Wheel-leg combined multi-mode robot based on spherical tires and control method thereof

Abstract

The invention belongs to the technical field of robots, and particularly relates to a wheel-leg combined multi-mode robot based on spherical tires and a control method thereof.The bottom of a cargo storage box is provided with four wheel-leg mechanisms, the bottoms of the four wheel-leg mechanisms are rotationally connected with a tire frame, and the four wheel-leg mechanisms are provided with angle adjusting assemblies used for adjusting the overall angle of the tire frame; according to the robot, the obstacle crossing ability is remarkably improved, the spherical tire design is adopted, the wheel leg structure is combined, when the robot faces obstacles such as rocks and gullies, the posture and the tire angle can be flexibly adjusted, and the robot is high in practicability and high in practicability. The robot can move freely within the 360-degree range through the omni-directional moving capacity of the spherical tires, the robot can move forwards or backwards without changing the direction, and compared with a traditional wheeled robot, the adaptability and the obstacle crossing capacity of the robot in the complex terrain are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and in particular relates to a wheel-leg combined multi-modal robot based on spherical tires and a control method thereof. Background Art

[0002] The current situation of my country's mountainous and hilly land has brought great challenges to operations in many fields. In agriculture, the citrus industry, as one of my country's important industries, accounts for more than 1 / 3 of the world's output, and most of it is cultivated in hilly and mountainous areas. At present, in citrus production operations, harvesting accounts for about 40% of the total operation volume. However, traditional agricultural vehicles are difficult to use on hilly slopes, and new rail transportation equipment is too expensive to be popularized, which makes the automation of citrus harvesting and transportation an inevitable trend.

[0003] In mountainous operation scenarios, the application of robots is crucial. Existing mountain obstacle-crossing robots are mainly divided into three categories: wheeled, legged, and tracked. Wheeled robots usually use standard round tires, have a simple structure, and are composed of a chassis, wheels, and a drive system. They rely on wheel rotation to move quickly on flat ground, but in complex mountainous terrain, they have a large turning radius and poor obstacle-crossing capabilities. For example, the "Rover" series in the United States has limited adaptability to complex terrain. Legged robots imitate the movement of biological legs, are composed of multiple joints and servo motors, can climb slopes and cross obstacles through gait control, and have a high degree of freedom, but have low efficiency and high energy consumption on flat terrain. For example, Boston Dynamics' "BigDog" performs well in complex terrain, but its complex structure and control system lead to high maintenance and energy consumption costs. Tracked robots use a track system, including tracks, chassis and drive devices. They have good grip and stability and are suitable for soft or uneven ground. However, they have poor steering capabilities and limited movement in narrow spaces. For example, although "PackBot" is widely used in military and disaster relief fields, its flexibility and maneuverability in complex terrain are still insufficient.

[0004] In general, the existing mountain obstacle-crossing robots have their own advantages and disadvantages. There are common problems such as insufficient ability of wheeled robots to cross obstacles in complex terrain, high energy consumption and low mobility efficiency of legged robots, and poor maneuverability of tracked robots in narrow spaces. They are unable to meet the needs of complex terrain and diversified tasks in mountainous and hilly areas. This provides room for improvement for the wheel-leg combined multi-modal robot based on spherical tire design of the present invention. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a wheel-leg combined multi-modal robot based on spherical tires to solve the above-mentioned technical problems.

[0006] The solution adopted by the present invention is: a wheel-leg combined multi-modal robot based on a spherical tire, including a cargo storage box, four groups of wheel-leg mechanisms are provided at the bottom of the cargo storage box, the bottom of the four groups of wheel-leg mechanisms are rotatably connected to a tire frame, the four groups of wheel-leg mechanisms are provided with an angle adjustment component for adjusting the overall angle of the tire frame, the tire frame is rotatably connected to a spherical tire and a fixedly connected driving servo motor, and the spherical tire is driven by the driving servo motor.

[0007] Preferably, the wheel-leg mechanism includes a thigh arm hinged at the bottom of the cargo storage box, the thigh arm is hinged to a calf arm, the cargo storage box and the calf arm are both provided with a joint servo motor, and the thigh arm and the calf arm are both driven by the joint servo motor.

[0008] Preferably, the calf arm is rotationally connected to the tire frame, a large gear is fixedly connected to the rotating shaft, an angle servo motor is connected to the calf arm, and a small gear meshing with the large gear is connected to the output end of the angle servo motor.

[0009] Preferably, the thigh arm and the calf arm are both straight rod structures, and the connection parts between the joint servo motor and the thigh arm and the calf arm are provided with rubber shock-absorbing pads.

[0010] Preferably, an intelligent control system is also included, which integrates laser radar, camera, gyroscope and accelerometer sensors, and the scanning range of the laser radar can reach 360 degrees.

[0011] Preferably, a buffer device is provided at the thigh arm and calf arm joints, and the buffer device adopts a spring damper structure.

[0012] Preferably, a plurality of fixing straps and hooks are fixedly connected to the cargo storage box, the plurality of fixing straps and hooks are made of high-strength nylon material, and a buffer pad is provided inside the cargo storage box.

[0013] Preferably, the tire frame is provided with a plurality of LED lights and automatic sensing sensors.

[0014] Preferably, the drive servo motor and the joint servo motor are both provided with a waterproof sealed housing.

