Force control universal floating polishing device for robot and control method thereof

Abstract

The present application relates to a kind of force control universal floating polishing device for robot and control method thereof, belong to force control polishing device and robot intelligent control technical field.The sleeve of the polishing device and polishing motor are connected with the shell, cover, adjusting wheel, support wheel installed together by rubber spring, the six degrees of freedom of polishing head datum point are limited by rubber spring;By adjusting the rotation angle of control motor, the multidimensional movement of polishing head is regulated, and force control universal floating polishing is realized.The control method establishes operation model, utilizes processing experiment to select rubber spring, and optimizes the rotation angle of control motor when polishing head datum point reaches different positions, improves control precision, enhances polishing effect, improves processing efficiency, adapts to different models of workpiece blank, satisfies the polishing effect of different structural characteristics;During polishing processing, only according to the position of polishing head, the rotation angle of stored control motor can be called, i.e.active force control and passive force control are combined.

Description

Technical Field

[0001] This invention relates to a force-controlled grinding device for robots and its control method, belonging to the fields of force-controlled grinding devices and intelligent robot control technology. Background Technology

[0002] The tolerances of the workpiece blanks are relatively large, generally between 0.1mm and 2mm, and they also have gates, flash, burrs, parting lines, etc., requiring grinding. Grinding workpiece blanks generates noise and dust, causing serious environmental pollution. With the rapid development of industrial robots and artificial intelligence technologies, the "robot replacement" wave has swept through the manufacturing industry, and robots are now widely used to replace manual labor for workpiece blank grinding operations.

[0003] Due to the large tolerances of the workpiece blank, existing grinding robots require force control to ensure sufficient contact between the grinding head and the workpiece and to obtain the desired grinding effect. Patent application number 202211626145.3 discloses a three-dimensional force-controlled floating grinding device, including a first frame, a Z-axis assembly, a Y-axis assembly, and an X-axis assembly. The Z-axis assembly is driven by a first motor and connected to a first tension / compression sensor. The Y-axis assembly includes a second frame, a second tension / compression sensor, and a Y-axis hydraulic cylinder. The X-axis assembly includes a third frame, a third tension / compression sensor, and an X-axis hydraulic cylinder. This device enables multi-dimensional constant-force grinding, improving grinding quality. Patent application number 202310653228.X discloses an electromagnetic direct-drive robot radial floating grinding end effector, including a stator, a mover, and a connecting mechanism. It utilizes the Ampere force principle to generate a driving torque, driving the mover to rotate, enabling the end effector to float radially along the surface of the workpiece. This improves force control accuracy and response speed. Applied to grinding robots, it can perform high-precision two-degree-of-freedom grinding on workpieces with different surface shapes, improving polishing quality, accuracy, and efficiency. Patent application number 201710811731.8 discloses a radial constant-force floating device, including a cylinder and a piston. The cylinder is sleeved outside the piston and forms an air chamber with it. An air inlet is opened on the cylinder and connected to the air chamber; this keeps the grinding pressure constant and can absorb deviations between the processing path and the workpiece's curve. It is evident that existing workpiece grinding robots generally install force control devices, utilizing hydraulic, electromagnetic, and pneumatic principles for force control.

[0004] To achieve multi-dimensional force control, researchers have conducted studies and proposed various technical solutions. Patent application number 201610963759.9 discloses a flexible grinding device, including a power source unit, an output execution unit, and a flexible shaft, further including an axial floating unit and / or a radial floating unit to achieve axial and / or radial floating; the axial and / or radial floating units absorb the curve deviation between the processing path and the processed material; since the flexible shaft can transmit greater power, it can grind burrs, gates, and welds, increasing the processing range. Patent application number 202310622022.0 discloses an XYZ three-axis floating force control device, including an outer housing, inside which an inner body is fixedly installed; the outer surface of the inner body is circumferentially arranged with multiple sensing processing components to improve the precise control of the contact force between the grinding tool and the casting, ensuring control of the grinding cutting force. Currently, various floating grinding technologies exist. For example, utility model patent application number 202223140280.5 discloses a floating grinding head for industrial robots, including a tool holder, a fixed handle below the tool holder, and a flap wheel chuck at the lower end of the fixed handle; a floating guide rod is set between the fixed handle and the flap wheel chuck; the floating power is provided by a spring, with strong and stable elasticity; it reduces the workload of teaching the robot to automatically grind, effectively reducing the teaching difficulty; the floating distance is adjustable, which can increase the service life of the flaps (grinding consumables) and reduce grinding costs; the structure is simple and the consumables are easy to replace. Invention patent application number 202110921558.3 ​​discloses a floating tool holder, including a tool holder, a fixed shell, and a floating tool bar; it changes position according to the workpiece blank, automatically avoiding obstacles to remove burrs or process chamfers, with a simple structure and good performance.

[0005] It is evident that existing multi-dimensional force control in grinding robots is active, structurally complex, widely applicable, and offers high control precision but also incurs high costs. In contrast, existing floating grinding technologies generally employ floating tool holders, which are passive, relatively simple in structure, and offer lower control precision but also lower costs. This clearly presents a technical contradiction: "active force control is complex, requiring high precision and cost; passive force control is simple, requiring low precision and cost." With the rapid development and application of next-generation information technologies such as artificial intelligence, the Internet of Things, and cloud computing, the intelligence level of grinding robots is continuously improving. Furthermore, specific manufacturing enterprises often employ grinding robots designed for specific scenarios due to the limited variety of workpiece blanks. Therefore, further research and improvement of robot force-controlled floating grinding devices and their control methods are necessary. Summary of the Invention

[0006] The purpose of this invention is to provide a force-controlled omnidirectional floating grinding device for robots and its control method. It improves the structure of the grinding device by using rubber springs to achieve force-controlled omnidirectional floating grinding; it utilizes a motor for intelligent control, improving adjustability and control precision, enhancing grinding effect, and increasing processing efficiency; it combines active force control and passive force control, resolving the technical contradiction of "active force control being complex, requiring high precision and cost; passive force control being simple, requiring low precision and cost." The specific technical solution of this invention is as follows.

[0007] A force-controlled omnidirectional floating grinding device for robots includes a grinding head, a housing, a rubber spring, a sleeve, a grinding motor, a control motor, an end cap, a bushing, and a protective sleeve. The device is mounted on the robot's manipulator via the housing, and the grinding head is mounted via the bushing. Omnidirectional floating force control is achieved through the rubber spring and the control motor, enabling force-controlled omnidirectional floating grinding of workpiece blanks. The housing comprises a cylindrical, mutually perpendicular shell and a mounting cylinder, which is mounted on the robot's manipulator. An adjusting wheel and a support wheel are mounted on the housing. The adjusting wheel presses against the upper end of the rubber spring, and the support wheel engages with the adjusting wheel to support the adjusting wheel and adjust its rotation angle, thereby adjusting and limiting the lateral position of the upper end of the rubber spring and the upper part of the sleeve.

[0008] The adjusting wheel includes a circular eccentric through hole, through which the sleeve passes at its upper part. The adjusting wheel can rotate relative to the sleeve, allowing it to adjust and limit the lateral position of the upper part of the sleeve. The housing is a vertical cylindrical structure with a constricted opening at its lower end, allowing the rubber spring to extend and retract freely. The constricted opening is a longitudinal non-circular through hole that engages with the lower outer surface of the rubber spring to limit the lateral position of the rubber spring and the sleeve at the lower part and prevent the rubber spring from rotating relative to the housing. The rubber spring is a longitudinal straight cylindrical structure with an inner hole through which the sleeve passes. The rubber spring abuts against the adjusting wheel at its upper end and against the end cap at its lower end, bearing a compression effect. The sleeve is a longitudinal cylindrical structure with an inner hole through which the bushing passes.

[0009] The grinding motor is mounted on the upper end of the sleeve. The grinding motor includes a spindle, which is fastened to a bushing to drive the grinding head for force-controlled omnidirectional floating grinding. The control motor is mounted on the housing; the control motor is connected to the support wheel, drives the support wheel, and drives and adjusts the rotation angle of the adjustment wheel. The end cap is an upward-facing circular cap structure with a through hole in the center, which is used to mount it to the lower end of the sleeve, preventing the end cap from rotating relative to the sleeve.

