Mechanical arm working mechanism, cleaning assembly and sanitation vehicle thereof

Abstract

The application discloses a mechanical arm operation mechanism, a cleaning assembly and a sanitation vehicle, and relates to the technical field of mechanical arms, and can be used for expanding the operation range of the sanitation vehicle, cleaning garbage in areas that cannot be reached by the sanitation vehicle body, effectively improving the overall cleaning rate, and reducing the risk of equipment damage and personnel injury.

Description

Technical Field

[0001] This invention relates to the field of sanitation equipment technology, and in particular to a robotic arm operating mechanism, a sweeping assembly and a sanitation vehicle thereof. Background Technology

[0002] Most existing robotic cleaning arms have only two degrees of freedom, resulting in severely insufficient ability to adjust the sweeping disc's posture. When facing complex geometric shapes such as curbs, slopes, and corners, it is difficult to ensure the sweeping disc makes contact at the correct angle, leading to numerous cleaning dead zones. For example, patent CN112030769A discloses a height-adjustable and foldable cleaning head. Its joint drive is an electric push rod, which lacks reverse drive capability. In the event of an unexpected collision, the robotic arm acts like a rigid rod, unable to absorb the impact, making the sweeping brush and arm body extremely prone to breakage, potentially even causing injury to pedestrians.

[0003] While industrial collaborative robotic arms can provide some flexibility and collision compliance, the overall cost is usually several times that of a simple swing arm. In vehicle-mounted and outdoor environments, dust, rain, and continuous vibration can easily cause the collaborative arm's sensors to drift and fail, resulting in a high maintenance rate. Furthermore, the end-of-line cleaning mechanism still needs to be redeveloped and adapted, making it impossible to directly form a cost-effective overall operating system. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a robotic arm operating mechanism, a sweeping assembly, and a sanitation vehicle thereof, which has a large range of sweeping posture adjustment and is stable and reliable.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This application provides a robotic arm operating mechanism, including a robotic arm and a sweeping mechanism. The robotic arm is a five-degree-of-freedom robotic arm. The five-degree-of-freedom robotic arm includes a base, a waist section, an upper arm, a lower arm, a wrist, an end-mounted flange, and joint modules J1, J2, J3, J4, and J5. The sweeping mechanism is connected to the end-mounted flange. The J1 joint module is used to drive the waist section to rotate relative to the base. The J2 joint module is used to drive the upper arm to swing up and down relative to the waist section. The J3 joint module is used to drive the lower arm to swing up and down relative to the upper arm. The J4 joint module is used to drive the wrist to pitch up and down relative to the lower arm. The J5 joint module is used to drive the end-mounted flange to roll.

[0006] Further or preferred: It also includes a gravity compensation mechanism, the upper end of which is hinged to the upper arm and the lower end of which is hinged to the waist.

[0007] The gravity compensation mechanism is a spring rod structure, with one end of the spring rod structure hinged above the waist and the other end of the spring rod structure hinged to the end of the upper arm.

[0008] Both ends of the spring rod structure are equipped with hinge structures, which are connected to the waist and upper arm respectively through the two hinge structures.

[0009] When the boom is in a vertical position, the eccentricity of the boom's center of gravity is small, and the compensating torque output by the spring-pull rod structure is small. When the boom rotates to a horizontal position, the eccentricity of the boom's gravity increases, and the hinge at the end of the boom pulls the spring-pull rod structure to stretch, outputting a larger compensating torque.

[0010] The joint structures on both the upper arm and forearm adopt a double-support structure.

[0011] The dual-support structure is a pair of bearing structures located on both sides of the joint structure.

[0012] It also includes a six-dimensional torque sensor for sensing ground undulations, which is connected between the end mounting flange and the sweeping disc mechanism.

[0013] The sweeping mechanism includes a sweeping support, a drive structure, a sweeping mounting flange, and a sweeping disc. The drive structure is mounted on the sweeping support and connected to the sweeping mounting flange, and the sweeping disc is mounted on the sweeping mounting flange.

[0014] The sweeping plate bracket is equipped with a connecting plate, a six-dimensional torque sensor is installed on one side of the connecting plate, and the drive structure is located on the other side of the connecting plate.

[0015] It also includes a robotic arm controller for adjusting the height of the robotic arm end-effector relative to the ground and the contact pressure in real time, the robotic arm controller being connected to a six-dimensional torque sensor.

[0016] The J4 joint module is rear-mounted and fixed. The J4 joint module drives the wrist to complete the pitch motion setting relative to the forearm through a double linkage mechanism.

[0017] All of the joint modules described herein are planetary integrated joint modules.

[0018] The planetary integrated joint module is a planetary integrated structure with anti-drag capability.

[0019] The five-degree-of-freedom robotic arm achieves spatial position adjustment of the sweeping mechanism through joint modules J1, J2, and J3, and sweeping posture adjustment through modules J4 and J5.

[0020] This application provides a cleaning assembly, including the robotic arm working mechanism, and the base is provided with a mounting and fixing structure.

[0021] This application provides a sanitation vehicle, including a vehicle body and the sweeping assembly, wherein the sweeping assembly is mounted on the vehicle body via a mounting and fixing structure.

[0022] The front of the vehicle body is provided with a swing arm structure, and the base of the robotic arm working mechanism is fixed on the swing arm structure.

[0023] The front of the vehicle body is provided with a stepped structure, and one end of the swing arm structure is located on the stepped structure.