[0015] A multimodal motion control method based on the robot according to claim 8, comprising the following steps:

[0016] Terrain adaptive switching module: the laser radar collects terrain data in real time, combines the gyroscope attitude data, and the intelligent control system classifies the terrain through the fuzzy neural network algorithm of the accelerometer sensor;

[0017] Omnidirectional motion control module: controls the driving servo motor and uses a vector control algorithm to achieve three-dimensional motion of the spherical tire; based on Kalman filtering, it integrates the encoder and IMU data in the intelligent control system to achieve millimeter-level positioning;

[0018] Terrain compensation adjustment module: controls the angle servo motor to drive the tire frame to adjust the angle through the meshing of the large gear and the small gear;

[0019] Intelligent protection module: The joint buffer device absorbs impact energy in real time;

[0020] The pressure sensor in the cargo storage box monitors the cargo status;

[0021] The driving servo motor and joint servo motor protection system, the automatic sensing sensor is a temperature sensor or a humidity sensor;

[0022] Environmental interaction module: The ambient light sensor triggers the LED light to turn on automatically.

[0023] Preferably, in the terrain adaptive switching module, when it is detected that the height of the obstacle exceeds 30% of the radius of the spherical tire, the leg-type motion mode is triggered to control the joint servo motor to complete the leg-lifting-crossing-landing action sequence;

[0024] In the omnidirectional movement control module, when the turning radius of the spherical tire is less than the diameter of the spherical tire, the zero radius turning mode is started, and the 360° rotation is achieved by differentially controlling the four driving servo motors;

[0025] In the terrain compensation adjustment module, when the intelligent control system detects that the slope is greater than 25°, the graded compensation is started: first, the tire angle is adjusted to the maximum compensation position. If the stability requirement is still not met, the leg support assistance is triggered, which is achieved by controlling the joint servo motor in the above-mentioned vehicle.

[0026] In the intelligent protection module, when the accelerometer detects acceleration > 5g, emergency braking is triggered; when the pressure suddenly changes > the threshold, secondary buffering is started; when the temperature sensor detects temperature > 60°C or the humidity sensor detects humidity > 80% RH, heat dissipation or moisture-proof procedures are automatically started;

[0027] In the environmental interaction module, when the ultrasonic sensor detects an obstacle, it controls the LED light to adjust the illumination angle, and when the intelligent control system detects a pedestrian through a visual recognition algorithm, it triggers a directional flashing warning mode.

[0028] Beneficial effects:

[0029] 1. Significantly improved obstacle-crossing capability: The present invention adopts a spherical tire design, combined with a wheel-leg structure, so that the robot can flexibly adjust its posture and tire angle when facing complex terrain such as rocks, gullies and other obstacles, and effectively cross obstacles. The omnidirectional mobility of the spherical tire allows the robot to move freely within a 360-degree range and can move forward or backward without changing direction. Compared with traditional wheeled robots, it greatly improves the adaptability and obstacle-crossing capability in complex terrain.

[0030] 2. Enhanced flexibility and maneuverability: The omnidirectional mobility allows the robot to operate flexibly in narrow spaces and turn more agilely. In mountainous and hilly areas, the complex and changeable terrain environment requires the robot to be able to respond and adapt quickly. The robot of the present invention can easily shuttle through various small areas and perform tasks efficiently. For example, when performing transportation operations in citrus groves, it can more flexibly avoid trees and other obstacles.

[0031] 3. Improve task execution efficiency: The multimodal design enables the robot to automatically adjust its movement mode according to environmental changes and maintain high work efficiency in different terrains. Whether it is quickly transporting materials on relatively flat mountain roads or accurately crossing obstacles on rugged roads, the robot can quickly make the best choice, thereby improving the overall task execution efficiency, reducing operation time, and improving production benefits.

[0032] 4. Enhanced stability and reliability: The optimized mechanical structure, including the reasonable wheel-leg mechanism design, the setting of the buffer device and the stable cargo storage box structure, works together with the intelligent control system to make the robot more stable when operating in complex terrain. It reduces the failure rate caused by factors such as terrain bumps and impacts, improves reliability, and can be used stably for a long time in harsh environments, ensuring the continuity and safety of mountain operations.

[0033] 5. The multimodal motion control method of the present application realizes multi-dimensional and intelligent motion control for robots based on specific designs, significantly improves the adaptability, flexibility and stability of the robot in complex environments, effectively ensures the safety of the robot itself and the cargo it carries, and expands the application scenarios and practical value of the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is one of the perspective views of the stereogram of the present invention.

[0035] Figure 2 yes Figure 1 A partial enlarged view of .

[0036] Figure 3 yes Figure 1 A partial enlarged view of B.

[0037] Figure 4 yes Figure 1 A partial enlarged view of C.

[0038] Figure 5 It is a logic diagram of the control method of the present invention.

[0039] Figure 6 It is the logic diagram of the terrain adaptive switching module of the present invention.

[0040] Figure 7 It is the logic diagram of the omnidirectional mobile control module of the present invention.

[0041] Figure 8 It is the logic diagram of the terrain compensation adjustment module of the present invention.

[0042] Fig. 9 It is the logic diagram of the intelligent protection module of the present invention.

[0043] Fig.10 It is the logic diagram of the environment interaction module of the present invention.

[0044] Figure numerals: 1. cargo storage box; 2. tire frame; 3. spherical tire; 4. driving servo motor; 5. thigh arm; 6. calf arm; 7. joint servo motor; 8. large gear; 9. angle servo motor; 10. small gear. DETAILED DESCRIPTION

[0045] The above and other technical contents, features and effects of the present invention are described in detail below with reference to the attached Figure 1-10 The detailed description of the embodiments will clearly show that the structural contents mentioned in the following embodiments are all based on the drawings in the specification.