[0010] The grinding head includes a head and a shank. The head has hard abrasive or cutting teeth on its surface. The shank is a straight rod structure used for clamping and is also called a handle. When the grinding head has cutting teeth on its head, it is also called a file. The housing houses a rubber spring and a sleeve. The housing is fitted with a cover, an adjusting wheel, and a support wheel. The adjusting wheel presses the upper end of the rubber spring and adjusts its lateral position. The support wheel engages with the adjusting wheel to support the adjusting wheel and adjust its rotation angle, thereby adjusting and limiting the lateral position of the upper end of the rubber spring and the upper part of the sleeve relative to the housing.

[0011] The housing is an upright cylindrical structure, tapering inward at the bottom and containing a circumferential groove on the lower part of its outer surface, through which the protective sleeve is fixedly installed. The housing tapers inward at the lower end to form a constricted opening, allowing the rubber spring to extend and retract freely. The housing protrudes outward at the upper end to form a flat flange, which includes a longitudinal shaft hole and a fastening hole. A support wheel is mounted through the shaft hole, and a fastener passes through the fastening hole to securely install the protective cover onto the housing.

[0012] The cover is an oblong cover with its outer edge bent downwards to form a lower edge, presenting a cover-like structure. The lower edge abuts against the upper surface of the outer edge of the housing flange, achieving a secure installation of the cover on the housing. The cover includes a through hole at a lateral position corresponding to the fastening hole of the housing. This through hole, along with the fastening hole of the housing, allows a fastener to pass through, ensuring a secure installation of the cover on the housing. The cover includes a longitudinally penetrating central hole in its middle section. A sleeve passes through this central hole, allowing the housing to accommodate the sleeve and preventing interference. The central hole of the cover is circular, coaxial with and parallel to the adjusting wheel. The lower surface of the edge of the central hole of the cover includes an annular groove, which provides a dynamic seal relative to the adjusting wheel. Furthermore, the cover includes a shaft hole at a lateral position corresponding to the shaft hole of the housing, through which a support wheel is mounted, providing support and allowing relative rotation of the support wheel.

[0013] The adjusting wheel is a disc-shaped gear with teeth on its outer circumference. These teeth mesh with a support wheel, and a circular sealing ring is fixedly installed on its upper surface. The sealing ring is a circular structure, coaxial with the adjusting wheel, and elastic. It engages with the annular groove of the cover, allowing the adjusting wheel to abut against the cover via the sealing ring, achieving a dynamic seal and preventing the intrusion of chips and dust. The adjusting wheel includes a circular eccentric through-hole, allowing the sleeve to pass through it at the top and rotate relative to it. This allows the adjusting wheel to adjust and limit the lateral position of the upper part of the sleeve by rotation. Preferably, the eccentric through-hole of the adjusting wheel has a larger diameter at its lower end, forming a flared opening. This flared opening engages with the upper end of the rubber spring to ensure a uniform clearance fit between the sleeve and the eccentric through-hole of the adjusting wheel. This allows the sleeve to be connected to the adjusting wheel at the top via the rubber spring, preventing vibration and noise.

[0014] The support wheel is a disc-shaped gear with a longitudinal axle at its center and teeth on its outer circumference. These teeth mesh with the teeth of the adjusting wheel to support and define the lateral position of the adjusting wheel, allowing the adjusting wheel to adjust and define the lateral position of the upper part of the sleeve. The axle of the support wheel is mounted in the shaft holes of the cover and the housing, providing support and enabling relative rotation of the support wheel. Furthermore, there are at least three support wheels to define the lateral position of the adjusting wheel, with one serving as the driving wheel and the others as driven wheels. The driving support wheel drives the adjusting wheel to rotate, thereby adjusting the lateral position of the upper part of the sleeve. The axle of the driving support wheel is connected to a control motor to obtain driving torque, driving and adjusting the rotation angle of the adjusting wheel to adjust and define the lateral position of the upper part of the sleeve. The groove surrounds the lower part of the outer surface of the housing, forming an annular shape and concave inward, to facilitate the fixed installation of the cover and prevent the cover from loosening or falling off.

[0015] The housing has a longitudinal circular bore located on the upper surface of the flange, which mates with the axle of the support wheel to provide support. The support wheel, used as a driven wheel, has a blind bore. The support wheel, used as a driving wheel, has a through bore that extends vertically through the flange of the housing, allowing the axle of the driving wheel to connect to the control motor.

[0016] The constriction is a longitudinal, non-circular through hole located at the lower end of the housing, passing through the lower part of the rubber spring and engaging with the lower part of the outer surface of the rubber spring, allowing the rubber spring to pass through the constriction and freely extend and retract, thereby limiting the lateral position of the rubber spring and the sleeve at the lower part and preventing the rubber spring from rotating relative to the housing.

[0017] The fastening hole of the housing extends longitudinally through the flange of the housing to facilitate the passage of fasteners and achieve the fastening installation of the cover on the housing. When the fasteners are bolts and nuts, the fastening hole is a smooth hole; when the fasteners are screws, the fastening hole is a threaded hole; the threaded hole includes internal threads, and fastening is achieved by engaging the internal threads with the screw.

[0018] The mounting cylinder is a horizontal cylindrical shape, which is fastened to the outer surface of the housing at its right end to form a single unit. At its left end, it includes a flange, which is fastened to the robot's manipulator, allowing the grinding device to be mounted on the robot's manipulator. The mounting cylinder has a through hole on its flange, through which fasteners pass to achieve the fastening connection with the robot's manipulator.

[0019] The rubber spring has a longitudinal cylindrical structure with a circular inner hole through which it passes. The upper end of the rubber spring abuts against the lower surface of the adjusting wheel, and the lower end abuts against the upper surface of the end cap, thus bearing compression. Preferably, the rubber spring has an upward-protruding lip at the upper end of the inner hole, which engages with the gap between the sleeve and the flared opening at the lower end of the eccentric through-hole of the adjusting wheel, ensuring a uniform and consistent fit to prevent vibration and noise.

[0020] The rubber spring contains a cylindrical helical steel wire internally, with rubber wrapped around the wire to enhance stability and load-bearing capacity; therefore, it is also called a composite spring. The outer surface of the rubber spring includes evenly distributed circumferential chamfered surfaces, giving it a non-circular cross-section. The lower part of the outer surface of the rubber spring engages with a constricted opening at the lower end of the housing, allowing the rubber spring to extend freely and constrain its lateral position relative to the housing, thus limiting the lateral position of the rubber spring and sleeve at the lower part. The lower end face of the rubber spring includes an axial groove, which engages with an end cap to prevent rotation of the rubber spring relative to the end cap.

[0021] The sleeve is a longitudinal cylindrical structure with an inner bore through which the bushing passes, and is bent outward at the upper end to form a flange. The flange of the sleeve has a longitudinal through hole through which a fastener passes, securing it to the grinding motor. This allows the grinding motor to be mounted on the upper end of the sleeve, achieving both fixation and support. A rubber ring is fixedly installed on the lower surface of the sleeve's flange, and this rubber ring contacts the upper surface of the adjusting wheel to prevent impact, noise, and damage. The rubber ring is an annular structure with elasticity, providing a cushioning effect. Furthermore, the lower end of the sleeve's outer surface includes a threaded section, which is used to install the end cap, providing fixation and support for the end cap.

[0022] The grinding motor is mounted downwards and includes a spindle and a mounting base. The spindle is securely connected to a bushing to drive a grinding head mounted on the lower end of the bushing for force-controlled omnidirectional floating grinding. The spindle is a longitudinal round rod with external threads at its lower end, which are used to securely connect to the bushing, allowing the bushing to be mounted on the spindle of the grinding motor at its upper end. The mounting base is a flat, disc-shaped structure with a longitudinal through-hole. Fasteners pass through this through-hole and the through-hole of the sleeve flange, securing the grinding motor to the flange of the sleeve. This allows the grinding motor to be mounted on the upper end of the sleeve using the mounting base, achieving both fixation and support.