[0024] Compared with the prior art, the present invention has the following advantages: The robotic arm operating mechanism, sweeping assembly, and sanitation vehicle are rationally designed. This sanitation vehicle is equipped with a five-degree-of-freedom robotic arm operating mechanism, which on the one hand can expand the operating range of the sanitation vehicle and sweep up garbage in areas that the vehicle body cannot reach, effectively improving the overall cleaning rate; on the other hand, the robotic arm has excellent impact resistance, can adapt to complex working conditions, and reduce the risk of equipment damage and personnel injury; and it is equipped with a gravity compensation mechanism to reduce the load torque of the joint module, reduce the joint volume, and reduce the energy consumption of the robotic arm operation. Attached Figure Description

[0025] The following is a brief explanation of the contents of each of the accompanying drawings and the markings in the drawings: Figure 1 This is a schematic diagram of the robotic arm operating mechanism of the present invention.

[0026] Figure 2 This is a schematic diagram of the working mechanism of the present invention installed on a sanitation vehicle.

[0027] Figure 3 This is a schematic diagram of the robotic arm structure of the present invention.

[0028] Figure 4 This is a schematic diagram of the robotic arm joint module of the present invention.

[0029] Figure 5 This is a schematic diagram of the gravity compensation mechanism of the present invention.

[0030] Figure 6 This is a schematic diagram of the sweeping mechanism of the present invention.

[0031] Figure 7 This is a schematic diagram of the J3 joint of the present invention.

[0032] Figure 8 This is a schematic diagram of the cross-section of the J3 joint of the present invention.

[0033] Figure 9 This is a schematic diagram of the J1 and J2 joints of the present invention.

[0034] Figure 10 This is a schematic diagram of the cross-section of joint J1 in this invention.

[0035] Figure 11 This is a schematic diagram of the cross-section of the J2 joint of the present invention.

[0036] Figure 12 This is a schematic diagram of the J4 joint of the present invention.

[0037] Figure 13 This is a schematic diagram of the cross-section of the J4 joint of the present invention.

[0038] In the picture: 1-Robotic arm, 2-Gravity compensation mechanism, 3-Sweeping mechanism; 11-Base, 12-Waist, 13-Upper arm, 14-Forearm, 15-Wrist, 16-End mounting flange, 17-J1 joint module, 18-J2 joint module, 19-J3 joint module, 1901-Cross roller bearing, 1902-Deep groove ball bearing, 110-J4 joint module, 111-J5 joint module; 21-Hinge I, 22-Hinge II, 23-Spring pull rod mechanism; 31-Six-dimensional torque sensor, 32-Sweeping disc bracket, 33-Motor, 34-Reducer, 35-Sweeping disc mounting flange, 36-Sweeping disc. Detailed Implementation

[0039] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and through the description of the examples.

[0040] Although the invention has been shown and described herein with reference to specific embodiments, it is not intended to be limited to the details shown. Rather, various modifications in detail may be made within the equivalent scope and scope of the claims without departing from the invention. In the drawings, the same item numbers refer to the same elements.

[0041] Throughout this disclosure, various terms are used to describe the physical shape or arrangement of features. Many of these terms are used to describe features conforming to a cylindrical or generally cylindrical geometry with the feature as its radius and a central axis perpendicular to that radius. Unless otherwise specified, the terms are given the following meanings: The terms “longitudinal,” “longitudinal,” “axial,” and “axial” refer to a direction, dimension, or orientation parallel to the central axis. The terms “radial” and “radially” refer to a direction, dimension, or orientation perpendicular to the central axis. The terms “inward” and “inner” refer to a direction, dimension, or orientation extending radially toward the central axis. The terms “outward” and “outer” refer to a direction, dimension, or orientation extending radially away from the central axis.

[0042] In this specification, relative terms such as “horizontal,” “vertical,” “upward,” “downward,” “top,” and “bottom,” and their derivatives (e.g., “horizontal,” “downward,” “upward,” etc.) should be interpreted as referring to the direction described or the direction shown in the accompanying drawings. These relative terms are for ease of description and are not generally intended to require a specific direction.

[0043] When unmanned sanitation vehicles clean areas such as curbs, guardrail bases, and step corners, a robotic arm is needed to drive the sweeping disc to approach the work surface in a suitable position. Currently, most sanitation vehicle sweeping arms are simple swing arms with two to three degrees of freedom. The joints are driven by hydraulic cylinders or worm gears with a high reduction ratio, and the end is rigidly connected to the sweeping disc. This method is simple in structure and low in cost, but it lacks flexibility. Furthermore, due to the reverse self-locking of the joints, if the sweeping disc or arm accidentally touches a curb, obstacle, or pedestrian, it cannot passively retreat, which can easily cause mechanical damage or injury.

[0044] Existing robotic sweepers have only two degrees of freedom, resulting in severely insufficient ability to adjust the sweeping disc's posture. When facing complex geometric shapes such as curbs, slopes, and corners, they struggle to ensure the sweeping disc makes contact at the correct angle, leading to numerous cleaning dead zones. Furthermore, their joints are driven by electric push rods, lacking reverse drive capability. In the event of an unexpected collision, the robotic arm acts like a rigid rod, unable to absorb impact, making the sweeping brush and arm highly susceptible to breakage, resulting in poor safety and reliability.