[0046] Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0047] Embodiment 1, a wheel-leg combined multi-modal robot based on a spherical tire, comprises a cargo storage box 1, wherein four groups of wheel-leg mechanisms are provided at the bottom of the cargo storage box 1, wherein the bottoms of the four groups of wheel-leg mechanisms are rotatably connected to a tire frame 2, wherein the four groups of wheel-leg mechanisms are provided with an angle adjustment assembly for adjusting the overall angle of the tire frame 2, wherein a spherical tire 3 and a fixedly connected driving servo motor 4 are rotatably connected to the tire frame 2, wherein the spherical tire 3 is driven by the driving servo motor 4.

[0048] As an alternative to Example 1, Figure 1 , 2 As shown, the wheel-leg mechanism includes: a thigh arm 5 is hinged at the bottom of the cargo storage box 1, and the thigh arm 5 is hinged to a calf arm 6. The cargo storage box 1 and the calf arm 6 are both provided with a joint servo motor 7, and the thigh arm 5 and the calf arm 6 are both driven by the joint servo motor 7.

[0049] As an alternative to Example 1, Figure 3 As shown, the calf arm 6 is rotationally connected to the tire frame 2, a large gear 8 is fixedly connected to its rotating shaft, an angle servo motor 9 is connected to the calf arm 6, and a small gear 10 meshing with the large gear 8 is connected to the output end of the angle servo motor 9.

[0050] As an alternative to Example 1, Figure 3 As shown, the thigh arm 5 and the calf arm 6 are both straight rod structures, and the connection parts between the joint servo motor 7 and the thigh arm 5 and the calf arm 6 are provided with rubber shock-absorbing pads.

[0051] As an alternative to Example 1, Figure 3 As shown, a buffer device is provided at the joints of the thigh arm 5 and the calf arm 6, and the buffer device adopts a spring damper structure.

[0052] Example 2, a wheel-leg combined multi-modal robot based on spherical tires also includes an intelligent control system. Based on Example 1, the system integrates laser radar, camera, gyroscope and accelerometer sensors, and the scanning range of the laser radar can reach 360 degrees.

[0053] As an alternative to Example 2, Figure 1 As shown, a plurality of fixing straps and hooks are fixedly connected to the cargo storage box 1 , and the plurality of fixing straps and hooks are made of high-strength nylon material. A buffer pad is provided inside the cargo storage box 1 .

[0054] As an alternative to Example 2, Figure 4 As shown, the tire frame 2 is provided with a plurality of LED lights and automatic sensing sensors.

[0055] As an optional solution of Embodiment 2, the driving servo motor 4 and the joint servo motor 7 are both provided with a waterproof sealed housing.

[0056] When using, Figure 1 As shown, first, four sets of wheel-leg mechanisms are installed on the bottom of the cargo storage box 1. The bottom of the cargo storage box 1 is pre-arranged with a connection portion hinged with the thigh arm 5. The thigh arm 5 is reliably connected to the cargo storage box 1 through high-strength bolts to ensure that the thigh arm 5 can flexibly rotate within a certain range. For the connection between the thigh arm 5 and the calf arm 6, suitable hinged components are also used to ensure smooth relative movement between the two, and a lubricating oil nozzle is installed at the hinge to allow lubricating oil to be added regularly to reduce wear.

[0057] like Figure 1 , 2As shown, when installing the joint servo motor 7 on the cargo storage box 1, first weld the customized metal bracket to the reinforcement rib at the bottom of the cargo storage box 1, the shape and size of the metal bracket match the shell of the joint servo motor 7, and then use bolts to fix the joint servo motor 7 to the metal bracket, so that the motor output shaft and the driving connection part of the thigh arm 5 are accurately aligned, and a reliable connection is achieved through the coupling to ensure the high efficiency of power transmission.

[0058] like Figure 2 As shown, when the joint servo motor 7 is installed on the calf arm 6, an adaptive mounting seat is designed according to the structure of the calf arm 6. The mounting seat is made of aluminum alloy and is fixed to the calf arm 6 by bolts. The joint servo motor 7 is installed on the mounting seat, and the motor output shaft is firmly connected to the driving connection part of the calf arm 6. A rubber shock-absorbing pad is installed between the motor and the calf arm 6. The shock-absorbing pad is glued to the connection part by strong glue to play a role in buffering and reducing vibration transmission.

[0059] The tire frame 2 is connected to the calf arm 6 through a rotating shaft. The rotating shaft is made of high-strength alloy steel to ensure sufficient strength and wear resistance. A sealed deep groove ball bearing is installed on the rotating shaft. The inner diameter of the bearing is tightly matched with the rotating shaft, and the outer diameter is fixed to the tire frame 2 through a pressure cover. The pressure cover is fastened by bolts to ensure that the tire frame 2 can rotate smoothly relative to the calf arm 6.

[0060] like Figure 3 As shown, the large gear 8 is installed on the rotating shaft and fixed to the rotating shaft by a key connection. The key is made of high-strength alloy material to ensure that the large gear 8 will not loosen during the rotation process. The small gear 10 is installed on the output shaft of the angle servo motor 9, also connected by a key, and a protective cover is installed on the outside of the small gear 10 to prevent foreign matter from entering the gear meshing part. The angle servo motor 9 is fixed by a mounting seat welded on the calf arm 6. The structural design of the mounting seat ensures that the output shaft and the large gear 8 are in the correct meshing position after the angle servo motor 9 is installed. The mounting seat is made of stainless steel and has good strength and corrosion resistance.