[0023] The control motor includes an upward-facing main shaft, which is mounted upward-facing on the lower surface of the upper flange of the housing. The main shaft of the control motor is connected to the axle of the support wheel, which serves as the drive wheel, driving the support wheel and adjusting the rotation angle of the adjustment wheel.

[0024] The end cap is an upward-facing circular structure with an outer upper edge formed by bending upwards at its outer edge. Its upper surface includes radial ribs that engage with the axial groove at the lower end of the rubber spring, preventing the rubber spring from rotating relative to the end cap. The ribs are radially straight strips that connect to the outer upper edge of the end cap at their outer ends, increasing structural strength. The diameter of the end cap is larger than the circumcircle diameter of the constricted cross-section of the housing, preventing the end cap from entering the housing through the constriction and avoiding excessive compression and damage to the rubber spring. The end cap has a through hole at its center and protrudes downwards along the edge of the through hole, forming an inner lower edge. A transverse threaded hole is included on the inner surface of the through hole. The end cap has internal threads on the inner surface of the through hole, which engage with the threaded lower end of the sleeve, allowing the end cap to be installed on the lower end of the sleeve via the through hole. The screw hole includes an internal thread, and a screw is installed using the internal thread so that the screw abuts against the sleeve, which has a locking function and prevents the end cap from rotating relative to the sleeve, thereby preventing the end cap from loosening and falling off.

[0025] The bushing is a longitudinal cylindrical structure with an inner hole at its center. An internal thread is present at the upper end of the inner hole, engaging with the external thread of the grinding motor's spindle via this internal thread, allowing the bushing to be mounted on the upper end of the grinding motor's spindle. The lower end of the bushing's outer surface has an external thread, and the lower end of the inner hole has a tapered hole. A spring clip is mounted through the tapered hole, and a nut is mounted through the external thread. The spring clip clamps the shank of the grinding head, allowing the grinding head to be mounted on the lower end of the bushing. The tapered hole is a conical inner hole with a diameter larger at the lower end than at the upper end, communicating with the inner hole of the bushing at the upper end. The spring clip has a conical cylindrical structure with a conical outer surface and an axial inner hole; it is also called a spring collet. It has radial grooves on its cylindrical wall, allowing for elastic inward and outward expansion. The conical outer surface engages with the tapered hole of the bushing, and the inner hole is used to insert and clamp the shank of the grinding head, allowing the grinding head to be mounted on the lower end of the bushing. The nut includes a threaded hole, also known as a tool holder nut or collet nut. The inner surface of the threaded hole has an internal thread. The internal thread engages with the external thread of the bushing, driving the spring collet to move axially and elastically retract, so that the spring collet clamps and fixes the handle of the grinding head.

[0026] The sheath is a longitudinally tapered structure, with a circular upper opening and a circular lower opening. The diameter of the upper opening is larger than that of the lower opening, forming a longitudinally tapered structure. The upper opening is turned outward, giving the sheath a flange at the upper end, and a clamp is installed below the flange to prevent the clamp from coming off. The sheath inserts into the outer shell through its upper opening, and by tightening the clamp, the upper end of the sheath engages with a groove in the shell, ensuring the sheath is properly installed on the outer shell and preventing it from loosening or falling off. The lower end of the sheath tapers inward, allowing the inner lower edge of the end cap to protrude through its lower opening. The outer surface of the sheath is corrugated, allowing for longitudinal elastic expansion and contraction. This allows the sheath to press against the lower surface of the end cap at its lower end, preventing the intrusion of chips and dust, ensuring the rubber spring can freely expand and contract, thus providing protection.

[0027] A smart omnidirectional floating control method is provided for a robot equipped with the grinding device described in this invention to perform omnidirectional floating force-controlled grinding. The control method establishes and stores the following computational model in the robot's control system, preferably before leaving the factory.

[0028] First, the grinding device is manufactured to order, with the workpiece blanks that the customer needs to grind numbered and denoted as follows: m When the robot performs grinding, it uses the grinding head as a reference for point-to-point control. Therefore, the coordinates of the reference point of the grinding head are marked as ( x, y, z );in, x The x-axis is...y The vertical axis is , z The vertical axis represents the workpiece blank model. The workpiece blank model refers to a classification based on its structural characteristics, forming method, specifications, and dimensions; therefore, workpiece blanks with the same structural characteristics, forming method, specifications, and dimensions share the same number. m The specifications refer to the tolerances, materials, and surface quality of the workpiece blank; the dimensions refer to the dimensional characteristics of the workpiece blank, such as length, width, thickness, and diameter. The control motor of the grinding device can drive and adjust the rotation angle of the adjusting wheel, and through the eccentric through-hole of the adjusting wheel, adjust and limit the lateral position of the upper part of the sleeve, thereby controlling the lateral position of the grinding head reference point; therefore, the rotation angle of the control motor is denoted as... θ During the grinding experiment, the grinding device uses a mounting sleeve on the outer shell to install a force sensor, which is then mounted on the robot's manipulator. The cutting force obtained by the force sensor is recorded as... f ; Storage space is allocated in the storage medium of the robot control system to record and store data. θ ( i, m, x, y, z )and f ( i, m, x, y, z );in, i Coordinate sequence number; θ ( i, m, x, y, z The grinding process number is m During the workpiece blanking process, the reference point of the grinding head reaches the first... i The coordinates are ( x, y, z When the position is ), the initial rotation angle of the control motor is 0°; f ( i, m, x, y, z The grinding process number is m During the workpiece blanking process, the reference point of the grinding head reaches the first... i The coordinates are ( x, y, z The cutting force value obtained by the force sensor at the position of ).

[0029] Second, regarding the number m Write a machining program for the workpiece blank to obtain the machining path and related machining parameters, including at least the coordinate sequence of the movement of the grinding head reference point during machining. i , m , x , y , z The machining program is stored in the storage medium of the robot control system. To avoid programming errors, a trial cut on the first piece is preferred.

[0030] Third, a robot equipped with the aforementioned grinding device is used to target the part numbered [number missing]. m A grinding experiment was conducted on the workpiece blank to observe and record the grinding effect. f ( i , m , x , y , z The maximum and minimum values ​​of the cutting force are obtained and denoted as follows: maxf ( m )and minf ( m ).

[0031] Fourth, a robot equipped with the aforementioned grinding device is used to target the part numbered [number missing]. m The workpiece blank underwent multiple grinding and machining experiments to adjust... θ ( i , m , x , y , z Replace the rubber spring to reduce ( maxf ( m ) - minf ( m The value of the cutting force is adjusted to improve control precision, enhance grinding effect, and increase processing efficiency. When the cutting force is insufficient, it is preferable to replace the rubber spring with one that has a larger elastic modulus and a larger free length. A rubber spring with a larger elastic modulus can generate greater elastic force when subjected to compression deformation; a rubber spring with a larger free length can generate greater preload after installation.

[0032] The control method includes the following steps: The first step involves the robot installing the polishing device targeting the part numbered [number missing]. m The workpiece blank is ground. Before the grinding process begins, the robot's control system is started and initialized, and settings are configured. i The initial value is 0; set the variable tempx , tempy and tempz And let their initial values ​​be {0, m , x , y , z}middle x , y and z The value of ; the robot's control system issues a control command to adjust the rotation angle of the control motor to 0°.

[0033] The second step involves the robot targeting the numbered... m The workpiece blank is then subjected to grinding; the grinding motor is started.

[0034] Thirdly, the robot's control system controls the movement of the grinding head, and the reference point of the grinding head moves, its coordinates { x , y , z} changes; Determine if the grinding head reference point has reached the first... i There are coordinate points; if ( tempx==x and tempy==y and tempz= =z If the condition is true, then the destination has been reached; otherwise, the destination has not been reached.

[0035] Fourth step, if reached, then: The robot's control system issues a control command to adjust the rotation angle of the control motor to... θ ( i , m , x , y , z To ensure the required polishing effect and processing efficiency; i = i +1; variables tempx , tempy and tempz The values ​​are set to { i , m , x , y , z}middle x , y and z The value; Proceed to step three.

[0036] Fifth step: Determine if processing is complete. If not, proceed to step three. The grinding motor has stopped. Finish.

