A method for setting a load balancing device for a heavy-load robot

Abstract

A method for setting a balanced load device for a heavy-load robot, the steps of which include: setting up the heavy-load robot; obtaining the total load m borne by the three-axis forearm; setting up a balanced load device, obtaining a balanced load m1, and making the torque generated by the balanced load m1 opposite to the torque generated by the total load m; in the initial state, obtaining the total center of gravity O' and the distance L, and measuring the total load angle α; obtaining the balanced center of gravity O" and the distance L1, and measuring the balanced angle β; starting from the initial state, rotating the heavy-load robot by an angle X, and obtaining the peak value of the motor torque N3 at different balanced angles β, then comparing the peak value of the motor torque N3 at different balanced angles β, selecting the balanced angle β corresponding to the minimum peak value of the motor torque N3, and balancing the position of the center of gravity O" accordingly. Compared with the prior art, the method for setting a balanced load device for a heavy-load robot of the present invention can reduce the motor torque and achieve lightweighting of the robot.

Description

Technical Field

[0001] The present invention relates to the field of robot technology, and in particular to a method for setting a load balancing device of a heavy-load robot. Background Art

[0002] In today's society, robots are gradually replacing humans in some tasks that are highly repetitive, labor-intensive, and require harsh working environments, due to their high load capacity and high efficiency. Heavy-load robots that carry goods are one of them. Figure 1 The patent with publication number CN216657936U discloses a six-axis palletizing robot, including a gripper mechanism 1, and a base 2, a first joint 3, a first connecting rod 4, a second joint 5, a second connecting rod 6, and a third joint 7 connected in sequence. The gripper mechanism 1 is located at the end of the third joint 7. The first joint 3, the first connecting rod 4, the second joint 5, the second connecting rod 6, and the third joint 7 rotate relatively on the base 2, thereby driving the gripper mechanism 1 to move to the cargo for grabbing; after grabbing, the first joint 3, the first connecting rod 4, the second joint 5, the second connecting rod 6, and the third joint 7 continue to rotate relatively, driving the gripper mechanism 1 together with the cargo to be transferred to the cargo storage point for palletizing.

[0003] It can be seen from the above that in the prior art, when the heavy-load robot is carrying goods, the second joint rotation axis is parallel to the horizontal plane, and is mainly responsible for driving the goods to swing in a vertical plane perpendicular to the horizontal plane. The rotation center is relatively far from the goods, and the second joint bears most of the torque generated by the goods, resulting in the motor driving the second joint to rotate requiring a larger output torque. In order to ensure sufficient load capacity, a large torque, direct-connected motor and reducer are generally used to drive the second joint to rotate. However, as the required load capacity increases, the volume and weight of the motor and reducer increase accordingly, and the weight borne above the first joint also increases accordingly, and the volume and weight of the motor and reducer driving the first joint also increase accordingly, which ultimately leads to a bulky structure of the robot and low flexibility, which does not meet the requirements of lightweight, and seriously affects the improvement of the robot's movement speed. In addition, in addition to bearing the weight of the goods during work, the heavy-load robot also needs to bear its own weight, and the joints rotate relative to each other during the handling process, so the center of gravity position changes continuously. Among all the joints, the second joint swings greatly, so the center of gravity of the total load driven by it changes the most. The change of the center of gravity of the total load of the second joint often causes the robot to be unstable, shake, or even flip over, causing safety accidents. This situation is particularly serious for six-axis robots with a long distance between the cargo and the base and a large force arm, which affects the safety of the robot. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a method for setting a load balancing device for a heavy-load robot, which can reasonably reduce the motor torque required to drive the joint movement by setting a load balancing device for the robot.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for setting a load balancing device of a heavy-load robot comprises the following steps:

[0007] A heavy-load robot is provided, comprising a one-axis joint located on a horizontal plane, a three-axis forearm located above the one-axis swivel seat, and a three-axis motor installed on the one-axis joint; the three-axis forearm rotates around a first axis parallel to the horizontal plane; the output axis of the three-axis motor is a second axis; the first axis is parallel to the second axis;

