Multi-mode four-footed robot dog with telescopic shanks

Abstract

The invention discloses a multi-mode four-footed robot dog with telescopic shanks, and belongs to the technical field of robots. The robot dog comprises a main body structure, a luffing mechanism, a thigh, a shank and a multi-mode sole, a main body structure is a cubic frame, a battery and a control system are integrated in the cubic frame, and front and rear ends are connected with a luffing mechanism through lug plates; the luffing mechanism is used for adjusting the distance between the soles, the thighs achieve rotary motion through the rotary module, the shanks are driven by the linear motors to achieve telescopic motion, the multi-mode foot soles integrate the hollow feet, the wheel assemblies, the supporting frames and the springs, and automatic switching between foot type motion and wheel type motion can be achieved through mechanical cooperation of stretching of the shanks, the thighs and the supporting frames. According to the robot dog, shank movement is changed into linear movement from rotation, a driving and transmission structure is simplified, lightweight design is achieved, meanwhile, wheel-foot rapid switching is achieved through shank movement, the multi-scene adaptive capacity of the robot dog is remarkably improved, and the robot dog can be widely applied to scenes such as complex terrain movement and multi-task operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and in particular relates to a multi-modal quadruped robot dog with retractable calves. Background Art

[0002] In today's era of rapid technological advancement, robotics, as a cutting-edge field integrating multiple disciplines, is profoundly changing people's production and lifestyles. As a key branch of robotics, robot dogs, with their unique advantages and broad application prospects, have attracted significant attention from both academia and industry.

[0003] From an application perspective, in the industrial sector, traditional inspection work often faces challenges such as harsh environments, high labor intensity, low efficiency, and high safety risks. For example, in industrial environments characterized by high temperatures, pressures, and radiation, manual inspections not only pose a threat to workers' health but also make it difficult to ensure accurate and timely inspections. Robot dogs, equipped with devices such as lidar, cameras, and gas sensors, can autonomously navigate complex industrial environments, accurately collect data, and monitor the environment. This significantly improves the accuracy and timeliness of inspections and ensures the safe operation of facilities. In the public safety and rescue sector, when faced with emergencies such as natural disasters and fires, the lives of rescue workers are often seriously threatened. Robot dogs can replace rescue workers in conducting reconnaissance and search operations in high-risk environments such as those characterized by toxicity, hypoxia, and collapse. They can proactively penetrate complex structures and intelligently detect objects and hazardous gases in all directions. They can also deliver rescue supplies and equipment to assist in the rescue effort, buying valuable time.

[0004] Although quadruped robot dogs have been applied in many fields, existing technologies still have certain limitations. Most of the soles of the feet adopt a single foot-type or wheel-type structure, which results in a relatively simple form of movement and an inability to switch quickly, resulting in a fixed application scenario. For example, the foot-type bionic structure has a strong obstacle-crossing ability, but the running speed is slow and the energy consumption is high; the wheeled structure has a fast running speed and low energy consumption, but the obstacle-crossing ability and stability are insufficient. At the same time, the calf of the bionic structure adopts a rotary structure, and the power of the drive motor is relatively large. When the drive motor is installed at the rotation of the forearm, the center of gravity of the motor is far away from the center of rotation of the thigh, resulting in a significant increase in the energy consumption of the thigh drive motor. When the forearm drive motor is installed at the thigh rotation, a transmission structure must be added, resulting in an increase in the overall weight.

[0005] Therefore, the present invention addresses the problems faced by the above-mentioned four-legged robot dog and develops a multi-modal four-legged robot dog with retractable calves, which is of great significance for improving the robot dog's mobility and reducing overall costs. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-modal quadruped robot dog with telescopic shanks that can quickly switch between wheel and foot positions, ensuring the robot's adaptability to multiple scenarios. This multi-modal quadruped robot dog with telescopic shanks changes the shank's motion from rotational to linear motion, simplifies the drive motor and transmission structure, and achieves a lightweight design. The wheel assembly is integrated into the foot structure, and the robot dog can quickly switch between foot and wheel positions by controlling the extension and contraction of the forearm, significantly improving its motion adaptability.

[0007] To achieve the above object, the present invention adopts the following design scheme: A multi-modal quadruped robot dog with retractable calves consists of a main body structure, a variable amplitude mechanism, thighs, calves and multi-modal soles. Figure 1 shown.

[0008] The main structure is a cubic frame with an integrated battery and control system to provide power and control operation; an ear plate is fixed to the front and rear ends respectively, and each ear plate has two through circular holes symmetrically opened along the axis. The amplitude adjustment module of the amplitude adjustment mechanism is inserted into the circular hole from the inside to the outside to form four driving joints; a number of threaded holes are evenly distributed on the circumference of the circular hole for fixing the amplitude adjustment mechanism to the ear plate through fasteners.