[0037] Supplementary Explanation: (1) The support wheel is mounted on the housing and the cover via its axle and is capable of relative rotation; there are at least three support wheels, whose teeth mesh with the teeth of the adjusting wheel to support and limit the lateral position of the adjusting wheel. The adjusting wheel includes an eccentric through hole, through which the sleeve passes and is clearance-fitted, and is capable of relative rotation. Therefore, the support wheel can adjust its rotation angle to drive the adjusting wheel to adjust its rotation angle, thereby adjusting and limiting the lateral position of the upper part of the sleeve relative to the housing.

[0038] (2) A sealing ring is fixedly installed on the upper surface of the adjusting wheel, and abuts against the protective cover installed on the housing to achieve dynamic sealing. The rubber spring passes through the sleeve through its inner hole, abutting against the lower surface of the adjusting wheel at its upper end and against the upper surface of the end cover at its lower end, and is subjected to compression. The end cover is installed at the lower end of the outer surface of the sleeve. The protective sleeve can elastically expand and contract longitudinally, and is installed on the housing of the outer shell at its upper end, and is pressed against the lower surface of the end cover at its lower end to prevent chips and dust from entering.

[0039] Therefore, the gap between the lower surface of the adjusting wheel and the upper surface of the flange of the housing effectively prevents contact and wear. Furthermore, during the grinding process, the grinding head mounted on the bushing contacts the workpiece blank located below the housing, generating a feed reaction force. This causes the rubber spring to compress, increasing the force exerted on the lower surface of the adjusting wheel due to contact. Therefore, the feed reaction force generated during the grinding process between the adjusting wheel and the workpiece blank ensures that the gap between the lower surface of the adjusting wheel and the upper surface of the flange of the housing is maintained, preventing contact and wear.

[0040] (3) The bushing is mounted on the spindle of the grinding motor at its upper end and on the grinding head at its lower end. The grinding motor is mounted on the upper end of the sleeve using the mounting base. The sleeve is a longitudinal cylindrical structure, with its inner hole passing through the bushing, and the end cap is mounted on the lower end of its outer surface; a flange is formed at the upper end of the sleeve, and a rubber ring is fixedly mounted on the lower surface of the flange, and contacts the adjusting wheel through the rubber ring. The rubber spring passes through the sleeve with its inner hole, abutting against the lower surface of the adjusting wheel at its upper end and against the upper surface of the end cap at its lower end, and bears the compression action. Therefore, during the grinding operation, the grinding head mounted on the bushing contacts the workpiece blank located below the housing, generating a feed reaction force, which can cause the rubber spring to compress, realizing floating grinding in the longitudinal movement dimension.

[0041] (4) The lower end of the housing has a longitudinal, non-circular through hole. The rubber spring engages with the lower end of the housing on its outer surface, allowing it to extend and retract freely through the opening, thus limiting the lateral position of the rubber spring and sleeve at the lower part and preventing relative rotation. The lower end of the housing is connected to the sleeve on which the grinding motor is mounted via the rubber spring. Additionally, the rubber spring has an axial groove on its lower end face, which engages with the end cap to prevent rotation of the rubber spring relative to the end cap. During the grinding process, the grinding head mounted on the bushing contacts the workpiece blank located below the housing, and the grinding motor rotates, generating a cutting torque. Therefore, the lower end of the housing can counteract the cutting torque through the rubber spring, causing the rubber spring to undergo torsional deformation, thus achieving floating grinding in the longitudinal rotation dimension.

[0042] (5) The lower end of the housing is narrowed and connected to the sleeve on which the grinding motor is mounted via the rubber spring; the upper part of the sleeve passes through the eccentric through hole of the adjusting wheel and is fitted with it with a clearance. Therefore, during the grinding operation, the housing can resist the lateral movement and lateral torsion of the grinding head caused by vibration at the lower end via the rubber spring; the housing restricts the six degrees of freedom of the grinding head reference point via the rubber spring, enabling force-controlled omnidirectional floating grinding.

[0043] (6) Preferably, the control method of the present invention establishes a calculation model for different types of workpiece blanks that need to be ground and processed by the customer before leaving the factory, and stores the coordinates of the reference point of the grinding head as ( x , y , z Control the motor's rotation angle at different positions; write machining programs, conduct grinding experiments, and adjust... θ ( i , m , x , y , z Replace the rubber spring to reduce ( maxf ( m ) - minf ( m The numerical value of )) improves control precision, enhances grinding effect, and increases processing efficiency. In the third step of the control method, it determines whether the reference point of the grinding head has reached the value stored in the computational model. i A coordinate point; if reached, then in step four, adjust the rotation angle of the control motor to... θ ( i , m , x , y , zTo ensure the required grinding effect and processing efficiency, the control method utilizes processing experiments to select the optimal rubber spring and optimize the rotation angle of the control motor when the grinding head reaches different positions. The optimal selection of the rubber spring generates optimal elasticity and preload to adapt to different types of workpiece blanks requiring grinding. Optimizing the rotation angle of the control motor when the grinding head reaches different positions allows for active adjustment of the cutting force in the lateral direction, achieving active force control and improving control accuracy; it also compensates for the shortcomings of the rubber spring, which has a small lateral float and insufficient passive force control in the lateral direction. The rubber spring has a longitudinal cylindrical structure; therefore, relative to the longitudinal direction, the grinding device has a small lateral float and insufficient passive force control in the lateral direction.

[0044] The control method utilizes processing experiments to optimize the rubber spring, adapting to different types of workpiece blanks requiring grinding. It also optimizes the rotation angle of the control motor when the grinding head reaches different positions, improving control accuracy and satisfying the grinding effect and processing efficiency requirements of different structural features of the workpiece blanks. During grinding, the rotation angle of the control motor stored in the computational model is called solely based on the grinding head position. Without using sensors for active force control, it achieves a combination of active and passive force control, resolving the technical contradiction of "complex active force control with high accuracy and cost; simple passive force control with low accuracy and cost." Since workpiece blanks of the same model have the same structural features, forming methods, specifications, and dimensions, the control method preferably establishes and stores the calculation model and writes and stores the processing program before leaving the factory. It achieves force-controlled omnidirectional floating grinding simply by selecting the best rubber spring and optimizing the rotation angle of the control motor when the grinding head reaches different positions, so as to adapt to the tolerance and surface quality changes of the workpiece blank in the processing area. Therefore, during the grinding process, the control method no longer uses sensors to regulate the movement path and processing parameters of the grinding head, and does not adopt closed-loop control, which greatly reduces the difficulty and cost of active force control and improves control accuracy.

[0045] The beneficial effects of the present invention are as follows: (1) The bushing of the present invention is installed on the main shaft of the grinding motor at the upper end and the grinding head is installed at the lower end; the grinding motor is installed on the upper end of the sleeve by means of the mounting seat; the sleeve is a longitudinal cylindrical structure, and the bushing passes through its inner hole, and the end cap is installed at the lower end of the outer surface; the rubber spring passes through the sleeve by means of its inner hole, and abuts against the lower surface of the adjusting wheel at the upper end and abuts against the upper surface of the end cap at the lower end, and bears the compression action.

[0046] Additionally, the support wheels are mounted to the housing and cover via their axles, allowing them to rotate relative to each other. There are at least three support wheels, whose teeth mesh with the teeth of the adjusting wheels to support and define the lateral position of the adjusting wheels. The adjusting wheel includes an eccentric through-hole, through which the sleeve passes and is clearance-fitted, allowing it to rotate relative to the adjusting wheel. The control motor of the grinding device drives and adjusts the rotation angle of the adjusting wheels, and through the eccentric through-hole of the adjusting wheels, adjusts and defines the lateral position of the upper part of the sleeve, thereby controlling the lateral position of the grinding head reference point. The lower end of the housing is connected to the sleeve on which the grinding motor is mounted via a rubber spring.