[0008] Obtain the total load m borne by the three-axis forearm;

[0009] A load balancing device is provided, including a first adapter plate, a pull rod and a load balancing block; so that under the drive of the three-axis motor, the first adapter plate drives the three-axis forearm to rotate around the first axis through the pull rod;

[0010] Obtaining a balancing load m1, including the weight of the first adapter plate and the balancing load block; the moment generated by the balancing load m1 relative to the second axis is opposite in direction to the moment generated by the total load m relative to the first axis;

[0011] Setting the heavy-load robot to an initial state;

[0012] Projecting along the first axis, in the initial state, obtain the position of the total center of gravity O' of the total load m and the distance L between the total center of gravity O' and the first axis formed by the first axis, and measure the total load angle α of the line between the center of gravity O' of the total load m and the first axis relative to the horizontal plane;

[0013] Projecting along the first axis, in the initial state, obtain the position of the balancing center of gravity O" of the balancing load m1 and the distance L1 between the balancing center of gravity O" and the second axis formed by the second axis, and measure the balancing angle β of the line connecting the balancing center of gravity O" and the second axis relative to the horizontal plane;

[0014] Starting from the initial state, the three-axis forearm is rotated around the first rotation axis, and the angle of rotation is the rotation angle X. The peak value of the motor torque N3 at different balance angles β is obtained according to the following formula:

[0015] N3==|(|mg*cos(α-X)*L|-|m1g*cos(β+X)*L1|)| / T, where T is the reduction ratio between the three-axis motor and the reducer connected thereto;

[0016] The peak values ​​of the motor torque N3 at different balancing angles β are compared, the balancing angle β corresponding to the minimum peak value of the motor torque N3 is selected, and the position of the balancing center of gravity O" is adjusted according to the selected balancing angle β.

[0017] Compared with the prior art, the method for setting a balanced load device for a heavy-load robot of the present invention provides a balanced load device on the heavy-load robot so that the torque generated by the balanced load device offsets the torque of the total load, thereby reducing the torque required to drive the joint to rotate the motor. Moreover, by reasonably setting the position of the balanced load block and adjusting the position of its center of gravity, the peak value of the torque required by the motor can be further reduced, thereby effectively controlling the maximum value of the required motor torque in the dynamic process of carrying heavy loads, and ultimately reducing the volume and weight of the motor and the reducer, thereby achieving lightweighting of the robot.

[0018] Furthermore, setting up the balancing load device also includes setting up a second adapter plate hinged to the one-axis joint, and the axis of the hinge axis between the one-axis joint and the second adapter plate is parallel to the first axis; the balancing load block is installed between the first adapter plate and the second adapter plate, and the second adapter plate supports the balancing load block.

[0019] Further, an angle value β1 is selected as the balance angle β, and the rotation angle X varies between a first limit swing angle θ and a second limit swing angle ω; a coordinate diagram is established with the three-axis motor torque N3 as the ordinate and the rotation angle X as the abscissa, and an N3-X relationship curve is calculated and obtained according to the formula when the balance angle β=β1 and the rotation angle X vary between the first limit swing angle θ and the second limit swing angle ω, and the peak value of the three-axis motor torque N3 when the balance angle β=β1 is obtained from the N3-X relationship curve; the balance angle β is set to different angle values, and different N3-X relationship curves corresponding to different balance angles β when the rotation angle X is at the first limit swing angle θ and the second limit swing angle ω are obtained, and the peak values ​​of the three-axis motor torque N3 in the different N3-X relationship curves corresponding to each different balance angle β are obtained, and each N3-X relationship curve is directly compared in an intuitive manner to intuitively obtain the peak value of the three-axis motor torque N3.

[0020] Further, when adjusting the position of the balancing center of gravity O" according to the selected balancing angle β, the balancing load block is moved in the horizontal direction or in a direction perpendicular to the horizontal plane, and the balancing center of gravity O" is adjusted by the change of the balancing load block's center of gravity.