[0009] The amplitude changing mechanism includes an amplitude changing module and a connecting piece, such as Figure 2 As shown, it is used to adjust the distance between the soles of the feet to adapt to different terrains and ensure the smoothness of movement; the amplitude variation module includes a drive motor, a reducer, a transmission component, a rotary encoder, a position sensor and a modular housing. The drive motor outputs power through the reducer and the transmission component, and the rotary encoder and the position sensor provide real-time feedback of movement parameters; the connecting piece is an annular structure, and a frustum is integrally formed on its outer side. A connecting hole is provided in the center of the frustum, which is fixed to the output end of the amplitude variation module by a fastener; a plurality of assembly holes are evenly distributed on the annular surface of the connecting piece along the circumference for connection with the rotary module of the thigh.

[0010] The thigh includes a rotary module, a leg body and a guide rail. Figure 3 As shown, it is used to realize the rotational movement of the thigh and cooperate with the calf to complete multimodal movements; the rotation module includes a drive motor, a reducer, a transmission assembly, a rotary encoder, a position sensor and a modular housing. The drive motor drives the thigh to rotate around the joint through the transmission assembly, and the sensor feeds back the position information in real time; the leg body is a trapezoidal plate with an arc at one end, the arc end matches the output end of the rotation module and is fixed by bolts; 6 threaded holes are preset on the leg body for fixing the guide rail; the guide rail is a rectangular structure with a length less than the length of the leg body, and wedge-shaped grooves (for guiding) are provided on both sides thereof, and the bottom is fixed to the threaded holes of the leg body by bolts; a linear motor stator is bonded to the top surface of the guide rail, and the stator length is adapted to the maximum stroke of the calf.

[0011] The calf includes a linear motor, a connecting plate and a trapezoidal plate, which are used to realize telescopic movements and cooperate with the thigh and the amplitude change mechanism to complete movements such as forward, backward, translation, crawling, and standing; the stator of the linear motor is fixed to the top surface of the guide rail of the thigh, and the mover is fixed to the connecting plate; the connecting plate is a C-shaped structure, and its inner side cooperates with the wedge-shaped groove of the guide rail to form a sliding pair, which can slide back and forth along the guide rail; one end of the trapezoidal plate is fixed to the connecting plate by a bolt, and it extends and retracts synchronously with the linear motor mover; the other end is provided with a strip groove, which is used to limit the sliding stroke of the support frame of the multi-modal foot.

[0012] The multimodal foot comprises a hollow foot, a wheel assembly, a support frame and a spring, such as Figure 4 As shown, it is used to realize automatic switching between foot-type movement and wheel-type movement; the hollow foot is a cubic structure, with a receiving cavity (slightly larger than the wheel assembly) at the bottom, and an ear plate with a connecting hole at the top, which is fixed to the trapezoidal plate of the calf by bolts; the wheel assembly is integrated with the hub motor and the wheel, and can be driven to roll independently; the support frame is a Z-shaped structure, one end of which is rotatably connected to the wheel assembly, and the other end extends through the hollow foot to the strip groove of the calf and can slide along the groove; the spring is sleeved on the outside of the support frame, and one end of which is connected to the support frame. The spring is fixed to the support frame, and the other end is fixed to the trapezoidal plate of the calf. In the natural state, the spring is in a stretched state, and the wheel assembly is retracted into the accommodating cavity of the hollow foot through elastic force (foot-type state); when it is necessary to switch to the wheel-type state, the calf is controlled to contract, and the lower end of the thigh contacts and presses down on the support frame to overcome the spring force to push the wheel assembly out of the accommodating cavity, and the hub motor is started to achieve rolling; when it is necessary to switch back to the foot-type state, the calf is controlled to extend, and the thigh is disengaged from the support frame. The spring elastic force drives the wheel assembly to retract into the accommodating cavity to complete the mode switching.

[0013] Through the invention process, a multi-modal four-legged robot dog with telescopic legs and rapidly switchable wheels and feet was invented, which can achieve the purpose of improving traffic capacity and reducing overall costs.

[0014] Advantages and positive effects of the present invention: 1. The calf is driven by a linear motor to achieve telescopic movement. Compared with the traditional rotary motion calf structure, this eliminates the complex rotary transmission components, and the drive motor and transmission structure are simpler, effectively reducing the overall weight of the leg and improving the robot dog's movement flexibility and energy efficiency.

[0015] 2. The multimodal foot utilizes spring force to retract and extend the wheel assembly through mechanical coordination between the calf extension and retraction, the thigh, and the support frame. This eliminates the need for a dedicated mode switching drive mechanism. Switching is accomplished solely through the calf extension and retraction, resulting in a fast response and compact structure, reducing system complexity and failure rate.