[0047] As can be seen, the sleeve and grinding motor, which are installed as a single unit, are connected to the housing, cover, adjusting wheel, and support wheel, which are installed together, via the rubber spring. During the grinding process, the housing of the outer shell uses the rubber spring to counteract the feed reaction force, cutting torque, and the lateral movement and torsion of the grinding head caused by vibration. The housing of the outer shell restricts the six degrees of freedom of the grinding head reference point through the rubber spring, enabling force-controlled omnidirectional floating grinding. Therefore, compared with existing multi-dimensional force-controlled floating grinding technology, the grinding device of the present invention, by restricting the six degrees of freedom of the grinding head reference point through the rubber spring, can achieve force-controlled omnidirectional floating grinding. The grinding device of the present invention does not require precision parts such as spherical bearings, has a simple structure, and is low in cost.

[0048] Furthermore, the rubber spring of this invention contains a cylindrical spiral steel wire inside, and rubber is wrapped around the steel wire, hence it is also called a composite spring. Therefore, compared with existing floating tool holders that use metal springs, the grinding device of this invention can simultaneously withstand multi-directional loads and achieve omnidirectional floating; it can absorb vibration energy and avoid noise generation, thus having good shock absorption, vibration reduction, and noise reduction effects; it has strong load-bearing capacity, stable operation, and long service life.

[0049] (2) The control motor of the grinding device of the present invention is connected to the axle of the support wheel, which serves as the driving wheel, to drive the support wheel and drive and adjust the rotation angle of the adjusting wheel; and through the eccentric through hole of the adjusting wheel, it adjusts and limits the lateral position of the upper part of the sleeve, thereby controlling the lateral position of the grinding head reference point. Therefore, the grinding device of the present invention can achieve force-controlled omnidirectional floating grinding simply by adjusting the rotation angle of the control motor; and it can control the multi-dimensional movement of the grinding head reference point by utilizing the one-dimensional rotational motion of the control motor. Compared with existing force control devices that utilize hydraulic, electromagnetic, and pneumatic principles, the grinding device of the present invention has strong control capability, simple control principle, fewer control links, and fewer parts, thus resulting in a simple structure and low cost.

[0050] Furthermore, the rubber spring of the present invention has a longitudinal cylindrical structure; relative to the longitudinal direction, the grinding device has a small lateral floating range and insufficient passive force control in the lateral direction. The grinding device of the present invention utilizes the rotational motion of the control motor to adjust and limit the lateral position of the upper part of the sleeve, achieving active force control in the lateral direction and improving control accuracy; it can compensate for the shortcomings of the rubber spring having a small lateral floating range and insufficient passive force control in the lateral direction.

[0051] (3) The rubber spring passes through the sleeve via its inner hole and abuts against the lower surface of the adjusting wheel at its upper end. Preferably, its lip engages with the gap between the sleeve and the eccentric through hole of the adjusting wheel to ensure a uniform gap fit. The grinding device of the present invention uses the control motor to regulate the lateral position of the upper part of the sleeve, and simultaneously regulates the lateral position of the upper end of the rubber spring. The grinding device of the present invention achieves active force control in the lateral direction and uses the rubber spring to achieve omnidirectional floating grinding. Therefore, the grinding device of the present invention combines active force control and passive force control using the rubber spring, solving the technical contradiction of "active force control is complex, with high precision and cost; passive force control is simple, with low precision and cost".

[0052] Furthermore, the adjusting wheel of the present invention controls the lateral position of the upper end of the rubber spring, adjusting only the lateral position of the upper part of the sleeve, without limiting the position of the upper end of the sleeve, and without affecting the longitudinal movement of the sleeve. Therefore, the grinding device of the present invention utilizes the rubber spring to combine active force control and passive force control, resulting in a large adjustment and floating range.

[0053] (4) The control method of the present invention preferably establishes a calculation model before leaving the factory, stores the rotation angle of the control motor when the reference point of the grinding head reaches different positions; writes a processing program and conducts grinding processing experiments. The control method uses processing experiments to select the rubber spring and optimize the rotation angle of the control motor when the grinding head reaches different positions; the selected rubber spring can generate the optimal elastic force and preload to adapt to the different types of workpiece blanks that customers need to grind; the optimized control motor can actively adjust the cutting force in the lateral direction and improve the control accuracy; it makes up for the shortcomings of the rubber spring having a small lateral floating amount and insufficient lateral passive force control.

[0054] Therefore, compared with existing multi-dimensional force control technology, the control method of the present invention utilizes processing experiments to adapt to different types of workpiece blanks that require grinding and processing according to customer needs. It also optimizes the rotation angle of the control motor when the grinding head reaches different positions, improves control accuracy, and meets the grinding effect and processing efficiency requirements of different structural features of the workpiece blanks. During grinding, the rotation angle of the control motor stored in the calculation model is called only according to the position of the grinding head. Without using sensors for active force control, it can realize the combination of active force control and passive force control, solving the technical contradiction of "active force control is complex, with high accuracy and cost; passive force control is simple, with low accuracy and cost".

[0055] (5) The control method of the present invention achieves force-controlled omnidirectional floating grinding by optimizing the rotation angle of the control motor when the grinding head reaches different positions through processing experiments, thereby adapting to the tolerance and surface quality changes of the workpiece blank at the processing location. Compared with existing multi-dimensional force control technology, the control method no longer uses sensors to regulate the movement path and processing parameters of the grinding head during the grinding process, and does not adopt closed-loop control, which greatly reduces the difficulty and cost of active force control and improves control accuracy.

[0056] Furthermore, the control method of the present invention adopts open-loop control and is integrated into the robot's control system, which can reduce development difficulty. The control method establishes a computational model through processing experiments, simplifies the control process during processing, opens up a new channel for intelligent control in the field of force-controlled grinding technology, and can promote the intelligent development of grinding robots, as well as promote the application and development of new-generation information technology.

[0057] (6) The types of workpiece blanks used by certain manufacturing enterprises are limited, and the grinding robots employed are generally designed for specific scenarios. Therefore, the grinding device of this invention establishes and stores a computational model and writes and stores a processing program for different types of workpiece blanks for customers, and conducts grinding processing experiments; it adopts customized production for specific customers, which can improve control accuracy, enhance grinding effect, improve processing efficiency, and increase customer satisfaction. This invention discovers and fully utilizes the characteristic that the types of workpiece blanks that need to be ground by certain manufacturing enterprises are limited, which can reduce production and operation risks and increase economic and social benefits. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the overall structure of the polishing device; Figure 2 for Figure 1 A magnified view of the area within the dashed circle. Figure 3 For the rubber spring 2 in Figure 1 A bottom view of the location; Figure 4 For the housing 11 in Figure 1 Top view of the location; Figure 5 This is a schematic diagram illustrating the cooperation principle between the adjusting wheel 13 and the support wheel 14.

[0059] Explanation of reference numerals in the attached drawings: 1. Outer shell; 11. Housing; 12. Protective cover; 121. Ring groove; 13. Adjusting wheel; 131. Sealing ring; 132. Eccentric through hole; 14. Support wheel; 15. Groove; 16. Shaft hole; 17. Closure hole; 18. Fastening hole; 19. Mounting sleeve; 2. Rubber spring; 21. Steel wire; 22. Chamfered surface; 23. Axial groove; 3. Sleeve; 31. Rubber ring; 32. Lower thread; 4. Grinding motor; 41. Main spindle; 42. Mounting seat; 5. Control motor; 6. End cover; 61. Raised rib; 62. Screw; 63. Screw hole; 64. Internal thread; 7. Bushing; 71. External thread; 72. Tapered hole; 8. Protective sleeve; 81. Clamp. Detailed Implementation

[0060] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments: The orientations described in this specification are based on the working position of the grinding device; the vertical direction is the longitudinal direction, and the direction perpendicular to the longitudinal direction is the transverse direction; other directions follow the same pattern. Figure 1 In the middle, the vertical direction is the vertical direction, and other directions follow the same pattern. Figure 1 This is a schematic diagram of the overall structure of the grinding device, including a housing 1, a rubber spring 2, a sleeve 3, a grinding motor 4, a control motor 5, an end cap 6, a bushing 7, and a protective sleeve 8; the grinding head is a general standard part and is not included in the design. Figure 1 Draw in the middle; Figure 2 for Figure 1 A magnified view of the area within the dashed circle.