[0061] like Figure 4 As shown, the driving servo motor 4 is fixed to the tire frame 2 by bolts, and the output shaft of the driving servo motor 4 is connected to the driving connection part of the spherical tire 3 by a coupling. The coupling uses a rubber coupling with a certain elasticity, which can buffer the vibration of the motor output to a certain extent and ensure the effective transmission of power. The spherical tire 3 is installed in the bearing on the tire frame 2. The bearing uses a high-precision slewing bearing to ensure that the spherical tire 3 can rotate flexibly on the tire frame 2, and a sealing device is installed at the bearing to prevent dust, mud and sand from entering the bearing and affecting the rotation performance of the spherical tire 3.

[0062] Installation of intelligent control system: The control host of the intelligent control system is installed in a specially designed protective cabin inside the cargo storage box 1. The protective cabin is made of aluminum alloy and has good electromagnetic shielding and heat dissipation performance. The control host is fixed to the mounting bracket in the protective cabin by bolts. The mounting bracket is isolated from the bottom of the protective cabin by shock-absorbing rubber pads to reduce the impact of vibration on the control host.

[0063] The antenna of the wireless communication module is installed at a suitable position outside the cargo storage box 1. The antenna is connected to the control host through a coaxial cable. The length of the coaxial cable is reasonably selected according to the actual installation position, and the cable joint is waterproof and sealed to ensure the stability of signal transmission.

[0064] Sensor installation: The laser radar is installed on a lifting and rotating bracket on the top of the cargo storage box 1. The bracket adopts electric control mode, which can adjust the scanning height and angle range of the laser radar as needed. The laser radar is connected to the control host of the intelligent control system through a data cable. The data cable adopts a shielded cable to prevent electromagnetic interference from affecting the accuracy of data transmission.

[0065] The cameras are installed in the cargo storage box 1 in four directions: front, back, left and right. Each camera is fixed by an adjustable mounting bracket. The mounting bracket can adjust the shooting angle of the camera. The camera is connected to the control host through a video transmission line. The video transmission line also uses high-quality shielded wire to ensure clear and stable transmission of the video signal.

[0066] The gyroscope and accelerometer sensors are installed in the center of the cargo storage box 1 near the bottom and fixed by a dedicated mounting base. The mounting base is made of shock-absorbing materials to reduce the impact of vibration on the sensor measurement accuracy during the movement of the robot. The sensor is connected to the control host through a data cable. The data cable avoids strong power lines during wiring to prevent electromagnetic interference.

[0067] The buffer device of the spring damper structure is installed at the joint of the thigh arm 5 and the calf arm 6. The spring is sleeved on the joint connecting shaft and fixed at both ends by special spring seats. The spring seat is made of high-strength alloy steel and has an interference fit with the joint connecting shaft to ensure that the spring will not be displaced during operation. The damper is installed next to the spring seat. The piston rod of the damper is connected to the adjacent mechanical structure and fixed by bolts. The cylinder of the damper is fixed by a mounting bracket welded to the joint. The mounting bracket is made of aluminum alloy and has good strength and lightweight characteristics.

[0068] Installation of cargo storage box protection device: The fixing belt and hook on the cargo storage box 1 are fixed to the reinforcement plate inside the box by rivets. The reinforcement plate is made of thickened steel plate to improve the bearing capacity of the fixing belt and hook. The fixing belt is made of high-strength nylon braided belt with a width of 5 cm and a thickness of 0.5 cm, which has good tensile strength and wear resistance. The hook is made of stainless steel and the surface is chrome-plated to prevent rust.

[0069] The cushion inside the cargo storage box 1 is made of foam material and is glued to various surfaces inside the box with glue. The thickness is 8 cm. The shape of the cushion is customized according to the internal structure of the cargo storage box 1 to ensure that the cargo can be effectively protected from collision and vibration.

[0070] Installation of lighting and warning devices, LED lights and automatic sensing sensors: Multiple LED lights are evenly distributed and installed on the tire frame 2. The LED lights are fixed to the specially designed lamp holders by bolts. The lamp holders are made of aluminum alloy and have good heat dissipation performance. The power cord of the LED light is routed through the wire trough inside the tire frame 2 and connected to the power control module. The power cord uses waterproof insulated cables to ensure safe use in humid environments. The automatic sensing sensor is installed next to the LED light and fixed to the tire frame 2 by a bracket. The sensing surface of the sensor faces the front of the robot. The sensor is connected to the intelligent control system through a data cable, which is also waterproof. When the ambient light is lower than the set sensing sensitivity (such as 0.3 lux), the sensor sends a signal to the intelligent control system, and the control system automatically turns on the LED light.

[0071] Warning sign installation: A warning sign is pasted on the outer surface of the tire frame 2. The warning sign is made of reflective film material, and the reflective film is pasted on the tire frame 2 with strong glue to ensure firmness and reliability. The warning sign is in the shape of a triangle, with eye-catching yellow and black colors. It can reflect strong light under light, and the visible distance can reach 80 meters, effectively reminding surrounding people and vehicles to pay attention to the presence of the robot.