[0016] 3. The foot-based locomotion mode can adapt to walking, crawling, standing, and other complex terrains (such as rough roads and steps), while the wheeled locomotion mode enables rapid rolling (such as on flat roads). The flexible switching between these two modes enables the robot dog to cope with diverse scenario requirements, significantly improving its environmental adaptability and task execution range.

[0017] 4. The variable amplitude mechanism can adjust the distance between the soles of the feet, cooperate with the coordinated control of the thigh rotation module and the calf extension and contraction, and combine with the rotary encoders and position sensors integrated in each module to achieve closed-loop control of motion parameters, ensuring the robot dog's posture stability and precise movements in different motion states.

[0018] 5. The simplified transmission structure reduces the number of parts and lowers manufacturing costs. The wheel-foot switching does not require additional power and is achieved only through mechanical coordination and spring force, which reduces energy consumption and improves the endurance of the entire machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a multi-modal quadruped robot dog with retractable lower legs according to the present invention.

[0020] Figure 2 This is a schematic diagram of the luffing mechanism of a multi-modal quadruped robot dog with telescopic lower legs according to the present invention.

[0021] Figure 3 This is a schematic diagram of the thigh of a multi-modal quadruped robot dog with retractable calves according to the present invention.

[0022] Figure 4 This is a schematic diagram of the multi-modal paws of a multi-modal quadruped robot dog with retractable calves according to the present invention.

[0023] 1-Main structure; 2-Luffing mechanism; 2.1-Luffing module; 2.2-Connecting parts; 3-Thigh; 3.1-Rotation module; 3.2-Leg body; 3.3-Guide rail; 4-Calf; 4.1-Linear motor; 4.2-Connecting plate; 4.3-Trapezoidal plate; 5-Multimodal foot; 5.1-Hollow foot; 5.2-Wheel assembly; 5.3-Support frame; 5.4-Spring DETAILED DESCRIPTION

[0024] 1. Overall structural assembly relationship The multimodal quadruped robot dog with retractable shanks described in this invention features a main structure that serves as the overall support base. Front and rear ear plates connect the four legs (each leg consisting of a thigh, shank, and multimodal foot, connected in sequence) via four luffing mechanisms. The luffing mechanism's connector is fixed to the thigh's rotary module. The thigh's guide rails mate with the stators of the shank's linear motors. The shank's trapezoidal plates connect to the hollow feet of the multimodal feet, forming a complete kinematic chain. A control system is integrated into the main structure and electrically connected to the luffing mechanism, thigh rotary module, shank linear motor, and multimodal foot's hub motors, enabling closed-loop control of motion parameters.

[0025] 2. Multimodal motion implementation (1) Foot movement mode When the robot dog is walking, crawling or standing, the control system controls the calf to be in an extended state: at this time, the spring is in a stretched state, and the wheel assembly is retracted into the accommodating cavity of the hollow foot through elastic force, and the bottom (surface) of the hollow foot contacts the ground to form a foot support.

[0026] Forward / backward: The distance between the left and right legs is adjusted through the amplitude adjustment mechanism. The thigh rotation module drives the thigh to swing around the joint, coordinating with the extension and contraction of the calf to achieve alternating leg steps. Translation: Control the synchronous swing of the same-side leg, adjust the opposite-side leg in the opposite direction, and compensate for the displacement by combining the calf extension and contraction; Standing: The thighs and calves of the four legs stretch in coordination, lifting the main structure to a preset height, and maintaining a stable posture through position sensors.

[0027] (2) Wheeled motion mode When the robot needs to move quickly, it switches to wheeled mode: the control system causes the lower legs to contract, the lower ends of the thighs to contact the support frame and continue pressing down, overcoming the spring force and pushing the wheel assembly out of the hollow foot until the wheels contact the ground and support the entire robot's weight. At this point, the hub motors activate, controlling the speed and direction of the four wheels (differential control achieves steering), enabling rapid rolling.

[0028] (3) Mode switching process Foot style → Wheel style: Contract the calf → Press the thigh down to support the frame → Push out the wheel assembly → Start the hub motor; Wheel type → foot type: the hub motor stops → the calf extends → the thigh separates from the support frame → the spring force pulls the wheel assembly back into the accommodation cavity → the hollow foot touches the ground.

[0029] 3. Key parameters and advantages The adjustment range of the amplitude adjustment mechanism is 0-200mm, which can adapt to channels or terrains of different widths; The maximum telescopic travel of the calf is 150mm, meeting the needs of wheel-foot switching and gait adjustment; The spring's elastic coefficient is 500N / m, ensuring the wheel assembly is stably stowed in the foot-stance state. During the shift, only 50-80N of pressure from the lower leg is required to push the wheel out. Compared with the existing technology, the present invention does not require an additional wheel-foot switching drive device, and realizes automatic mode switching through the mechanical coordination of the calf extension and contraction and the thigh and support frame, thereby simplifying the structure and reducing energy consumption.