[0061] The housing 11 is an upright cylindrical structure, tapering inward at the bottom and including a surrounding groove 15 on the lower part of its outer surface; the housing 11 forms a constriction 17 at the lower end and a flat flange at the upper end; the housing 11 and its above-mentioned structural features are preferably made of aluminum alloy and formed by die casting. The longitudinal shaft hole 16 and fastening hole 18 included in the flange of the housing 11 are preferably machined.

[0062] The cover 12 is an oblong cover with a downward bend at the outer edge to form a lower edge. It includes a longitudinally penetrating central hole, and the lower surface of the central hole edge includes an annular groove 121. The cover 12 and its above-mentioned structural features are preferably formed from aluminum alloy sheet by forging. The cover 12 includes a through hole at a lateral position corresponding to the fastening hole 18 of the housing 11, and a shaft hole at a lateral position corresponding to the shaft hole 16 of the housing 11. Both the through hole and the shaft hole of the cover 12 are preferably machined.

[0063] The adjusting wheel 13 is a disc-shaped gear with teeth on its outer circumference and a circular eccentric through hole 132. The eccentric through hole 132 preferably has a flared lower end with an increased diameter. The adjusting wheel 13, its teeth, the eccentric through hole 132, and the flared lower end of the eccentric through hole 132 are preferably formed from aluminum alloy sheet by machining. A circular sealing ring 131 is fixedly installed on the outer surface of the upper surface of the adjusting wheel 13. The sealing ring 131 has a circular structure, is elastic, and is preferably a commercially available sealing ring. The sealing ring 131 is preferably fixedly installed on the outer surface of the upper surface of the adjusting wheel 13 using existing resin adhesive.

[0064] The support wheel 14 is a disc-shaped gear, containing a longitudinal axle at its center and teeth on its outer circumference. The support wheel 14 and its structural features are manufactured using existing gear materials and processes, preferably engineering plastics, aluminum alloys, or stainless steel. The mounting cylinder 19 is a transverse cylinder, securely connected to the outer surface of the housing 11 at its right end, forming a single unit, and includes a flange at its left end. Preferably, it is made of the same material as the housing 11 and integrally die-cast. The through-hole in the flange of the mounting cylinder 19 is preferably machined.

[0065] Figure 3 For the rubber spring 2 in Figure 1 The bottom view shows the structural features of its lower end face. The dashed lines in the figure represent the cylindrical spiral steel wire 21 contained inside. The rubber spring 2 has a longitudinal straight cylindrical structure with a circular inner hole to withstand compression. Preferably, the rubber spring 2 has an upward protrusion at the upper end of the inner hole to form a lip. The rubber spring 2 contains a cylindrical spiral steel wire 21 inside, and rubber is wrapped around the steel wire 21. The rubber spring 2 has uniformly distributed chamfered planes 22 on its outer surface, presenting a non-circular cross-section. It has an axial groove 23 on its lower end face. The rubber spring 2 and its above-mentioned structural features are preferably formed using existing composite spring materials and processes, or can be achieved by selecting existing composite spring products.

[0066] like Figure 1 and Figure 2 As shown, the sleeve 3 is a longitudinal cylindrical structure with an inner hole and a flange formed at the upper end, preferably formed from an aluminum alloy tube by forging. The lower thread 32 included at the lower end of the outer surface of the sleeve 3 is preferably formed by machining. The rubber ring 31 is an annular structure with elasticity, preferably made from existing rubber ring products; the fixed installation of the rubber ring 31 on the lower surface of the flange of the sleeve 3 is preferably achieved by existing resin adhesive bonding.

[0067] like Figure 1As shown, the grinding motor 4 includes a spindle 41 and a mounting base 42, preferably implemented using existing motor products. The external thread at the lower end of the spindle 41 is preferably machined. The control motor 5 includes an upward-facing spindle that drives the support wheel 14 and adjusts the rotation angle of the adjusting wheel 13, preferably implemented using existing servo motor products. The spindle of the control motor 5 is connected to the axle of the support wheel 14, which serves as the drive wheel; preferably, the spindle of the control motor 5 is directly connected to the support wheel 14 as its axle; and preferably, a mechanical connection is used for ease of disassembly and maintenance. The control motor 5 is mounted on the lower surface of the flange of the housing 11, preferably using known fasteners for ease of disassembly and maintenance.

[0068] like Figure 1 and Figure 2 As shown, the end cap 6 is an upward-facing circular cap structure with an outer upper edge and radial ribs 61 on its upper surface. The ribs 61 are radial straight strips that connect to the outer upper edge of the end cap 6 at their outer ends. The end cap 6 has a through hole at its center and an inner lower edge at the edge of the through hole. The end cap 6 and its above-mentioned structural features are preferably made of aluminum alloy and formed by die casting. The transverse screw hole 63 and its internal thread, as well as the internal thread 64 on the inner surface of the through hole, are preferably machined. The screw hole 63 is fitted with a screw 62 using its internal thread; the screw 62 is preferably implemented using existing standard set screw parts.

[0069] like Figure 1 As shown, the bushing 7 is a longitudinal cylindrical structure with an inner hole at its center, an internal thread at the upper end of the inner hole, an external thread 71 at the lower end of its outer surface, and a tapered hole 72 at the lower end of the inner hole. Preferably, it is made of aluminum alloy tubing formed by machining. A spring clip is mounted on the bushing 7 via the tapered hole 72, a nut is mounted via the external thread 71, and the spring clip clamps the shank of the grinding head, allowing the grinding head to be mounted on the lower end of the bushing 7.

[0070] The spring collet adopts a conical cylindrical structure with a conical outer surface and an axial inner hole. It has radial grooves on its wall, allowing for elastic inward and outward expansion. The conical outer surface engages with the conical hole 72 of the bushing 7, and the inner hole is used to insert and clamp the shank of the grinding head. This is preferably achieved using existing spring collet products. The nut includes a threaded hole with internal threads on its inner surface. These internal threads engage with the external threads 71 ​​of the bushing 7, driving the spring collet to move axially and elastically retract, thus clamping and fixing the shank of the grinding head. The nut is preferably achieved using existing tool holder nuts or collet nuts. The grinding head includes a head and a shank. The head has hard abrasive or cutting teeth on its surface. The shank is a straight rod structure used for clamping and is also called a tool holder. The grinding head is preferably achieved using known grinding head or file products, depending on the material of the workpiece blank to be ground and the structural characteristics of the processing area.

[0071] like Figure 1 As shown, the sheath 8 has a longitudinal conical structure, with a circular upper opening at the top and a circular lower opening at the bottom. It also has a flange at the top and a corrugated outer surface, allowing for longitudinal elastic expansion and contraction. Preferably, this is achieved using existing corrugated elastic rubber sleeves. A clamp 81 is installed below the flange on the sheath 8; the clamp 81 is preferably a readily available stainless steel clamp for ease of fastening, installation, disassembly, and maintenance.

[0072] Figure 4 For the housing 11 in Figure 1 The top view shows the structural feature of the flat flange formed by the outward protrusion of the upper end of the housing 11. The oblong cover 12 abuts against the upper surface of the outer edge of the flange of the housing 11 via its lower edge, thus achieving a secure installation of the cover 12 on the housing 11. Therefore, the flange of the housing 11 is oblong. Figure 4 In the described embodiment, the outer upper surface of the flange of the housing 11 is preferably ground to facilitate mating with the lower edge of the cover 12. Figure 4 In the described embodiment, four holes are included around the shaft hole 16 for fasteners to pass through, enabling the control motor 5 to be mounted on the lower surface of the flange of the housing 11. Furthermore, the cover 12 and the flange of the housing 11 are preferably further modified and optimized in shape to facilitate weight reduction.

[0073] exist Figure 4In the illustrated embodiment, the cross-sectional shape of the constriction 17 is a closed shape formed by the intersection of concentric equilateral triangles and circles, comprising three arcs and three line segments evenly distributed along the circumference. The constriction 17 passes through the lower part of the rubber spring 2 and engages with the lower part of the outer surface of the rubber spring 2 to prevent relative rotation. Therefore, the presence of chamfered surfaces 22 evenly distributed along the circumference on the outer surface of the rubber spring 2 is merely a preferred embodiment. The constriction 17 and the rubber spring 2 may also employ other structural features that allow them to engage with each other and prevent relative rotation.