[0045] To achieve greater flexibility and safer interaction, some solutions have attempted to introduce industrial collaborative robotic arms. However, existing collaborative robotic arms are not designed for sanitation vehicle operation conditions. They have insufficient protection levels and vibration resistance, poor reverse drive capability of harmonic reducers, and will lock up the brakes after a collision alarm. On sanitation vehicles with a certain braking distance, this can easily cause injury to the robotic arm and personnel. They are more suitable for static installation operations, and the overall cost is high. After installation on a vehicle, the system cost increases significantly, making it difficult to promote on a large scale in the sanitation industry. At the same time, an additional sweeping device still needs to be installed at the end, resulting in low integration.

[0046] Therefore, there is an urgent need for a specialized robotic arm operating mechanism that is designed for sanitation cleaning operations, takes into account high degree of freedom of operation, high passive safety and anti-drive capability, and is cost-controllable.

[0047] The technical problem to be solved by this application is to provide a multi-degree-of-freedom robotic arm operating mechanism for sanitation vehicles, so as to overcome the problems of insufficient degrees of freedom and lack of collision anti-drive capability, easy damage and injury of existing simple sweeping arms, and the high cost and poor environmental adaptability of transplanting cooperative arms, so as to achieve flexible operation with multiple degrees of freedom, high passive safety and low cost and durability in sanitation sweeping.

[0048] like Figures 1 to 13 As shown, this application provides a multi-degree-of-freedom robotic arm operating mechanism for sanitation vehicles, including a five-degree-of-freedom robotic arm 1, a gravity compensation mechanism 2, and a sweeping mechanism 3.

[0049] The five-degree-of-freedom robotic arm 1 includes a base 11, a waist 12, an upper arm 13, a lower arm 14, a wrist 15, an end-mounted flange 16, and joint modules J1 17, J2 18, J3 19, J4 110, and J5 111; the sweeping mechanism 3 is connected to the end-mounted flange 16. J1 joint module 17 is used to drive the waist to rotate relative to the base; J2 joint module 18 is used to drive the upper arm to swing up and down relative to the waist; J3 joint module 19 is used to drive the forearm to swing up and down relative to the upper arm; the coordinated motion of J1 joint module, J2 joint module, and J3 joint module controls the spatial position adjustment of the end effector in the X, Y, and Z directions. J4 joint module 110 is used to drive the wrist to perform pitching motion relative to the forearm; J5 joint module 111 is used to drive the end mounting flange to perform rolling motion, and the sweeping mechanism is mounted on the end mounting flange; through the coordinated movement of J4 joint module and J5 joint module, the sweeping mechanism mounted on the end mounting flange is ensured to maintain a preset pitch angle and roll angle with the ground.

[0050] In some embodiments, the upper end of the gravity compensation mechanism 2 is hinged to the upper arm 13, and the lower end of the gravity compensation mechanism 2 is hinged to the waist 12.

[0051] Preferably, the gravity compensation mechanism 2 is a spring rod structure, with one end of the spring rod structure hinged to the upper part of the waist and the other end of the spring rod structure hinged to the end of the upper arm; other elastic structures can also be used for the gravity compensation mechanism. The spring rod structure has hinges at both ends, which connect to the waist and upper arm respectively. The structure is stable and reliable, and easy to install.

[0052] When the boom is in a vertical position, the eccentricity of the boom's center of gravity is small, and the compensating torque output by the spring-pull rod structure is small. When the boom rotates to a horizontal position, the gravitational eccentricity of the boom increases, and the hinge at the end of the boom pulls the spring-pull rod structure to stretch, outputting a larger compensating torque. This reduces the load torque borne by the J2 joint module and reduces the energy consumption of the robotic arm operation.

[0053] The gravity compensation mechanism has a compact overall layout. During the operation of the robotic arm rotating around the waist, the gravity compensation mechanism will not encroach on the external space around the robotic arm.

[0054] In some embodiments, the spring rod structure may employ a tension spring adjusting rod assembly and a gas spring assembly; preferably, a tension spring adjusting rod assembly.

[0055] The tension spring adjusting rod assembly includes an adjusting rod, a tension spring, a spring stop, a hinge joint, and an adjusting nut; one end hinge joint - adjusting rod (with external thread) - spring stop - tension spring - other end hinge joint; the adjusting nut is fitted on the adjusting rod to change the spring pre-compression and pre-tension.

[0056] When the boom swings to the horizontal, the distance between the two hinge points increases, the tension spring is stretched, the spring force increases, and the output compensation torque increases; when the boom returns to the vertical position, the spring retracts, and the tension decreases. The spring preload can be adjusted via a threaded nut to adapt to different booms and sweeper loads; it does not occupy the rotational radial space and will not cause rotational interference.

[0057] In some embodiments, the J4 joint module 110 is rear-mounted and fixed, and the J4 joint module drives the wrist to complete the pitch motion setting relative to the forearm through a double linkage mechanism.

[0058] All joint modules adopt planetary integrated joint modules; the planetary integrated joint modules are planetary integrated structures with anti-drag capabilities.

[0059] The five-degree-of-freedom robotic arm achieves spatial position adjustment of the sweeping mechanism through joint modules J1, J2, and J3, and sweeping posture adjustment through modules J4 and J5.

[0060] In this invention, joint modules 17 (J1), 18 (J2), 19 (J3), 110 (J4), and 111 (J5) all adopt planetary integrated joint modules, which reduces the overall material cost while meeting operational performance requirements. The planetary integrated joint modules have reverse drive capability. When the sweeping mechanism is subjected to impact loads from the ground or obstacles, the joints can passively rotate in the opposite direction to buffer external impact loads and protect the robotic arm body and the sweeping mechanism.

[0061] In some embodiments, the present invention further includes a six-dimensional torque sensor 31 for sensing ground undulation, the six-dimensional torque sensor 31 being connected between the end mounting flange 16 and the sweeping mechanism 3.