[0072] Installation of motor protection device and waterproof sealing housing: The waterproof sealing housing of the drive servo motor 4 and the joint servo motor 7 is made of engineering plastic material. The housing is divided into two parts, upper and lower parts, which are sealed by bolt connection. Rubber sealing rings are installed at the joints of the housing. The sealing ring is made of oil-resistant and aging-resistant rubber material to ensure good sealing performance. The lead-out wire of the motor is connected to the external power cord through a waterproof plug. The waterproof plug adopts a spiral connection method. A rubber sealing pad is installed between the plug and the socket, and a protective cover is installed on the outside of the plug to prevent dust and moisture from entering.

[0073] Motor heat dissipation optimization measures: Inside the waterproof sealed housing, heat sinks are set around the motor. The heat sinks are made of aluminum alloy and fit tightly to the motor housing through thermal conductive silicone to improve heat dissipation efficiency. At the same time, ventilation holes are designed on the housing. The ventilation holes adopt a maze structure to ensure air circulation and heat dissipation while preventing dust and moisture from entering. Dust screens are installed inside the ventilation holes and cleaned regularly to ensure good ventilation.

[0074] Example 3 (such as Figure 5-10 ): A multimodal motion control method based on the robot according to claim 8, comprising the following steps:

[0075] like Figure 6 As shown, the terrain adaptive switching module: the laser radar collects terrain data in real time, combines the gyroscope attitude data, and the intelligent control system classifies the terrain through the fuzzy neural network algorithm of the accelerometer sensor;

[0076] like Figure 7 As shown, the omnidirectional mobile control module: controls the driving servo motor 4, adopts the vector control algorithm to realize the three-dimensional movement of the spherical tire 3; based on the Kalman filter, the encoder and IMU data in the intelligent control system are integrated to realize millimeter-level positioning;

[0077] like Figure 8 As shown, the terrain compensation adjustment module controls the angle servo motor 9 to drive the tire frame 2 to adjust the angle through the engagement of the large gear 8 with the small gear 10;

[0078] like Fig. 9 As shown, the intelligent protection module: the joint buffer device absorbs the impact energy in real time;

[0079] The pressure sensor in the cargo storage box 1 monitors the cargo status;

[0080] The driving servo motor 4 and the joint servo motor 7 protection system, the automatic sensing sensor is a temperature sensor or a humidity sensor;

[0081] like Fig.10 As shown, the environmental interaction module: the ambient light sensor triggers the LED light to turn on automatically.

[0082] As an optional solution of Example 3, in the terrain adaptive switching module, when it is detected that the height of the obstacle exceeds 30% of the radius of the spherical tire 3, the leg movement mode is triggered to control the joint servo motor 7 to complete the leg lifting-crossing-landing action sequence;

[0083] In the omnidirectional movement control module, when the turning radius of the spherical tire 3 is less than the diameter of the spherical tire 3, the zero radius turning mode is started, and the four driving servo motors 4 are differentially controlled to achieve 360° rotation;

[0084] In the terrain compensation adjustment module, when the intelligent control system detects that the slope is greater than 25°, the graded compensation is started: first, the tire angle is adjusted to the maximum compensation position. If the stability requirement is still not met, the leg support assistance is triggered, which is achieved by controlling the joint servo motor 7;

[0085] In the intelligent protection module, when the accelerometer detects acceleration > 5g, emergency braking is triggered; when the pressure suddenly changes > the threshold, secondary buffering is started; when the temperature sensor detects temperature > 60°C or the humidity sensor detects humidity > 80% RH, heat dissipation or moisture-proof procedures are automatically started;

[0086] In the environmental interaction module, when the ultrasonic sensor detects an obstacle, it controls the LED light to adjust the illumination angle, and when the intelligent control system detects a pedestrian through a visual recognition algorithm, it triggers a directional flashing warning mode.

[0087] When using, refer to Figure 5-10 , Terrain Adaptive Switching Module ( Figure 6 ): In this module, the robot's intelligent control system uses laser radar and gyroscope to perceive the surrounding environment and its own posture. The laser radar has the ability to collect terrain data in real time and can accurately obtain three-dimensional information about the terrain around the robot. The gyroscope can provide the robot's posture data in real time, including tilt angle, rotation state, etc.

[0088] The intelligent control system integrates the terrain data collected by the lidar with the attitude data of the gyroscope, and uses the fuzzy neural network algorithm of the accelerometer sensor to classify the terrain. After being trained with a large amount of data, the algorithm can quickly and accurately determine the type of terrain under complex terrain conditions, such as rocks, gullies, slopes, etc.

[0089] When it is detected that the height of the obstacle exceeds 30% of the radius of the spherical tire 3, the intelligent control system will quickly trigger the leg-type motion mode. At this time, the system will control the joint servo motor 7 to move, so that the robot's thigh arm 5 and calf arm 6 work together to complete the action sequence of leg lifting-crossing-landing. The joint servo motor 7 has high-precision control capabilities and fast response characteristics, which can ensure that the robot moves smoothly and stably when crossing obstacles.

[0090] Omnidirectional mobile control module ( Figure 7): The core task of this module is to realize the omnidirectional movement of the robot spherical tire 3. The intelligent control system controls the driving servo motor 4 and adopts advanced vector control algorithm to accurately control the movement of the spherical tire 3. The vector control algorithm can accurately adjust the output torque and speed of the driving servo motor 4 according to the movement requirements of the robot, thereby realizing the flexible movement of the spherical tire 3 in three-dimensional space.