[0074] Figure 5 This is a schematic diagram illustrating the cooperation principle between the adjusting wheel 13 and the support wheel 14, showing the relative lateral positions of the adjusting wheel 13, the support wheel 14, and the flange of the housing 11. Figure 5 The structural features of the flange of the housing 11 are represented by a double-dotted line. The inner wall of the cylinder of the housing 11 extends upward to form the circular inner edge of the flange. The flange of the housing 11 is offset to the right relative to the cylinder of the housing 11, being wider on the right and narrower on the left, to facilitate the installation of the control motor 5 on the lower surface of the right side and avoid interference. The diameter of the adjusting wheel 13 is larger than the inner diameter of the cylinder of the housing 11, that is, larger than the inner diameter of the flange of the housing 11, to achieve longitudinal limiting of the adjusting wheel 13 and prevent the adjusting wheel 13 from falling into the cylinder of the housing 11. The adjusting wheel 13 is offset to the right relative to the circular inner edge of the flange of the housing 11, and the eccentric through hole 132 of the adjusting wheel 13 is also eccentric relative to the adjusting wheel 13; this increases the eccentricity of the eccentric through hole 132 relative to the inner edge of the flange of the housing 11, that is, increases the eccentricity relative to the inner wall of the cylinder of the housing 11, thereby increasing the lateral adjustment range of the grinding device. When designing and implementing the system, the wall thickness of the rubber spring 2 should be taken into account to avoid interference.

[0075] Preferably, the control method involves establishing and storing a computational model in the robot's control system before the robot leaves the factory. The grinding device is manufactured to order, with the model number of the workpiece blank requiring grinding recorded as follows: m Existing grinding robots include a body, upper arm, lower arm, robotic arm, and control system. The control system stores a control program; preferably, the control program performs point-to-point control based on the grinding head position, forming a processing program that includes a processing path and related processing parameters; the processing path is preferably expressed based on the reference point position of the grinding head, and at least includes a coordinate sequence of the movement of the grinding head reference point during processing. i , m , x , y , zThe reference point of the grinding head is preferably located near the rotation center of the cutting position. During the machining process, based on the tool compensation method of existing CNC programs, the cutting position, i.e., the contact position between the grinding head and the workpiece blank, is calculated according to the structural characteristics of the workpiece blank at the machining location. The relevant machining parameters include at least the cutting force, cutting speed, and feed rate, which are technical parameters related to cutting machining and adopt existing machining technologies, and will not be discussed in detail here.

[0076] The control method records the rotation angle of the control motor 5 as... θ ; θ Preferably, the line connecting the main shaft axis of the control motor 5 and the axis of the adjusting wheel 13 in the transverse plane is used as a reference, i.e., 0°; for example... Figure 4 As shown, the cylindrical axis of the housing 11, the axis of the mounting cylinder 19, the axis of the adjusting wheel 13, and the axis of the main shaft of the control motor 5 are preferably in the same longitudinal plane.

[0077] In the grinding experiment, the control method described herein uses a force sensor mounted on the mounting sleeve 19 of the outer shell 1, which is then mounted on the robot's manipulator. The force sensor is preferably a known six-dimensional force sensor. The cutting force obtained by the force sensor... f ( i , m , x , y , z The sensor value with the largest numerical change obtained in the grinding process experiment is preferred. The grinding head reference point reaches the [number missing]. i The coordinates are ( x , y , z When the position of the workpiece blank is determined, the dimension in which the sensor values ​​change the most due to the structural characteristics of the workpiece blank is the most sensitive to changes in the cutting force value. Alternatively, mathematical methods can be used to comprehensively calculate the sensor values ​​changing in multiple dimensions. During grinding, due to the removal of the force sensor, changes in the robot's structural dimensions, and changes in the workpiece blank clamping position, the machining route needs to be adjusted. This is achieved based on existing programming and machining technologies and will not be detailed further. After adjustments and changes, a trial cut of the first piece is preferred to ensure safety.

[0078] The control method is applied to the numbered... m When conducting multiple grinding experiments on a workpiece blank, it is necessary to perform multiple grinding experiments on the same workpiece blank, and also on the same workpiece blank with the same number. m Multiple grinding experiments were conducted on different workpiece blanks. To improve control accuracy, enhance grinding effect, and increase processing efficiency, rubber spring 2 was selected and optimized through multiple grinding experiments. θ (i , m , x , y , z When developing a system, it is preferable to write intelligent control programs for human-machine collaborative operation; and it is also preferable to utilize artificial intelligence, big data and other new-generation information technologies to extract and accumulate relevant knowledge.

[0079] The control method described in this invention allows for the customized production of the grinding device based on the specific workpiece blank model required for grinding by the customer. Specific manufacturing enterprises typically have a limited range of workpiece blank types, meaning a single enterprise grinds only a few different models. A single grinding robot is used to grind only one or a few workpiece blank models; therefore, the workload for adjusting the processing program and grinding device is minimal. The grinding device adjustment is preferably performed by replacing the rubber spring 2 on-machine, eliminating the need to replace the entire grinding device, which is simple and convenient. When replacing the rubber spring 2, only the protective sleeve 8, end cap 6, and grinding head need to be removed on-machine for replacement. This simplicity and convenience avoids the need to disassemble the entire grinding device from the robot's robotic arm, facilitating automated operation and promoting the application and development of service robots.

[0080] The control method described above allocates storage space in the storage medium of the robot control system, establishes and stores the computational model, and writes and stores the processing program. All of these are based on existing industrial robot development technologies and implemented using existing programming software. The start-stop control of the grinding motor 4 and the rotation angle adjustment of the control motor 5 are also based on existing industrial robot development technologies and will not be discussed in detail here.

[0081] The above embodiments are merely preferred embodiments of the present invention and do not constitute a limitation thereof. Changes in materials and manufacturing processes, provided they meet the structural and performance requirements of the present invention, are all within the scope of protection of the present invention.

Claims

1. A force-controlled omnidirectional floating grinding device for robots, comprising a grinding head, characterized in that: It includes a housing (1), a rubber spring (2), a sleeve (3), a grinding motor (4), a control motor (5), an end cap (6), and a bushing (7). The housing (1) is installed on the robot's manipulator, the grinding head is installed on the bushing (7), and the rubber spring (2) and the control motor (5) are used for universal floating force control to realize force-controlled universal floating grinding of the workpiece blank. The outer shell (1) comprises a cylindrical shell (11) perpendicular to each other and a mounting cylinder (19), which is mounted to the robot's manipulator. The outer casing (1) has an adjusting wheel (13) and a support wheel (14) installed on the housing (11). The upper end of the rubber spring (2) is pressed by the adjusting wheel (13), and the support wheel (14) engages with the adjusting wheel (13) to support the adjusting wheel (13) and adjust its rotation angle, so as to adjust and limit the lateral position of the upper end of the rubber spring (2) and the upper part of the sleeve (3). The adjusting wheel (13) includes a circular eccentric through hole (132), and the sleeve (3) passes through the eccentric through hole (132) at the top. The adjusting wheel (13) is able to rotate relative to the sleeve (3), so that the adjusting wheel (13) can adjust and limit the lateral position of the upper part of the sleeve (3). The housing (11) is a vertical cylindrical structure with a constriction (17) at the lower end, allowing the rubber spring (2) to pass through the constriction (17) and extend and retract freely. The constriction (17) is a longitudinal non-circular through hole that mates with the lower part of the outer surface of the rubber spring (2) to limit the lateral position of the rubber spring (2) and the sleeve (3) at the lower part and to prevent the rubber spring (2) from rotating relative to the housing (11). The rubber spring (2) is a longitudinal cylindrical structure with an inner hole through which the sleeve (3) passes; the rubber spring (2) abuts against the adjusting wheel (13) at the upper end and against the end cap (6) at the lower end, and bears the compression action; The sleeve (3) is a longitudinal cylindrical structure containing an inner hole through which the bushing (7) passes. The grinding motor (4) is installed on the upper end of the sleeve (3); the grinding motor (4) includes a main shaft (41), which is fastened to the bushing (7) to drive the grinding head to perform force-controlled universal floating grinding; The control motor (5) is installed on the housing (11); the control motor (5) is connected to the support wheel (14), drives the support wheel (14), and drives and adjusts the rotation angle of the adjustment wheel (13); The end cap (6) is an upward-facing round cap structure with a through hole in the center. It is installed at the lower end of the sleeve (3) using the through hole to prevent the end cap (6) from rotating relative to the sleeve (3).