[0062] The sweeping mechanism 3 includes a sweeping disc bracket 32, a drive structure, a sweeping disc mounting flange 35, and a sweeping disc 36. The drive structure is mounted on the sweeping disc bracket and connected to the sweeping disc mounting flange, and the sweeping disc is mounted on the sweeping disc mounting flange. The drive structure includes an integrated motor 33 and a reducer 34 for easy layout and installation.

[0063] The sweeping plate bracket 32 ​​is equipped with a connecting plate, the six-dimensional torque sensor 31 is installed on one side of the connecting plate, and the drive structure is located on the other side of the connecting plate, making the structure compact.

[0064] The six-dimensional torque sensor 31 is positioned between the end-mounted flange of the robotic arm and the sweeping mechanism. The sweeping mechanism integrates the motor and reducer into a single drive structure, simplifying the number of parts and facilitating the overall layout and assembly. The sweeping bracket is equipped with a connecting plate, on which the six-dimensional torque sensor is positioned on one side and the integrated drive structure on the other side. The sensor and drive components are positioned on opposite sides of the connecting plate, ensuring that the arrangement of each component does not interfere with each other. The overall structure is compact, effectively controlling the volume and weight of the sweeping mechanism's end, and preventing excessive end load from increasing the load pressure on the joints of the robotic arm.

[0065] The six-dimensional torque sensor 31 can sense the multi-dimensional force and torque information generated by the ground undulation and the contact between the sweeping disc and the ground in real time, providing raw data for the impedance control of the robotic arm. Combined with the integrated drive structure to drive the sweeping disc to rotate, it can not only ensure the stable rotation of the sweeping disc for cleaning, but also adjust the height of the sweeping disc relative to the ground and the contact pressure in real time based on the sensor feedback signal. This allows the sweeping disc to adapt to complex road surfaces with varying textures and ensures stable ground pressure. While improving the cleaning effect, it can also prevent the sweeping disc from being damaged by hard impacts from the ground, thus extending the service life of the sweeping disc and end components.

[0066] Furthermore, the present invention also includes a robotic arm controller for real-time adjustment of the height and contact pressure of the robotic arm's end-effector relative to the ground. The robotic arm controller is connected to a six-dimensional torque sensor. Based on the signal collected by the six-dimensional torque sensor, the robotic arm controller uses an impedance control algorithm to adjust the height and contact pressure of the robotic arm's end-effector relative to the ground in real time, adapting to complex road cleaning conditions.

[0067] The robotic arm controller is electrically connected to the six-dimensional torque sensor 31, receiving multi-dimensional force and torque signals collected by the sensor, and using an impedance control algorithm to achieve closed-loop adjustment. It can adjust the height of the sweeping disc relative to the ground and the contact pressure in real time according to the actual undulation of the ground. There is no need to accurately model the road surface in advance. It can adapt to complex sweeping surfaces such as uneven surfaces, steps, and gravel, thus broadening the applicable scenarios of the mechanism.

[0068] This control method can maintain a stable and reasonable grounding pressure on the sweeping disc: when the grounding pressure is too high, the sweeping disc is automatically raised to avoid excessive wear of the sweeping disc and additional impact load on the joints; when the grounding pressure is insufficient, the sweeping disc is automatically lowered to ensure the cleaning effect of ground garbage; at the same time, it can buffer the impact of road obstacles, reduce the impact damage to the sweeping disc and the end joint of the robotic arm, extend the service life of the whole machine parts, and improve the stability of unmanned sanitation operation.

[0069] In some embodiments, the joint structures on the upper arm 13 and the lower arm 14 both adopt a double support structure; the double support structure is a pair of bearing structures arranged on both sides of the joint structure.

[0070] Taking the J2 joint module as an example, the output end of the J2 joint module 18 is connected to one side of the upper arm through a cross roller bearing and transmits torque to the upper arm. The other end of the J2 joint module is connected to the other side of the upper arm through a deep groove ball bearing to achieve auxiliary support. The overall rigidity of the robotic arm is improved through the dual support connection structure.

[0071] This application provides a cleaning assembly, including the robotic arm working mechanism, with a mounting and fixing structure on its base. The mounting and fixing structure can be a flange structure, which facilitates installation and fixing.

[0072] The robotic arm operating mechanism and cleaning assembly of this application are reasonably designed. This sanitation vehicle is equipped with a five-degree-of-freedom robotic arm operating mechanism, which on the one hand can expand the operating range of the sanitation vehicle and clean up garbage in areas that the vehicle body cannot reach, effectively improving the overall cleaning rate; on the other hand, the robotic arm has excellent impact resistance, can adapt to complex working conditions, and reduce the risk of equipment damage and personnel injury; and it is equipped with a gravity compensation mechanism to reduce the load torque of the joint module, reduce the joint volume, and reduce the energy consumption of the robotic arm operation.

[0073] This application provides a sanitation vehicle, including a vehicle body and a sweeping assembly, wherein the sweeping assembly is mounted on the vehicle body via a mounting and fixing structure.

[0074] Furthermore, the front of the vehicle body is equipped with a swing arm structure, and the base of the robotic arm working mechanism is fixed on the swing arm structure.

[0075] The front of the vehicle body is provided with a stepped structure, and one end of the swing arm structure is located on the stepped structure.