[0021] Furthermore, when setting up a balancing load device, the pull rod is set to be hinged to the first adapter plate and the three-axis forearm at both ends, and the axis of the hinge axis is parallel to the first axis; when the heavy-load robot is set to an initial state, it is projected along the first axis to connect the first hinge point where the pull rod is hinged to the first adapter plate and the second axis, and the connecting line is parallel to the horizontal plane to facilitate measurement and calculation.

[0022] Furthermore, setting up a balancing load device also includes projecting along the first rotating axis to adjust the positions of the hinge points of the pull rod, the first adapter plate, and the three-axis forearm, so that a quadrilateral formed by sequentially connecting the first axis, the second axis formed by the second rotating axis, the first hinge point, and the second hinge point between the pull rod and the three-axis forearm is a parallelogram, so that during operation, the balancing load device maintains support for the three-axis forearm.

[0023] Furthermore, the parallelogram is a rectangle, and in an initial state, a line between the first axis and the second axis is perpendicular to a horizontal plane, so that a larger supporting force is obtained in the initial state.

[0024] Furthermore, the heavy-load robot is provided, also including a base and a large arm, so that the one-axis joint is arranged on the base and rotates around an axis perpendicular to the horizontal plane; one end of the large arm is hinged to the one-axis joint and rotates relative to it, and the three-axis small arm is hinged to the other end of the large arm, so that the support of the three-axis small arm by the balanced load device is realized with a simple structure.

[0025] Furthermore, when setting the load balancing device, it also includes setting the pull rod between the first adapter plate and the second adapter plate, and hinged to the first adapter plate and / or the second adapter plate to achieve torque transmission.

[0026] Furthermore, the heavy-load robot is set up to make the axis of the hinge axis between the one-axis joint and the second adapter plate, and the axis of the rotary axis of the upper arm rotating relative to the one-axis joint coincide with the second axis, so as to calculate and obtain the center of gravity position of the balanced load block.

[0027] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a six-axis palletizing robot in the prior art;

[0029] Figure 2 is a front view of the overall structure of the heavy-load robot of the present invention in an initial state in one embodiment;

[0030] Figure 31 is a front view of the overall structure of the heavy-load robot of the present invention in a state of a first limit swing angle θ in one embodiment;

[0031] Figure 4 1 is a front view of the overall structure of the heavy-load robot of the present invention in an embodiment when the robot is in a second limit swing angle ω state;

[0032] Figure 5 For along Figure 2 Partial section projection of midline ZZ section;

[0033] Figure 6 For along Figure 2 Partial section projection of the midline YY section;

[0034] Figure 7 A schematic flow chart of a method for setting a robot load balancing device of the present invention;

[0035] Figure 8 It is a schematic diagram of the process of obtaining the N3-X relationship curve in the present invention;

[0036] Fig. 9 Two N3-X relationship curves obtained in one embodiment of the present invention. DETAILED DESCRIPTION

[0037] The heavy-load robot of the present invention is provided with a robot load balancing device, which, on the one hand, moves the weight of the joint motor and the reducer to the one-axis joint to stabilize the center of gravity of the robot. On the other hand, through the torque balancing effect, the robot balancing device also reduces the output torque required by the motor driving the joint rotation, thereby reducing the size and weight of the motor and the reducer.

[0038] Specifically, see Figure 2 The robot load balancing device 100 of the present invention is arranged between the base 10 and one of the joints of the heavy load robot (not marked). During the handling process, the torque generated by the load balancing device 100 is opposite to the torque generated by the goods to be handled on the joint, thereby reducing the output torque of the motor driving the joint and preventing the robot from tipping over.