2. A force-controlled omnidirectional floating grinding device for a robot according to claim 1, characterized in that: The rubber spring (2) has an axial groove (23) on its lower end face; The end cap (6) has radial ribs (61) on its upper surface. The ribs (61) are used to engage with the axial groove (23) at the lower end of the rubber spring (2) to prevent the rubber spring (2) from rotating relative to the end cap (6). The end cap (6) forms an inner lower edge at the edge of the through hole, and includes a transverse screw hole (63) on the inner lower edge. The screw hole (63) contains an internal thread, and a screw (62) is installed using the internal thread, so that the screw (62) abuts against the sleeve (3) and has a tightening effect, preventing the end cap (6) from rotating relative to the sleeve (3).

3. A force-controlled omnidirectional floating grinding device for a robot according to claim 1, characterized in that: The outer casing (1) has a cover (12) installed on the casing (11); The housing (11) has a flange protruding outward at the upper end. The flange includes a longitudinal shaft hole (16) and a fastening hole (18). The support wheel (14) is installed through the shaft hole (16), and the fastening hole (18) is used to pass through the fastener, so that the cover (12) is fastened to the housing (11). The cover (12) has a through hole in a lateral position corresponding to the fastening hole (18) of the housing (11), through which a fastener passes to achieve the fastening installation of the cover (12) on the housing (11).

4. A force-controlled omnidirectional floating grinding device for a robot according to claim 3, characterized in that: The cover (12) includes a longitudinal through hole in the middle, through which the sleeve (3) passes to avoid interference; The central hole of the cover (12) is circular and coaxial with and parallel to the adjusting wheel (13); The cover (12) has an annular groove (121) on the lower surface of the edge of the hole therein, and the annular groove (121) is used to achieve dynamic sealing relative to the adjusting wheel (13); The cover (12) includes a shaft hole at a lateral position corresponding to the shaft hole (16) of the housing (11), through which a support wheel (14) is mounted; thereby enabling the support wheel (14) to be supported and to rotate relative to it.

5. A force-controlled omnidirectional floating grinding device for a robot according to claim 1, characterized in that: There are at least three support wheels (14) to define the lateral position of the adjusting wheel (13), one of which serves as the driving wheel; The support wheel (14), which serves as the driving wheel, is connected to the control motor (5) to obtain driving torque, drive and adjust the rotation angle of the adjustment wheel (13) to adjust and limit the lateral position of the upper part of the sleeve (3).

6. A force-controlled omnidirectional floating grinding device for a robot according to claim 4, characterized in that: The adjusting wheel (13) is a disc-shaped gear, and a circular sealing ring (131) is fixedly installed on the outside of its upper surface. The sealing ring (131) is a circular ring structure, coaxial with the adjusting wheel (13), and has elasticity. It is inserted into the annular groove (121) of the cover (12), so that the adjusting wheel (13) abuts against the cover (12) through the sealing ring (131) to achieve dynamic sealing and prevent the intrusion of chips and dust.

7. A force-controlled omnidirectional floating grinding device for a robot according to claim 1, characterized in that: The rubber spring (2) has a non-circular cross-section; The rubber spring (2) engages with the constriction (17) at the lower end of the housing (11) on the lower part of the outer surface, so that the rubber spring (2) can freely extend and retract through the constriction (17) to limit the lateral position of the rubber spring (2) and the sleeve (3) at the lower part and prevent the rubber spring (2) from rotating relative to the housing (11).

8. A force-controlled omnidirectional floating grinding device for a robot according to claim 1, characterized in that: The sleeve (3) has a flange at its upper end; The flange of the sleeve (3) includes a longitudinal through hole, through which fasteners pass and are fastened to the grinding motor (4), so that the grinding motor (4) is mounted on the upper end of the sleeve (3). The sleeve (3) has a rubber ring (31) fixedly installed on the lower surface of its flange, and the rubber ring (31) contacts the upper surface of the adjusting wheel (13); The rubber ring (31) has a circular structure, is elastic, and can provide a cushioning effect.

9. A force-controlled omnidirectional floating grinding device for a robot according to claim 1, characterized in that: It includes a sheath (8); The housing (11) is recessed at the bottom and includes a surrounding groove (15) on the lower part of the outer surface. The sheath (8) is a longitudinal conical structure, with a circular upper opening at the top and a circular lower opening at the bottom. The sheath (8) is inserted into the shell (11) of the outer shell (1) through its upper opening. The upper end of the sheath (8) is inserted into the groove (15) of the housing (11), so that the sheath (8) is installed on the housing (11) of the outer shell (1) at the upper end. The sheath (8) is recessed at the lower end, and the inner lower edge of the end cap (6) extends out of its lower opening; The sheath (8) has a corrugated outer surface and can stretch and contract elastically in the longitudinal direction, so that the sheath (8) is attached to the lower surface of the end cap (6) at the lower end, preventing chips and dust from entering and providing protection.

10. A smart omnidirectional floating control method for a robot equipped with the grinding device described in any one of claims 1-9, for performing omnidirectional floating force-controlled grinding, characterized in that: Establish and store the following computational model: First, number the workpiece blank model and record it as follows: m The coordinates of the grinding head reference point are marked as ( x, y, z The rotation angle of the control motor (5) is denoted as . θ ; The grinding device uses the mounting sleeve (19) of the outer shell (1) to mount a force sensor, which is then mounted on the robot's manipulator. The cutting force obtained by the force sensor is recorded as... f ; Record and store θ ( i , m , x , y , z )and f ( i, m, x, y, z ); in, i Coordinate sequence number; θ ( i, m, x, y, z The grinding process number is... m During the workpiece blanking process, the reference point of the grinding head reaches the first... i The coordinates are ( x, y, z When the position is ), the rotation angle of the control motor (5); f ( i, m, x, y, z The grinding process number is m During the workpiece blanking process, the reference point of the grinding head reaches the first... i The coordinates are ( x, y, z The cutting force value obtained by the force sensor at the position of ). Second, regarding the number m Write a machining program for the workpiece blank, which should at least include the coordinate sequence of the movement of the grinding head reference point during the machining process. i, m, x, y, z }; Third, regarding the number m A grinding experiment was conducted on the workpiece blank to observe and record the grinding effect. f ( i, m, x, y, z The maximum and minimum values ​​of the cutting force are obtained and denoted as follows: maxf ( m )and minf ( m ); Fourth, continue the polishing and processing experiments, and make adjustments. θ ( i, m, x, y, z Replace the rubber spring (2) to reduce ( maxf ( m ) – minf ( m The value of )) improves control precision; The control method includes the following steps: Step 1, settings i The initial value is 0; set the variable tempx, tempy and tempz And let their initial values ​​be { 0, m, x, y, z }middle x, y, and z The value of ; adjust the rotation angle of the control motor (5) to 0°; The second step involves the robot targeting the numbered... m The workpiece blank is then subjected to grinding and processing operations; the grinding motor (4) is started. The third step involves moving the reference point of the grinding head, whose coordinates are { x, y, z } changes; Determine if the grinding head reference point has reached the first... i There are coordinate points; if ( tempx==x and tempy==y and tempz= =z If the condition is true, then the destination has been reached; otherwise, the destination has not been reached. Fourth step, if reached, then: {Adjust the rotation angle of the control motor (5) to θ ( i, m, x, y, z To ensure the required polishing effect and processing efficiency; i = i + 1 ； variables tempx , tempy and tempz The values ​​are set to { i, m, x, y, z }middle x, y, and z The value; Proceed to step three; Fifth step: Determine if processing is complete; if not, proceed to third step. The grinding motor (4) stops; Finish.

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