[0076] The sweeping assembly is integrally assembled onto the vehicle body using a mounting and fixing structure, enabling modular installation and facilitating the overall disassembly, inspection, and replacement of the sweeping assembly. The base of the robotic arm operating mechanism is fixed to the swing arm structure at the front of the vehicle body, with one end of the swing arm structure installed at the step structure at the front of the vehicle body. The step structure provides a stable mounting reference surface for the swing arm structure, making full use of the step installation space at the front of the vehicle body, rationally allocating the overall vehicle layout, avoiding spatial interference between the robotic arm operating mechanism and the original components of the vehicle body, and facilitating assembly and positioning.

[0077] The robotic arm operating mechanism is positioned on the swing arm structure at the front of the vehicle body. The swing arm structure can further expand the operating range of the robotic arm operating mechanism, making it easier for the robotic arm to deliver the sweeping disc mechanism to areas that are difficult for conventional cleaning components to reach, such as the perimeter of the vehicle body and the sides of the front of the vehicle, to carry out cleaning operations. The stepped structure supports the swing arm structure, which can improve the installation and support rigidity of the swing arm, reduce the swaying and deformation of the swing arm during operation, ensure the positional accuracy of the robotic arm operating mechanism during operation, and improve the cleaning reliability in complex scenarios.

[0078] Compared with existing technologies, this invention has the following advantages: 1. The operating range of the unmanned sanitation vehicle is increased. The adoption of a 5-DOF robotic arm allows it to adapt to more complex terrain, sweeping garbage from areas inaccessible to sanitation vehicles to designated areas, thereby improving the cleaning efficiency of the sanitation vehicle's operations; 2. The robotic arm has better impact resistance, can cope with more complex operating conditions, and is less likely to cause injury to the robotic arm or personnel; 3. The joints use planetary modules, which significantly reduce costs while meeting operational requirements, thus improving the product's market competitiveness; 4. The use of a gravity compensation mechanism reduces the load torque requirement on the J2 joint module of the robotic arm, reduces the joint module size, and lowers the energy consumption of the robotic arm.

[0079] This application provides a multi-degree-of-freedom robotic arm operating mechanism for sanitation vehicles, the specific structure and principle of which are described below: Detailed structural scheme description: The five-degree-of-freedom robotic arm includes: a base 11, a waist section 12, an upper arm 13, a forearm 14, a wrist section 15, an end-mounted flange 16, and joint modules J1, J2, J3, J4, and J5. Joint module J1 controls the rotation of the waist section relative to the base; joint module J2 controls the up-and-down swing motion of the upper arm relative to the waist section; joint module J3 controls the up-and-down swing motion of the forearm relative to the upper arm. Through J1, J2, and J3, the spatial position of the robotic arm's end-mounted arm in the X, Y, and Z directions can be controlled. Joint module J4 controls the pitch motion of the wrist relative to the forearm; joint module J5 controls the roll motion of the end-mounted flange. By controlling J4 and J5, the actuator (sweeping disc mechanism) mounted on the end-mounted flange maintains a preset pitch and roll angle with the ground. The J1, J2, J3, J4 and J5 joint modules are all planetary integrated joint modules. They adopt a small transmission ratio, which, while meeting the end-effector accuracy requirements, also gives the joints a certain degree of counter-drive capability and impact resistance, enabling the robotic arm as a whole to have a greater ability to resist external impacts.

[0080] The robotic arm joints adopt a dual-support structure; for example, the J2 joint module, the output end of the J2 joint module is connected to one side of the main arm through a cross roller bearing, thereby transmitting torque to the main arm; the other end is connected to the other side of the main arm through a deep groove ball bearing to play an auxiliary support role, thereby ensuring that the joint module and the main arm are connected through a dual-support mechanism, thereby improving the overall rigidity of the robotic arm.

[0081] Gravity compensation mechanism 2 is used to compensate for part of the load and weight of the robotic arm's end effector, thereby reducing the load on the J2 joint module of the robotic arm. This gravity compensation mechanism is a spring-pull rod mechanism, with one end hinged to the upper part of the arm and the other end hinged to the end of the upper arm. When the upper arm is in a vertical position, the center of gravity of the upper arm is relatively eccentric, and the compensation torque provided by the spring is relatively small. As the upper arm gradually moves to a horizontal position, its gravitational eccentricity increases, and the hinge at the end of the upper arm will further stretch the spring, thereby providing a larger compensation torque, reducing the load torque requirement on the J2 joint module, and thus reducing the operating energy consumption of the robotic arm. In addition, this structure is compact, and the robotic arm will not encroach on the space around the waist when rotating around the arm.

[0082] The sweeping mechanism 3 includes a six-dimensional torque sensor 31, a sweeping disc bracket 32, a motor 33, a reducer 34, a sweeping disc mounting flange 35, and a sweeping disc 36. The entire sweeping mechanism is mounted on the end-mounted flange of the robotic arm. Joints J1, J2, and J3 control the spatial position of the sweeping disc in the X, Y, and Z directions, while joints J4 and J5 control the pitch and roll angles of the sweeping disc relative to the ground. This ensures that the robotic arm can determine the sweeping position, rotation direction, speed, and angle of the sweeping disc based on the cleaning strategy. The six-dimensional torque sensor connects the sweeping mechanism to the end-mounted flange of the robotic arm and senses the undulations of the ground. The robotic arm controller can adjust the height and contact pressure of the sweeping disc relative to the ground through impedance control of this torque sensor, enabling the sweeping mechanism to adapt to cleaning complex road surfaces.