[0091] In order to achieve high-precision positioning, the intelligent control system uses the Kalman filter algorithm to fuse the data of the encoder and IMU (inertial measurement unit). The encoder can accurately measure the rotation angle and speed of the drive servo motor 4, and the IMU can provide the acceleration and angular velocity information of the robot. By fusing these data with the Kalman filter algorithm, the measurement error can be eliminated and the positioning accuracy of millimeters can be achieved.

[0092] When the turning radius of the spherical tire 3 is smaller than its diameter, the intelligent control system will start the zero-radius turning mode. In this mode, the system differentially controls the four drive servo motors 4 to enable the spherical tire 3 to rotate 360 ​​degrees in place. This zero-radius turning function enables the robot to flexibly change direction in a small space, greatly improving the robot's maneuverability.

[0093] Terrain compensation adjustment module ( Figure 8 ): When driving on terrains with different slopes, the robot needs to adjust the angle of the tire frame 2 to ensure driving stability. The intelligent control system achieves this function by controlling the angle servo motor 9. The output shaft of the angle servo motor 9 is connected to the pinion 10, and the pinion 10 is meshed with the large gear 8 fixed to the rotating shaft of the tire frame 2. When the angle servo motor 9 rotates, the tire frame 2 is driven to adjust the angle through the transmission of the pinion 10 and the large gear 8.

[0094] When the intelligent control system detects that the terrain slope is greater than 25°, it will start the graded compensation mechanism. First, the system will adjust the angle of the tire frame 2 to the maximum compensation position to increase the contact area between the robot and the ground and improve stability. If the robot still cannot meet the stability requirements after adjusting the tire angle, the system will trigger the leg support auxiliary function. At this time, the joint servo motor 7 will control the thigh arm 5 and the calf arm 6 to expand, providing additional support for the robot and ensuring the safe driving of the robot on steep terrain.

[0095] Intelligent protection module ( Fig. 9): The joint buffer of the robot plays an important protective role during the movement. The joint buffer adopts a spring damper structure, which can absorb the impact energy of the robot in real time during the movement. When the robot encounters bumps or collisions, the spring damper will deform and convert the impact energy into heat energy, thereby reducing the damage to the robot joints and internal components caused by the impact force.

[0096] A pressure sensor is installed in the cargo storage box 1 to monitor the status of the cargo in real time. When the cargo is bumped or squeezed during transportation, the pressure sensor will detect the change in pressure. If the pressure suddenly changes beyond the preset threshold, the intelligent control system will activate the secondary buffer device to further protect the safety of the cargo.

[0097] The driving servo motor 4 and the joint servo motor 7 are equipped with a protection system, and the automatic sensing sensors in the protection system include temperature sensors and humidity sensors. The temperature sensor can monitor the working temperature of the motor in real time. When the temperature exceeds 60°C, the intelligent control system will automatically start the heat dissipation program, such as turning on the cooling fan, to reduce the temperature of the motor. The humidity sensor is used to monitor the humidity of the working environment of the motor. When the humidity exceeds 80%RH, the system will start the moisture-proof program, such as turning on the heating element, to prevent the motor from being damaged by moisture. In addition, when the accelerometer detects that the acceleration of the robot is greater than 5g, the intelligent control system will trigger the emergency braking program and immediately stop the movement of the robot to avoid danger.

[0098] Environment Interaction Module( Fig.10 ): The robot's ambient light sensor can sense the light intensity of the surrounding environment in real time. When the ambient light is dim, the ambient light sensor will transmit a signal to the intelligent control system, which will trigger the LED light to turn on automatically to provide the necessary lighting for the robot's movement.

[0099] The ultrasonic sensor is mounted on the tire frame 2 to detect obstacles around the robot. When the ultrasonic sensor detects an obstacle, it sends a signal to the intelligent control system, which controls the LED light to adjust the irradiation angle so that the light can illuminate the obstacle and improve the robot's perception of the surrounding environment.

[0100] The intelligent control system is also equipped with a visual recognition algorithm that can identify pedestrians. When the visual recognition algorithm detects a pedestrian, the intelligent control system triggers a directional flashing warning mode. The LED light flashes at a specific frequency and pattern to alert pedestrians to the presence of the robot and avoid collision accidents.

[0101] To sum up, the multimodal motion control method of this embodiment enables the robot to adaptively adjust the motion mode, achieve omnidirectional movement, compensate for terrain changes, protect itself and cargo safety, and effectively interact with the surrounding environment in a complex environment through the collaborative work of various modules. It has high practicality and reliability.

[0102] How it works

[0103] (I) Principle of sports mode switching;

[0104] Intelligent perception and decision-making: The robot perceives the surrounding environment in real time through integrated lidar, camera, gyroscope and accelerometer sensors. The lidar obtains three-dimensional information of the terrain with a 360-degree scanning range and an accuracy of up to ±0.05 meters. The camera provides visual images to assist in judging terrain features and obstacle types. The gyroscope and accelerometer monitor the robot's own posture and motion state changes.

[0105] The intelligent control system conducts a comprehensive analysis of these sensor data based on a pre-set algorithm. When it is determined that the terrain is relatively flat, the control system issues a command to keep the robot in wheeled motion mode. At this time, the servo motor 4 drives the spherical tire 3 to rotate to achieve efficient and rapid movement. When an obstacle is detected ahead or the terrain is complex (such as a large slope, gullies, etc.), the control system quickly calculates and makes decisions, switching to legged motion mode within 0.5 seconds.