[0039] In this embodiment, the heavy-load robot is a six-axis robot, including a base 10, a one-axis joint 20, a large arm 30, a three-axis small arm 40, a four-axis rotating arm 50, a five-axis rotating arm 60, a six-axis terminal 70, a gripper (not shown) and a control unit (not shown). The base 10 is placed on a horizontal working platform. The one-axis joint 20 is installed above the base 10 and rotates around the axis of the rotating shaft perpendicular to the horizontal plane. One end of the large arm 30 is hinged to the one-axis joint 20 and can rotate around an axis parallel to the horizontal plane. The three-axis small arm 40 is hinged to the other end of the large arm 30 and can rotate around a first axis (not shown) parallel to the horizontal plane. The four-axis rotating arm 50 is installed on one side of the three-axis small arm 40 and can rotate around an axis parallel to the horizontal plane and perpendicular to the first axis. The five-axis rotating arm 60 is connected to one end of the four-axis rotating arm 50 away from the three-axis small arm 40 and can rotate coaxially with the four-axis rotating arm 50. The six-axis terminal 70 is located on the side of the five-axis rotating arm 60 away from the four-axis rotating arm 50, and it rotates relative to the five-axis rotating arm 60 around an axis parallel to the first axis. The gripper is fixed on the six-axis terminal 70 and moves with it to grab the goods to be transported. The motors and reducers that drive the one-axis joint 20, the big arm 30, the three-axis small arm 40, the four-axis rotating arm 50, the five-axis rotating arm 60 and the six-axis terminal 70 to rotate are respectively electrically connected to the control unit, and the control unit controls the output torque and steering of each motor respectively, and the control unit controls the opening and closing of the gripper. Under the control of the control unit, the one-axis joint 20, the big arm 30, the three-axis small arm 40, the four-axis rotating arm 50, the five-axis rotating arm 60 and the six-axis terminal 70 rotate around the axis respectively, so as to control the gripper to move to the position where the goods to be transported are placed for grabbing. Among them, the gripper can be a clamp such as a mechanical gripper, a pneumatic chuck, a magnetic suction cup, etc. Accordingly, the gripper driver may be a device provided with a motor, a cylinder, and an electromagnetic induction coupling circuit. The control unit may be a control device such as a computer with a CPU or a single-chip microcomputer. Since the gripper and the control unit are conventionally configured in the prior art, they will not be described in detail here.

[0040] Please refer to Figure 2 , Figure 5 and Figure 6, wherein the boom motor 31 and the boom reducer 32 driving the boom 30 to rotate are fixed on the one-axis joint 20, and the output shaft axes of the boom motor 31 and the boom reducer 32 coincide with each other. The boom 30 rotates relative to the one-axis joint 20 around an axis parallel to the first axis. The three-axis motor 41 and the three-axis reducer 42 driving the three-axis small arm 40 to rotate are fixedly arranged on the one-axis joint 20, and the output shaft axes of the three-axis motor 41 and the three-axis reducer 42 coincide with each other and are parallel to the first axis. The output shaft axis of the three-axis motor 41 is the second axis, that is, the first axis is parallel to the second axis.

[0041] The robot load balancing device 100 includes a first adapter plate 110 rotating with the three-axis motor 41, a second adapter plate 120 hinged to the one-axis joint 20, a pull rod 130, and a balance load block 140. One end of the pull rod 130 is hinged to the second adapter plate 120 and / or the first adapter plate 110, and the other end is hinged to the three-axis arm 40. The balance load block 140 is fixed to the end of the first adapter plate 110 away from the one-axis joint 20. Preferably, the balance load block 140 is fixedly connected to the first adapter plate 110 and the second adapter plate 120, and the second adapter plate 120 provides support for the balance load block 140; along the projection perpendicular to the horizontal plane, the balance load block 140 and the pull rod 130 are located between the first adapter plate 110 and the second adapter plate 120, and the pull rod 130 is hinged to the first adapter plate 110 and the second adapter plate 120 respectively by bolts or the like. The axis of the rotation axis of the first adapter plate 110, the axis of the articulation axis of the pull rod 130, the first adapter plate 11, and the three-axis small arm 40 are parallel to the first axis. The first adapter plate 110 drives the balancing load block 140 to rotate, and the second adapter plate 120 rotates accordingly and provides support for the balancing load block 140, and the balancing load block 140 can move vertically or horizontally relative to the first adapter plate 110 to adjust its center of gravity. With the rotation of the first adapter plate 110, the pull rod 130 moves up and down, and drives the three-axis small arm 40 and its load to rotate.