[0083] Wrist structure design: The J4 joint module, which controls the rotation of the wrist structure, is rear-mounted and fixed. The pitch movement of the wrist relative to the forearm is controlled by a double linkage mechanism, making the wrist structure more compact. At the same time, it also allows the center of gravity of the robotic arm to be placed at the rear, reducing the load torque requirements of the J2 and J3 joint modules.

[0084] Working principle explanation: The robotic arm's configuration ensures the spatial accessibility and attitude angle control of the end effector. Joints J1, J2, and J3 control the spatial position of the sweeping disc in the X, Y, and Z directions, while joints J4 and J5 control the pitch and roll angles of the sweeping disc relative to the ground. This allows the robotic arm to determine the sweeping position, rotation direction, speed, and angle of the sweeping disc based on the cleaning strategy. The end effector is equipped with a force control device that senses the unevenness of the ground. The robotic arm controller can adjust the height and contact pressure of the sweeping disc relative to the ground through impedance control of this torque sensor, enabling the sweeping disc mechanism to adapt to cleaning complex road surfaces.

[0085] The gravity compensation mechanism can appropriately compensate for the load torque of the J2 joint of the robotic arm according to the eccentricity of the upper arm. On the one hand, it can reduce the size of the J2 joint module of the robotic arm, making the structure more compact, and on the other hand, it can reduce the energy consumption of the robotic arm operation.

[0086] All robotic arm joint modules adopt a dual-support structure, with one end connected to one side of the main arm via a cross roller bearing and the other end connected to the other side of the main arm via a deep groove ball bearing, which can improve the overall rigidity of the robotic arm.

[0087] The J4 joint module, which controls the rotation of the wrist structure, is rear-mounted and fixed. It controls the pitch movement of the wrist relative to the forearm through a double-link mechanism, making the wrist structure more compact. It also allows the center of gravity of the robotic arm to be positioned rearward, reducing the load torque requirements of the J2 and J3 joint modules.

[0088] Modular design, highly adaptable. The modular design of the joint modules, base, and mounting flanges allows for adaptation to other operating scenarios.

[0089] The preferred embodiment of the present invention is as follows: like Figures 1 to 13 As shown in the figure, this embodiment discloses a multi-degree-of-freedom robotic arm operating mechanism for sanitation vehicles. It is mainly used in unmanned sanitation sweeping vehicles to clean up garbage in areas such as corners, curbs, and around obstacles that cannot be reached by the vehicle's main sweeping mechanism. It collects scattered garbage into the main sweeping operation range of the vehicle, thereby improving the overall sweeping coverage of the vehicle.

[0090] The multi-degree-of-freedom robotic arm operating mechanism of the sanitation vehicle consists of three main parts: a five-degree-of-freedom robotic arm 1, a gravity compensation mechanism 2, and a sweeping disc mechanism 3. The five-degree-of-freedom robotic arm 1 is installed and fixed as a whole by relying on the base 11. The base 11 serves as the mounting base for the entire robotic arm and can be directly fixed to the sanitation vehicle body or mounted on the swing arm structure at the front of the vehicle body. The base 11 bears the weight of the entire robotic arm, gravity compensation mechanism, and sweeping disc mechanism, as well as the impact load during operation. Therefore, the base 11 adopts a thickened cast aluminum welded structure. The mounting surface of the base is reserved with multiple sets of positioning pin holes and bolt holes to ensure assembly positioning accuracy. During operation, it can suppress the vibration of the base itself and ensure the accuracy of the end-effector position.

[0091] The waist section 12 is equipped with a J1 joint module 17 and a J2 joint module 18. The J1 joint module 17 is connected to the base 11 and the waist section 12 respectively, realizing the rotational movement of the waist section 12 relative to the base 11. The base is a vertical structure, and the bottom of the base is provided with a fixing flange structure. Each corner of the fixing flange structure is located on the outside of the base, and fixing holes are provided at the corners for easy installation and fixing.

[0092] The J2 joint module 18 connects the waist 12 to the front end of the upper arm 13, driving the upper arm 13 to complete the up-and-down arm swinging motion relative to the waist 12; it extends out from one side of the waist and the protrusion is connected to the lower end of the upper arm, with a compact structure; the end of the upper arm 13 is connected to the J3 joint module 19 located at the front of the forearm 14, and the output end of the J3 joint module 19 is fixedly connected to the forearm 14, driving the forearm 14 to swing up and down relative to the upper arm 13. The J4 joint module 110 is built into the middle of the forearm 14, not located at the wrist end of the forearm, and adopts a rear-mounted arrangement. The output end of the J4 joint module 110 is connected to the linkage transmission assembly, and the linkage mechanism drives the J5 joint module 111 located at the end of the forearm 14 to achieve pitching motion; the J5 joint module 111 is assembled on the wrist 15, and the end mounting flange 16 is locked and fixed to the output end of the J5 joint module 111.

[0093] In this embodiment, joint modules J1 (17), J2 (18), J3 (19), J4 (110), and J5 (111) are all planetary integrated joint modules with a relatively small transmission ratio. This configuration satisfies the positioning accuracy requirements of the end-effector sweeping mechanism while providing good counter-drive capability. When the sweeping mechanism collides with obstacles such as steps or stones, the joints can passively rotate in the opposite direction to buffer external impacts, preventing damage to the joints and arm structure from rigid impacts, and reducing the impact transmitted to the sanitation vehicle body. Joint module J1 (17) controls the waist 12 to rotate relative to the base 11, achieving overall horizontal rotation of the robotic arm; joint module J2 (18) drives the upper arm 13 to complete the up-and-down swing; and joint module J3 (19) drives the forearm 14 to swing relative to the upper arm 13. The three joint modules J1, J2, and J3 work together to control the position of the end-mounted flange 16 of the robotic arm in the three-dimensional space of X, Y, and Z. This adjusts the working point of the sweeping mechanism 3, allowing the sweeping disc to reach gaps and curb edges around the vehicle body that cannot be reached by conventional sweeping discs.