[0106] The wheel-leg mechanism works together: in the wheeled motion mode, the joint servo motor 7 controls the thigh arm 5 and the calf arm 6 to maintain a relatively fixed angle, so that the wheel-leg mechanism is similar to the structure of a traditional wheel, and the spherical tire 3 rolls forward driven by the driving servo motor 4. At this time, the angle adjustment component does not work and the tire frame 2 maintains a stable angle.

[0107] When switching to the leg movement mode, the joint servo motor 7 adjusts the angles of the thigh arm 5 and the calf arm 6 according to the control system instructions to realize the lifting and crossing of the legs. At the same time, the angle servo motor 9 accurately controls the overall angle of the tire frame 2 through the meshing transmission of the small gear 10 and the large gear 8, so that the spherical tire 3 can better adapt to terrain changes. For example, the tire angle is adjusted to increase grip when climbing a slope, and the tire position and angle are adjusted to achieve smooth crossing when crossing a gully.

[0108] (II) Power transmission and control principle

[0109] Driving servo motor drives spherical tire: Driving servo motor 4 receives speed and steering instructions from intelligent control system, adjusts the speed and steering of output shaft according to the instructions, and the power output by the motor is transmitted to spherical tire 3 through coupling, so that spherical tire 3 rotates around its own axis on tire frame 2, thereby pushing the robot forward, backward or turning. Due to the omnidirectional rotation characteristics of spherical tire 3, the robot can realize flexible operations such as turning on the spot, and has better maneuverability in narrow space.

[0110] Joint servo motor controls wheel-leg motion: joint servo motors 7 on cargo storage box 1 and calf arm 6 respectively control the motion of thigh arm 5 and calf arm 6. Joint servo motor 7 accurately controls the rotation angle and speed of motor output shaft according to the posture adjustment instruction of control system, and realizes leg flexion, extension, swing and other motions through mechanical connection with thigh arm 5 and calf arm 6. During the motion, rubber shock-absorbing pad reduces the influence of motor vibration on wheel-leg mechanism, and ensures the stability and accuracy of motion.

[0111] The angle servo motor adjusts the tire frame angle: the angle servo motor 9 controls the rotation of the pinion 10 according to the analysis results of the terrain and movement status of the intelligent control system. The meshing transmission of the pinion 10 and the large gear 8 converts the rotational motion of the angle servo motor 9 into the overall angle adjustment of the tire frame 2. The module, number of teeth and other parameters of the large gear 8 and the pinion 10 have been carefully designed to ensure the accuracy and stability of the angle adjustment, so that the tire frame 2 can be quickly and accurately adjusted to the required angle within the error range of ±0.5 degrees to meet the movement requirements under different terrain conditions.

[0112] (III) Buffering and protection principles

[0113] Leg joint buffering: During the movement of the robot, when the legs are impacted, the buffering device of the spring damper structure comes into play. The spring first undergoes elastic deformation to absorb part of the impact energy. Its elastic coefficient (between 50-100N / mm) is selected according to the weight of the robot and the expected impact load to ensure that the normal movement is not affected while effectively buffering the impact. The damper converts the energy of the spring rebound into heat energy through the flow resistance of the internal liquid. The damping coefficient (between 0.5-1.5Ns / mm) controls the smoothness of the buffering process, prevents the robot from excessively shaking due to impact, protects the joint servo motor 7 and the mechanical structure from damage, and at the same time improves the stability and comfort of the robot when walking on complex terrain and reduces the impact of vibration on the cargo.

[0114] Cargo protection: The cushion inside the cargo storage box 1 directly protects the cargo. When the robot bumps or collides during movement, the cushion absorbs energy through its own elastic deformation, reducing the impact force on the cargo. The fixing belt and hook made of high-strength nylon material firmly fix the cargo in the cargo storage box 1 to prevent the cargo from being displaced or falling due to the movement of the robot. During transportation, even if the robot encounters a large slope change or an obstacle impact, the cargo can remain stable, ensuring the safe transportation of the cargo.

[0115] (IV) Lighting and warning principles

[0116] Automatic lighting control: The automatic sensing sensor on the tire frame 2 monitors the ambient light intensity in real time. When the ambient light is lower than the set sensing sensitivity (between 0.1-0.5 lux), the sensor sends a trigger signal to the intelligent control system. After receiving the signal, the control system automatically controls the LED light to light up and provide lighting for the robot. The brightness of the LED light can be adjusted according to the ambient light intensity and the movement state of the robot. The maximum brightness is 100-200 lumens, and the lighting range can reach 5-10 meters in front, ensuring that the robot can clearly observe the surrounding terrain in a dimly lit environment, improving visibility and safety.

[0117] Function of warning sign: The warning sign on the tire frame 2 is made of reflective material, which can reflect strong light under light, and the visible distance is 50-100 meters. When there are other people or vehicles in the working environment of the robot, the warning sign can remind them to pay attention to the existence of the robot in time, avoid accidents such as collision, and ensure the safety of the robot in mountainous and hilly areas.

[0118] (V) Motor protection principle

[0119] Waterproof sealing and heat dissipation balance: The waterproof and sealed housing of the drive servo motor 4 and the joint servo motor 7 ensures that the motor works normally in a humid or watery mountain environment. The sealing level of the housing reaches above IP67, which can effectively prevent dust, mud and moisture from entering the motor. The waterproof plug and cable of the motor lead wire further enhance the waterproof performance. The protection level of the waterproof plug is IP68. At the same time, the heat dissipation structure inside the motor is optimized to ensure effective heat dissipation in a sealed environment. The heat sink transfers the heat generated by the motor to the housing, and then exchanges heat with the outside air through the ventilation holes. The dustproof net prevents dust from entering the ventilation holes and affecting the heat dissipation effect, ensuring that the motor operates within a stable temperature range and improving the reliability and service life of the motor.