[0042] In this embodiment, the axis of rotation of the upper arm 30 relative to the one-axis joint 20 and the axis of the hinge axis of the second adapter plate 120 and the one-axis joint 20 are coincident with the second axis, and the first adapter plate 110 is fixedly connected to the output shaft of the three-axis reducer 42, so that the output torque of the three-axis motor 41 is transmitted to the first adapter plate 110 through the three-axis reducer 42, driving the balancing load block 140 to rotate around the output shaft axis of the three-axis motor 41, that is, to rotate around the second axis, and the second adapter plate 120 rotates accordingly, thereby driving the pull rod 130 to move up and down in a direction perpendicular to the horizontal plane. The pull rod 130 moves up and down to push the three-axis small arm 40 to rotate around the first axis, so as to realize the transmission of the output torque of the three-axis motor 41 to the three-axis small arm 40. Projected along the first axis, in the horizontal direction, the pull rod 130 is located between the balancing load block 140 and the three-axis motor 41, so that the torque generated by the balancing load block 140 is turned in the opposite direction to the torque generated by the three-axis motor 41, and the torque generated by the balancing load block 140 offsets part of the required output torque of the three-axis motor 41, reducing the output torque of the three-axis motor 41. The total load m is driven by the three-axis arm 40, and the total load m torque borne by the three-axis arm 40 is provided by the three-axis motor 41. Projected along the first axis, the first axis forms a first axis O1, the axis of the rotation axis of the three-axis motor 41 forms a second axis O2, the first hinge point between the second adapter plate 120 and the pull rod 130 is A, and the second hinge point between the three-axis arm 40 and the pull rod 130 is B. Adjust the hinge positions of the pull rod 130, the second adapter plate 120, and the three-axis small arm 40 so that the quadrilateral formed by sequentially connecting the first axis O1, the second hinge point B, the first hinge point A, and the second axis O2 is a parallelogram. The side length of the parallelogram can be set by selecting the optimal solution according to the length of the components of the heavy-load robot, the size of the space in which it is located, etc. Projected along the first axis, the balance angle β of the line connecting the second axis O2 and the center of gravity O" of the balancing load m1 of the balancing load block 140 relative to the horizontal plane is proportional to the output torque N3 of the three-axis motor. Adjusting the position of the balancing load block 140 and then changing the position of the center of gravity O" of the balancing load m1 can change the balance angle β, so that during the rotation of the three-axis small arm 40, the peak value of the output torque N3 of the three-axis motor 41 is minimized. Preferably, in the initial state, the line connecting the second axis O2 and the first hinge point A is parallel to the horizontal plane, and the parallelogram formed by the first axis O1, the second hinge point B, the first hinge point A and the second axis O2 is a rectangle, so as to facilitate the calculation of the balance angle β of the line connecting the center of gravity O" of the balanced load m1 and the second axis O2 relative to the horizontal plane.

[0043] Please refer to 2 to Figure 4 Based on the above-mentioned heavy-load robot and the structure of the robot balancing load device 100, the setting method of the robot balancing load device 100 is now described. It is particularly pointed out that in this embodiment, the robot used is a six-axis robot in the prior art, but the robot balancing load device 100 is not limited to the use in six-axis robots. Other three-axis, four-axis and other robots with similar structures are also applicable as long as there are joints with a structure that swings with an axis parallel to the horizontal plane to drive the goods to be transported to swing in a vertical plane perpendicular to the horizontal plane.

[0044] The method for setting the load balancing device 100 of the heavy load robot comprises the following steps:

[0045] Step S10: Set up the heavy-load robot and the balanced load device 100, connect the base 10, the one-axis joint 20, the upper arm 30, the three-axis small arm 40, the four-axis rotating arm 50, the five-axis rotating arm 60, the six-axis terminal 70 and the gripper in sequence, and install the three-axis motor 41 and the three-axis reducer 42 that drive the three-axis small arm 40 to rotate on the one-axis joint 20.

[0046] Step S20: Obtain the total load m that the joint supported by the load balancing device 100 needs to bear.

