power supply to the PTC heater and announce "Insufficient water level, please add water"; (2) The walking motor stalls due to abnormal current, automatically stops and returns to the base station, displaying the message "walking mechanism failure"; (3) If the electrodes fail to conduct for 3 consecutive times, it is determined that the docking is misaligned, and an audible and visual alarm prompts manual realignment. (4) If the battery voltage is lower than the protection threshold, long-distance travel is prohibited, and the battery must be forced to return to the charging station for charging. (5) If the temperature exceeds the safety limit, the heating module will be cut off and the whole machine will be shut down for protection.

[0031] Radio frequency positioning navigation examples The radio frequency positioning remote control has a built-in radio frequency transmitting module, and radio frequency receiving antennas are symmetrically arranged on the left and right sides of the main unit. The main control unit compares the difference in signal strength received by the two antennas and calculates the offset direction and distance of the main unit relative to the remote control. If the signal on the left is stronger, the speed of the left drive wheel is increased and the speed of the right wheel is decreased to correct the travel route to the right. This process is iterated until the signal strength difference approaches zero, thus achieving precise point tracking.

Claims

1. An automatic foot bath robot and its intelligent control method, characterized in that: Includes foot bath main unit, home port docking base station, and radio frequency positioning remote control; The foot bath host and the home port docking base station can be detachably sealed with water and electrical circuits. The upper end of the home port docking base station is provided with a placement recess for placing the radio frequency positioning remote controller. The foot bath host is equipped with an electric walking chassis system, an independent drainage water circuit control system, a battery charging docking module, a constant temperature heating massage system, a host main control unit, a water level acquisition sensor, and a water temperature acquisition sensor. The home port docking base station is equipped with an automatic water inlet system, a base station charging docking electrode, a base station main control unit, a mains power transformer power supply module, and a return limit correction mechanism. The radio frequency positioning remote controller establishes wireless radio frequency communication with the host main control unit to send target positioning coordinates and working mode switching instructions. The integrated arch-shaped recessed docking cavity of the home port docking base station allows the foot bath unit to dock in the recessed docking cavity to complete automatic water filling, charging, and preheating. After the water temperature and level reach the standard, the foot bath unit detaches from the home port docking base station and autonomously navigates to the user's location for constant temperature massage based on the positioning signal of the radio frequency positioning remote control. After the foot bath is completed, the foot bath unit autonomously returns to its home port and completes precise docking of the water circuit and electrodes through the return limit correction mechanism. It then automatically drains the wastewater and starts charging. Once fully charged, the entire unit enters sleep standby mode.

2. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The electric walking chassis system includes two sets of walking motors, drive wheels, and two omnidirectional follower wheels; the two sets of walking motors are fixedly installed on the left and right corners of the front side of the bottom of the foot bath tub, and the omnidirectional follower wheels are installed on the left and right corners of the rear side of the bottom of the foot bath tub; the main control unit of the host outputs differential control signals to adjust the speed difference between the two sets of walking motors to achieve steering and route correction.

3. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The independent drainage water circuit control system includes an electromagnetic drain valve, which is fixed to the middle of the rear side of the bottom of the foot bath tub. The water inlet of the electromagnetic drain valve is connected to the inner cavity of the foot bath tub, and the drain outlet is exposed on the rear side of the tub. The water level acquisition sensor is linked with the main control unit of the host computer. When the water level is low, the heating power supply is automatically cut off. When the water level is high, a water stop signal is sent to the main control unit of the base station.

4. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The battery charging docking module includes a lithium battery pack and a pair of female electrode connectors. The lithium battery pack is installed at the bottom of the foot bath tub, and the female electrode connectors are arranged in pairs on both sides of the electromagnetic drain valve and exposed on the rear side of the tub body for contact and communication with the charging electrodes of the home port base station.

5. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The constant temperature heating massage system includes a PTC heating block, a massage motor, a gearbox, and multiple massage discs; the PTC heating block is fixed in the middle of the front side of the bottom of the tub, and the water temperature sensor collects the water temperature to achieve constant temperature regulation; the massage motor drives the massage discs inside the tub to rotate via the gearbox.

6. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The automatic water inlet system of the home port docking base station includes an electromagnetic water inlet valve, a water inlet hose, and a built-in water inlet nozzle; the electromagnetic water inlet valve is connected to tap water and is connected to the water inlet nozzle in the recessed docking cavity through the water inlet hose; an independent drainage interface is set at the lower end of the base station, and an external drainage hose is connected to the sewer pipe, and the water inlet and drainage pipes are isolated from each other.

7. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The return-to-home limiting correction mechanism consists of elastic limiting wheels symmetrically installed on the left and right sides of the concave docking cavity. The elastic limiting wheels are used for lateral limiting when the foot bath host returns to home, correcting walking deviation and ensuring precise alignment of the drain outlet and charging electrode.

8. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The host main control unit and the base station main control unit communicate wirelessly in two directions to exchange water level, water temperature and electrode conduction status data; the host main control unit has a built-in fault self-diagnosis program, collects motor, heating and battery sensor signals in real time, and executes alarm and shutdown protection actions in stages.

9. The automatic foot bath robot and intelligent control method according to claim 1, characterized in that: The radio frequency positioning remote control has a built-in radio frequency transmitting module, and radio frequency receiving antennas are symmetrically arranged on the left and right sides of the foot bath host. The host main control unit compares the difference in the signal strength received by the two antennas, dynamically adjusts the speed difference of the walking motor to correct the travel route, and tracks the position of the radio frequency positioning remote control.

10. An automatic foot bath robot and intelligent control method based on any one of claims 1 to 9: characterized in that, Includes the following steps: S1 Standby Water Injection and Preheating Steps: The foot bath main unit docks in the recessed docking cavity of the mother port, the base station main control opens the electromagnetic water inlet valve to inject water into the foot bath tub, the water level sensor transmits the liquid level signal back in real time, and the water automatically stops when the water level reaches the standard; the PTC heating block starts to heat up, and the water temperature sensor maintains a constant water temperature. S2 Radio Frequency Fixed-Point Mobile Foot Bath Procedure: After the water temperature reaches the target, the main unit disconnects from the base station. The radio frequency positioning remote control continuously transmits positioning signals. The main unit calculates the offset by the signal strength difference between the radio frequency antennas on both sides and dynamically adjusts the speed difference of the drive wheels to track the user's position. After reaching the point, it maintains a constant temperature and starts foot massage. S3 Return and Correction Docking Procedure: After receiving the foot bath end command, the main unit returns autonomously. When entering the concave docking cavity, the elastic limit wheels on both sides correct the barrel body offset, and the drain outlet and charging electrode are sealed and docked. After the electrodes are connected, the electromagnetic drain valve is opened to drain the wastewater. S4 Automatic Charging Standby Procedure: After the wastewater is drained, the base station transformer power supply charges the lithium battery pack through the docking electrode. Once the battery is fully charged, the charging circuit is cut off, and the entire device enters sleep standby mode. S5 Fault Self-Diagnosis and Graded Protection Steps: The main controller collects water level, water temperature, motor current, battery voltage, and electrode continuity signals in real time, and performs graded protection measures such as voice prompts, work stoppage, complete machine shutdown and lockout, and audible and visual alarms according to the fault level.

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