[0120] The above description is only for illustrating the present invention. It should be understood that the present invention is not limited to the above embodiments, and various variations that conform to the concept of the present invention are within the protection scope of the present invention.

Claims

1. A wheel-leg combined multi-modal robot based on spherical tires, comprising a cargo storage box (1), characterized in that: The cargo storage box (1) is provided with four sets of wheel-leg mechanisms at the bottom, the four sets of wheel-leg mechanisms are rotatably connected to the tire frame (2) at the bottom, the four sets of wheel-leg mechanisms are provided with angle adjustment components for adjusting the overall angle of the tire frame (2), the tire frame (2) is rotatably connected to a spherical tire (3) and a fixedly connected driving servo motor (4), and the spherical tire (3) is driven by the driving servo motor (4).

2. A wheel-leg combined multi-modal robot based on spherical tires according to claim 1, characterized in that: The wheel-leg mechanism comprises a cargo storage box (1) having a thigh arm (5) hinged at the bottom, the thigh arm (5) having a calf arm (6) hinged, the cargo storage box (1) and the calf arm (6) both being provided with a joint servo motor (7), and the thigh arm (5) and the calf arm (6) being driven by the joint servo motor (7).

3. A wheel-leg combined multi-modal robot based on spherical tires according to claim 2, characterized in that: The calf arm (6) is rotationally connected to the tire frame (2), a large gear (8) is fixedly connected to the rotation shaft, an angle servo motor (9) is connected to the calf arm (6), and an output end of the angle servo motor (9) is connected to a small gear (10) meshing with the large gear (8).

4. The wheel-leg combined multi-modal robot based on spherical tires according to claim 3 is characterized in that: The thigh arm (5) and the calf arm (6) are both straight rod structures, and the connection parts between the joint servo motor (7) and the thigh arm (5) and the calf arm (6) are provided with rubber shock-absorbing pads.

5. The wheel-leg combined multi-modal robot based on spherical tires according to claim 4, characterized in that: It also includes an intelligent control system that integrates lidar, camera, gyroscope and accelerometer sensors.

6. The wheel-leg combined multi-modal robot based on spherical tires according to claim 5, characterized in that: The thigh arm (5) and the calf arm (6) are provided with a buffer device at their joints, and the buffer device adopts a spring damper structure.

7. The wheel-leg combined multi-modal robot based on spherical tires according to claim 6, characterized in that: A pressure sensor is provided in the cargo storage box (1), and an ultrasonic sensor, an ambient light sensor and an LED light are provided on the tire frame (2).

8. The wheel-leg combined multi-modal robot based on spherical tires according to claim 7, characterized in that: The driving servo motor (4) and the joint servo motor (7) are both provided with a waterproof and sealed housing, and the housing has a built-in temperature sensor and a humidity sensor.

9. A multimodal motion control method based on the robot according to claim 8, characterized in that: The following steps are involved: Terrain adaptive switching module: the laser radar collects terrain data in real time, combines the gyroscope attitude data, and the intelligent control system classifies the terrain through the fuzzy neural network algorithm of the accelerometer sensor; Omnidirectional movement control module: controls the driving servo motor (4), adopts a vector control algorithm to realize the three-dimensional movement of the spherical tire (3); and integrates the encoder and IMU data in the intelligent control system based on Kalman filtering to realize millimeter-level positioning; Terrain compensation adjustment module: controls the angle servo motor (9) to drive the tire frame (2) to adjust the angle through the engagement of the large gear (8) and the small gear (10); Intelligent protection module: The joint buffer device absorbs impact energy in real time; The pressure sensor in the cargo storage box (1) monitors the cargo status; The driving servo motor (4) and the joint servo motor (7) protection system, the automatic sensing sensor is a temperature sensor or a humidity sensor; Environmental interaction module: The ambient light sensor triggers the LED light to turn on automatically.

10. The multimodal motion control method of a robot according to claim 9, characterized in that: include: In the terrain adaptive switching module, when it is detected that the height of the obstacle exceeds 30% of the radius of the spherical tire (3), the leg-type motion mode is triggered to control the joint servo motor (7) to complete the leg-lifting-crossing-landing action sequence; In the omnidirectional movement control module, when the turning radius of the spherical tire (3) is less than the diameter of the spherical tire (3), the zero radius turning mode is started, and 360° rotation is achieved by differentially controlling the four driving servo motors (4); In the terrain compensation adjustment module, when the intelligent control system detects that the slope is greater than 25°, the graded compensation is started: first, the tire angle is adjusted to the maximum compensation position, and if the stability requirement is still not met, the leg support assistance is triggered, which is achieved by controlling the joint servo motor (7) in the above-mentioned vehicle; In the intelligent protection module, when the accelerometer detects an acceleration greater than 5g, emergency braking is triggered; When the pressure suddenly changes to more than the threshold, the secondary buffer is started; when the temperature sensor detects that the temperature is more than 60°C or the humidity sensor detects that the humidity is more than 80%RH, the heat dissipation or moisture-proof program is automatically started; In the environmental interaction module, when the ultrasonic sensor detects an obstacle, it controls the LED light to adjust the illumination angle, and when the intelligent control system detects a pedestrian through a visual recognition algorithm, it triggers a directional flashing warning mode.

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