[0047] The total load m includes the weight of the joint itself, the weight of other joints driven by it, and the weight of the goods to be transported. In this embodiment, the total weight of the three-axis arm 40, the four-axis rotating arm 50, the five-axis rotating arm 60, the six-axis terminal 70, and the gripper is obtained, and the total weight of the goods to be transported is obtained according to the actual objects to be transported. The sum of the weights of the three-axis arm 40, the four-axis rotating arm 50, the five-axis rotating arm 60, the six-axis terminal 70, the gripper, and the goods to be transported is the total load m that the three-axis arm 40 needs to bear.

[0048] Step S30: adjusting the postures of the four-axis rotating arm 50, the five-axis rotating arm 60, the six-axis terminal 70 and the gripper so that the heavy-load robot is in an initial state, and obtaining the total center of gravity O' position of the total load m in the initial state.

[0049] In this embodiment, in the initial state, the line connecting the second axis O2 and the first hinge point A is parallel to the horizontal plane, and the line connecting the first axis O1 and the second axis O2 is perpendicular to the horizontal plane. At this time, projected along the first axis, the center of gravity of the total load m is O'.

[0050] Step S40: Calculate the total moment N1 generated by the total load m relative to the second axis in the initial state.

[0051] In the initial state, project along the first axis, measure the total load angle α of the line connecting the center of gravity O' of the total load m and the first axis O1 relative to the horizontal plane, and measure the distance between the center of gravity of the total load m and the first axis O1 as the total distance L. Combined with the moment calculation formula, the total moment N1 generated by the total load m relative to the first axis O1 is calculated according to the following formula:

[0052] N1=mg*cosα*L(1)

[0053] Furthermore, in this embodiment, the total moment N1 is generated by the total load m, and its direction is clockwise rotation around the first axis O2.

[0054] Step S50 : installing the load balancing device 100 on the heavy load robot, and obtaining the load balancing m1 of the load balancing device 100 .

[0055] The balancing load m1 is the sum of the weights of the first adapter plate 110 , the second adapter plate 120 , and the balancing load block 140 .

[0056] Step S60: Obtaining the center of gravity position of the balanced load m1 in the initial state.

[0057] Projected along the first axis, the balancing center of gravity of the balancing load m1 is O". When the weight of the balancing load block 140 is much larger than the first adapter plate 110 and the second adapter plate 120, for example, when the weight of the balancing load block 140 is more than 100 times the weight of the first adapter plate 110 and the second adapter plate 120, the weight of the first adapter plate 110 and the second adapter plate 120 can be ignored. At this time, the center of gravity of the balancing load block 140 can be regarded as the center of gravity O" of the balancing load m1.

[0058] Step S70: Calculating the balancing moment N2 generated by the balancing load m1 relative to the second axis O2 in the initial state.

[0059] Project along the first axis, measure the balance angle β of the line connecting the balance center of gravity O" and the second axis O2 relative to the horizontal plane, and the distance between the balance center of gravity O" and the first axis O1 is taken as the balance distance L1. Combined with the moment calculation formula, the balance moment N2 generated by the balance load m1 relative to the second axis O2 is calculated according to the following formula:

[0060] N2=m1g*cosβ*L1 (2)

[0061] The balancing torque N2 is generated by the balancing load m1, and its direction is counterclockwise rotation around the second axis O2.

[0062] Step S80: Obtain the three-axis motor torque N3 that drives the three-axis arm 40 to rotate in the initial state according to the total torque N1 and the balance torque N2.

[0063] Assume that the reduction ratio between the three-axis motor 41 and the three-axis reducer 42 is T, which is determined by the selected motor and reducer types. From the above analysis, the total torque N1 generated by the total load m and the balancing torque N2 generated by the balanced load m1 are opposite in direction, which can offset part of the required three-axis motor torque N3. Therefore, the three-axis motor torque N3 can be calculated by the following formula:

[0064] N3=(|N1|-|N2|)| / T=|(|mg*cosα*L|-|m1g*cosβ*L1|) / T(3)

[0065] Step S90: obtaining a calculation formula for the three-axis motor torque N3 when the three-axis arm 40 swings between extreme positions during operation.