[0030] This embodiment is only a preferred example of the present invention and does not limit the scope of protection of the present invention. Any equivalent modifications or replacements based on the technical principles of the present invention should be deemed to fall within the scope of protection of the present invention.

Claims

1. A multi-modal quadruped robot dog with retractable lower legs, characterized by: It includes the main structure, luffing mechanism, thigh, calf and multi-modal foot; The main structure is a cubic frame with an integrated battery and control system. A lug plate is fixed to the front and rear ends respectively. Two through-holes are symmetrically provided on each lug plate along the axis. The luffing module of the luffing mechanism is inserted into the circular holes from the inside to the outside to form four driving joints. Several threaded holes are evenly distributed around the circular holes for fixing the luffing mechanism to the lug plates with fasteners. The amplitude variation mechanism includes an amplitude variation module and a connecting piece. The amplitude variation module includes a drive motor, a reducer, a transmission assembly, a rotary encoder, a position sensor, and a modular housing. The drive motor outputs power through the reducer and transmission assembly, and the rotary encoder and the position sensor provide real-time feedback of motion parameters. The connecting piece is an annular structure with a frustum integrally formed on its outer side. A connecting hole is provided in the center of the frustum and is fixed to the output end of the amplitude variation module by a fastener. The annular surface of the connecting piece has multiple assembly holes evenly distributed along the circumference for connection to the thigh rotary module. The thigh includes a rotary module, a leg body and a guide rail. The rotary module includes a drive motor, a reducer, a transmission assembly, a rotary encoder, a position sensor and a modular housing. The drive motor drives the thigh to rotate around the joint through the transmission assembly, and the sensor feeds back position information in real time. The leg body is a trapezoidal plate with an arc at one end. The arc end matches the output end of the rotary module and is fixed by bolts. Six threaded holes are preset on the leg body for fixing the guide rail. The guide rail is a rectangular structure with a length less than the length of the leg body. Wedge-shaped grooves are opened on its two side surfaces. The bottom is fixed to the threaded holes of the leg body by bolts. The top surface of the guide rail is bonded with a linear motor stator, and the stator length is adapted to the maximum stroke of the calf. The calf includes a linear motor, a connecting plate, and a trapezoidal plate. The stator of the linear motor is fixed to the top surface of the guide rail of the thigh, and the mover is fixedly connected to the connecting plate. The connecting plate has a C-shaped structure, and its inner side cooperates with the wedge-shaped groove of the guide rail to form a sliding pair, which can slide back and forth along the guide rail. One end of the trapezoidal plate is fixed to the connecting plate by a bolt, and it expands and contracts synchronously with the linear motor mover. The other end is provided with a strip groove for limiting the sliding travel of the support frame of the multimodal foot. The multimodal foot includes a hollow foot, a wheel assembly, a support frame and a spring. The hollow foot is a cubic structure, and a accommodating cavity is provided at the bottom thereof, which is slightly larger than the wheel assembly. An ear plate with a connecting hole is provided on the top, which is fixed to the trapezoidal plate of the calf by bolts; the wheel assembly is integrated with a hub motor and a wheel; the support frame is a Z-shaped structure, one end of which is rotatably connected to the wheel assembly, and the other end extends through the hollow foot to the strip groove of the calf and can slide along the groove; the spring is sleeved on the outside of the support frame, one end of which is fixed to the support frame, and the other end is fixed to the trapezoidal plate of the calf. In the natural state, the spring is in a stretched state, and the wheel assembly is retracted into the accommodating cavity of the hollow foot by elastic force; when the calf contracts, the lower end of the thigh contacts the support frame and presses down, overcoming the spring force to push the wheel assembly out of the accommodating cavity. When the calf is extended, the thigh is out of contact with the support frame, and the spring force drives the wheel assembly to retract into the accommodating cavity.

2. The multi-modal quadruped robot dog with retractable lower legs according to claim 1, characterized in that: The control system is electrically connected to the amplitude variation mechanism, the thigh rotation module, the calf linear motor and the hub motor of the multi-modal foot respectively to achieve closed-loop control of motion parameters.

3. The multi-modal quadruped robot dog with retractable lower legs according to claim 1, characterized in that: The adjustment range of the amplitude variation mechanism is 0-200 mm.

4. The multi-modal quadruped robot dog with retractable lower legs according to claim 1, characterized in that: The maximum telescopic stroke of the calf is 150 mm.

5. The multi-modal quadruped robot dog with retractable lower legs according to claim 1, characterized in that: The elastic coefficient of the spring is 500 N / m.

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