[0094] The J4 joint module 110 controls the pitch movement of the wrist 15 relative to the forearm 14, while the J5 joint module 111 controls the roll movement of the end-mounted flange 16. Through the coordinated adjustment of the J4 and J5 joint modules 111, the sweeping disc mechanism 3 mounted on the end-mounted flange 16 maintains a preset pitch and roll angle relative to the ground. Even on slopes or uneven surfaces, the sweeping disc's bottom surface remains as close to the ground as possible, preventing one side from being suspended or subjected to excessive local pressure. The J4 joint module 110 is integrated into the middle of the forearm 14, working in conjunction with a linkage mechanism to drive the wrist pitch. This shifts the weight of the driving components towards the middle of the forearm, achieving a rearward center of gravity, reducing the weight of the wrist end-mounted flange, and lowering the continuous load on the J2 and J3 joint modules. This helps reduce joint power consumption and also reduces the overall size of the wrist, decreasing the probability of friction or interference with surrounding obstacles during operation.

[0095] The main function of the gravity compensation mechanism 2 is to compensate for the self-weight of the five-degree-of-freedom robotic arm 1 and the end load brought by the sweeping mechanism 3, thereby reducing the load borne by the J2 joint module 18. In this embodiment, the gravity compensation mechanism 2 is a spring-pull rod mechanism 23. The two ends of the spring-pull rod mechanism 23 are respectively equipped with hinge I 21 and hinge II 22. One end is hinged to the waist 12 above the waist via hinge II 22, and the other end is hinged to the end of the upper arm 13 via hinge I 21. The spring-pull rod mechanism 23 includes a tension spring, an adjusting rod, a spring stop, an adjusting nut, and hinged joints at both ends. The adjusting rod passes through the tension spring. The operator can adjust the pre-tension of the tension spring by adjusting the adjusting nut to adapt to sweeping mechanisms of different weights and to adjust the optimal compensation torque. Since the lower end of the upper arm is connected to the extension of the waist, the lower end of the gravity compensation mechanism is connected to the top of the waist, and the upper end of the gravity compensation mechanism is connected to the end of the upper arm, a triangular structure is formed, which is stable and reliable.

[0096] When the robotic arm 13 is in a vertical position, its center of gravity is close to the rotation center of the J2 joint module 18, resulting in a small eccentricity and a small extension of the spring-pull rod mechanism 23, leading to a smaller output compensating torque. As the arm 13 gradually rotates towards a horizontal position, the gravitational eccentricity generated by the arm's own weight and the end effector's sweeping load increases. The hinge I 21 at the end of the arm 13 swings with the arm, further extending the spring-pull rod mechanism 23. This increases the spring tension and outputs a larger compensating torque, offsetting most of the overturning torque generated by its own weight and significantly reducing the load torque required by the J2 joint module 18. This reduces heat generation in the J2 joint module 18, lowering the overall energy consumption of the robotic arm. Furthermore, smaller J2 joint modules can be selected during the selection phase, reducing overall machine costs. The gravity compensation mechanism 2 is integrally arranged at the waist and inside the upper arm, with a compact overall structure. Throughout the entire process of the robotic arm driving the upper arm to rotate around the waist 12, the spring-loaded lever mechanism 23 will not protrude outwards, will not encroach on the external space surrounding the robotic arm, and will not interfere with the movement of the vehicle body or external obstacles. It should be noted that the spring-loaded lever mechanism 23 is the preferred option in this embodiment. In other embodiments, the gravity compensation mechanism 2 can be replaced with other elastic compensation structures such as gas springs or disc springs, all of which can achieve the effect of gravity torque compensation.

[0097] The sweeping mechanism 3 consists of a six-dimensional torque sensor 31, a sweeping disc bracket 32, a motor 33, a reducer 34, a sweeping disc mounting flange 35, and a sweeping disc 36. The sweeping mechanism 3 is assembled on the end mounting flange 16 of the five-degree-of-freedom robotic arm 1. The sweeping disc bracket 32 ​​has a connecting plate; the six-dimensional torque sensor 31 is mounted on one side of the connecting plate, and the motor 33 and reducer 34 are arranged on the other side. The motor 33 and reducer 34 are integrated into a single drive assembly, resulting in high structural integration and facilitating assembly and debugging. The six-dimensional torque sensor 31 is mounted between the end mounting flange 16 and the sweeping disc bracket 32, serving the dual purpose of force signal acquisition and component connection. The output end of the integrated drive assembly is connected to the sweeping disc mounting flange 35 via a transmission connection. The sweeping disc 36 is fixedly mounted on the lower end of the sweeping disc mounting flange 35 and is driven by the motor 33 through the reducer 34 to rotate and complete the cleaning operation.