[0066] Since the cargo to be transported remains basically unchanged each time the heavy-load robot is used to transport cargo, and the mass of the three-axis forearm 40, the four-axis rotating arm 50, the five-axis rotating arm 60, the six-axis terminal 70, and the gripper will not change, the total load m can be regarded as a constant value, and the total center of gravity O' rotates along a circle with the total distance L as the radius and the first axis O1 as the center during operation.

[0067] Projected along the first axis, the three-axis arm 40 rotates around the first axis O1 from the initial state, and the rotation angle is X degrees. When the three-axis arm 40 swings, clockwise rotation is the positive direction, and counterclockwise rotation is the negative direction. When the three-axis arm 40 swings to the positive and negative extreme positions, the angles between the line connecting the total center of gravity O' and the first axis O1 relative to the horizontal line are the first extreme swing angle θ and the second extreme swing angle ω, respectively. The magnitudes of the first extreme swing angle θ and the second extreme swing angle ω are determined by design requirements. The rotation angle X is between the first extreme swing angle θ and the second extreme swing angle ω.

[0068] As the three-axis small arm 40 swings, the rotation angle X changes. Since the quadrilateral formed by the first axis O1, the second axis O2, the first hinge point A and the second hinge point B remains a parallelogram, the angle between the center of gravity O" of the balanced load m1 and the first axis O1 relative to the horizontal plane also changes accordingly, so that the calculation formula between the dynamic three-axis motor torque N3 and the rotation angle X is obtained as follows:

[0069] N3=(|N1|-|N2|)| / T=|(|mg*cos(α-X)*L|-|m1g*cos(β+X)*L1|)| / T(4)

[0070] Step S100: According to the functional relationship of formula (4), the peak value of the three-axis motor torque N3 is obtained when the balancing angle β is different and the variation range of the rotation angle X is the same.

[0071] It can be seen from formula (4) that the total load m, the balanced load m1, the total distance L, the balanced distance L1, the total load angle α and the motor reduction ratio T are constant values. At the same balanced angle β, the three-axis motor torque N3 changes proportionally with the rotation angle X between the first limit swing angle θ and the second limit swing angle ω. With the rotation angle X as the horizontal coordinate and the three-axis motor torque N3 as the vertical coordinate, the N3-X relationship curve between the three-axis motor torque N3 and the rotation angle X under the same balanced angle β can be obtained, and the peak value of the three-axis motor torque N3 corresponding to the balanced angle β can be obtained. Accordingly, the balanced angle β is set to multiple different values ​​respectively, and the rotation angle X is kept within the first limit swing angle θ and the second limit swing angle ω. It is possible to obtain multiple N3-X relationship curves under multiple different balanced angles β with the same range of rotation angle X, and obtain the peak values ​​of the three-axis motor torque N3 under multiple different balanced angles β.

[0072] For details, please refer to Figure 8 , including the following steps:

[0073] Step S101: selecting an angle value β1 as the balancing angle β.

[0074] Step S102: Obtain, according to formula (4), an N3-X relationship curve when the rotation angle X changes between the first limit swing angle θ and the second limit swing angle ω when the equilibrium angle β=β1.

[0075] A coordinate diagram is established with the three-axis motor torque N3 as the ordinate and the rotation angle X as the abscissa, and an N3-X relationship curve is obtained when the equilibrium angle β=β1 and the rotation angle X change between the first limit swing angle θ and the second limit swing angle ω according to the functional relationship of formula (4).

[0076] Step S103: The balance angle β is increased in size in sequence and set to constant values ​​β2, β3, etc., and then step S102 is repeated to obtain different N3-X relationship curves, and different three-axis motor torque N3 peak values ​​are obtained from the different N3-X relationship curves.

[0077] Step S110 : comparing the N3 -X relationship curves, selecting the balance angle β corresponding to the curve with the smallest peak value of the three-axis motor torque N3 to set the balanced load device 100 .