[0098] Joint modules J1 (17), J2 (18), and J3 (19) work together to control the sweeping disc 36's position in the X, Y, and Z three-dimensional space. Joint modules J4 (110) and J5 (111) work together to control the sweeping disc 36's pitch and roll posture relative to the ground. The sanitation vehicle's onboard controller has a built-in cleaning strategy that outputs control commands based on the distribution of garbage in the area to be cleaned, setting the sweeping position, rotation direction, rotation speed, and sweeping posture angle of the sweeping disc 36. The six-dimensional torque sensor 31 can collect multi-dimensional force and torque signals in real time during the sweeping operation, sensing changes in contact force caused by ground undulations and protruding obstacles. The signal output terminal of the six-dimensional torque sensor 31 is electrically connected to the robotic arm controller. The robotic arm controller incorporates an impedance control algorithm to adjust the output of each joint of the robotic arm in real time based on the torque data fed back by the sensor, dynamically changing the height of the sweeping disc 36 relative to the ground and its contact pressure with the ground.

[0099] When the road surface is uneven, and the pressure of the sweeping disc on the ground exceeds a set threshold, the controller controls the robotic arm to raise its end to reduce contact pressure, prevent excessive wear on the sweeping disc, and buffer impact loads to protect the joints and sweeping disc components. When the road surface is sunken, and the contact pressure of the sweeping disc is insufficient, the controller controls the end of the robotic arm to press down appropriately to ensure that the sweeping disc brushes effectively adhere to the ground, ensuring effective garbage collection. Relying on this force feedback closed-loop control, the sweeping disc mechanism 3 can adapt well to complex road surfaces such as potholes, curbs, and gravel, without requiring high-precision terrain modeling of the environment in advance, making it highly suitable for autonomous operation scenarios of unmanned sanitation vehicles.

[0100] In actual operation, the base 11 is fixed to the sanitation vehicle body. The robotic arm moves the sweeping disc mechanism 3 to the cleaning area that the vehicle body cannot reach, according to the cleaning task, using the J1 and J3 joints. The J4 and J5 joints adjust the sweeping disc posture so that the bottom surface of the sweeping disc is in contact with the ground. The gravity compensation mechanism 2 counteracts the self-weight load of the arm body in real time, reducing the load on the J2 joint. The six-dimensional torque sensor 31 collects the contact force in real time, and the impedance control dynamically adjusts the pressure of the sweeping disc on the ground. The motor drives the sweeping disc to rotate, sweeping the garbage in the corners to the main cleaning area, thus completing the cleaning operation.

[0101] The above description is merely an illustration of preferred embodiments of the present invention, and the above technical features can be arbitrarily combined to form multiple embodiments of the present invention.

[0102] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the concept and technical solution of the present invention, or the direct application of the concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A robotic arm operating mechanism, comprising a robotic arm (1) and a sweeping mechanism (3), characterized in that: The robotic arm (1) is a five-degree-of-freedom robotic arm; the five-degree-of-freedom robotic arm includes a base (11), a waist (12), an upper arm (13), a lower arm (14), a wrist (15), an end-mounted flange (16), and joint modules J1, J2, J3, J4, and J5; the sweeping mechanism is connected to the end-mounted flange; the J1 joint module (17) is used to drive the waist to rotate relative to the base; the J2 joint module (18) is used to drive the upper arm to swing up and down relative to the waist; the J3 joint module (19) is used to drive the lower arm to swing up and down relative to the upper arm. The J4 joint module (110) is used to drive the wrist to perform pitching motion relative to the forearm; the J5 joint module (111) is used to drive the end-mounted flange to perform rolling motion.

2. The robotic arm working mechanism as described in claim 1, characterized in that: It also includes a gravity compensation mechanism (2), the upper end of which is hinged to the upper arm (13), and the lower end of which is hinged to the waist (12).

3. The robotic arm working mechanism as described in claim 2, characterized in that: The gravity compensation mechanism (2) is a spring rod structure, with one end of the spring rod structure hinged to the upper part of the waist and the other end of the spring rod structure hinged to the end of the upper arm.

4. The robotic arm working mechanism as described in claim 1, characterized in that: The joint structures on the upper arm (13) and the lower arm (14) both adopt a double support structure; the double support structure is a pair of bearing structures set on both sides of the joint structure.

5. The robotic arm working mechanism as described in claim 1, characterized in that: It also includes a six-dimensional torque sensor (31) for sensing the ground undulation, the six-dimensional torque sensor being connected between the end mounting flange (16) and the sweeping disc mechanism (3).

6. The robotic arm working mechanism as described in claim 5, characterized in that: The sweeping mechanism (3) includes a sweeping bracket (32), a drive structure, a sweeping mounting flange (35), and a sweeping disc (36). The drive structure is located on the sweeping bracket and connected to the sweeping mounting flange, and the sweeping disc is installed on the sweeping mounting flange. A connecting plate is provided on the sweeping bracket (32), a six-dimensional torque sensor (31) is installed on one side of the connecting plate, and the drive structure is located on the other side of the connecting plate.

7. The robotic arm working mechanism as described in claim 6, characterized in that: It also includes a robotic arm controller for adjusting the height of the robotic arm end-effector relative to the ground and the contact pressure in real time, the robotic arm controller being connected to a six-dimensional torque sensor (31).

8. The robotic arm working mechanism as described in claim 1, characterized in that: All of the aforementioned joint modules adopt planetary integrated joint modules; the planetary integrated joint modules are planetary integrated structures with anti-drag capabilities.

9. A cleaning assembly, characterized in that: The robotic arm operating mechanism as described in any one of claims 1 to 8 is provided with a mounting and fixing structure on the base (11).

10. A sanitation vehicle, comprising a vehicle body, characterized in that: It also includes the sweeping assembly as described in claim 9, wherein the sweeping assembly is mounted on the vehicle body via a mounting and fixing structure; the front of the vehicle body is provided with a swing arm structure, and the base of the robotic arm working mechanism is fixed on the swing arm structure.

Images