[0078] When setting up the balancing load device 100, the balancing load device 100 is moved horizontally or vertically relative to the first adapter plate 110, so that the distance from the center of gravity of the balancing load device 100 to the second axis O2 changes horizontally or vertically to adjust the balancing angle β.

[0079] In this embodiment, when the above-mentioned heavy-load robot balanced load device setting method is used, the heavy-load robot is set, and the total load m=1300kg, the balanced load m1=550kg, the total load angle α=14.4°, and the balanced angle β=9° are measured; the first limit swing angle θ=-20°, and the second limit swing angle ω=60°, that is, projected along the first axis direction, starting from the initial state, the maximum angle of the three-axis arm 40 rotating counterclockwise around the first axis O1 is 20°, and the maximum angle of the clockwise rotation is 60°; the total load minimum distance L=1039mm, the total balanced load minimum distance L1=971mm, the motor reduction ratio T of the three-axis arm 40 is 175, which is substituted into the formula (4), and the three-axis arm 40 is swung between -20° and 60°. After performing steps S10 to S100, multiple N3-X relationship curves are obtained, of which two curves are as follows: Fig. 9 The curve L and curve M are shown. Fig. 9It can be seen that the peak value of curve L is smaller than the peak value of curve M, and the balance angle β corresponding to the curve L is 18.49°. The position of the balanced load device 100 is adjusted so that when the center of gravity O" of the balanced load device 100 is in the initial state, the balance angle β between the line connecting it and the center of rotation O1 of the upper arm relative to the horizontal plane is 18.49°, thereby achieving the purpose of reducing the required torque N3 of the three-axis motor. Preferably, mutually engaged protrusions and grooves extending in the horizontal square or vertical direction are provided between the balanced load device 100 and the second adapter plate 120 to facilitate the adjustment between the balanced load device 100 and the second adapter plate 120. . In this embodiment, for the same balance angle β, starting from the initial state, the rotation angle X can be increased or decreased in units of 5° until the first limit swing angle θ or the second limit swing angle ω is reached, thereby obtaining multiple motor torque N3 values. In the N3-X coordinate diagram, two adjacent points are connected to obtain the N3-X relationship curve under the same balance angle β; for the same rotation angle X, the balance angle β changes in units of 5°, thereby obtaining multiple different N3-X relationship curves formed in the N3-X coordinate diagram. In addition, in actual work, different balance angle β or rotation angle X change values ​​can be selected according to accuracy requirements, etc.

[0080] It is particularly pointed out that in the present embodiment, the balancing load device 100 is connected between the three-axis arm 40 and the one-axis joint 20, and provides support for the rotation of the three-axis arm 40, thereby reducing the output torque of the motor that drives the three-axis arm 40 to rotate. However, according to actual needs, the balancing load device 100 can also be connected to different joints to provide support, as long as the torque generated by the balancing load device 100 is opposite to the output torque of the motor that drives the joint to rotate.

[0081] Compared with the prior art, the method for setting up a balanced load device of a heavy-load robot of the present invention has the following advantages:

[0082] (1) It can minimize the required total load torque peak, making the required motor and reducer small in size and light in weight, thereby improving the flexibility of the robot;

[0083] (2) The adjustment is simple and easy to implement, and can be applied to the adjustment of most heavy-load robots.

[0084] (3) The calculation is simple. With the help of computers, the required result curve can be obtained intuitively and quickly, and the required data can be obtained accurately.

[0085] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for setting a load balancing device of a heavy load robot, characterized in that: The following steps are included A heavy-load robot is provided, comprising a one-axis joint located on a horizontal plane, a three-axis forearm located above the one-axis swivel seat, and a three-axis motor installed on the one-axis joint; the three-axis forearm rotates around a first axis parallel to the horizontal plane; the output axis of the three-axis motor is a second axis; the first axis is parallel to the second axis; Obtain the total load m borne by the three-axis forearm; A load balancing device is provided, including a first adapter plate, a pull rod and a load balancing block; so that under the drive of the three-axis motor, the first adapter plate drives the three-axis forearm to rotate around the first axis through the pull rod; Obtaining a balancing load m1, including the weight of the first adapter plate and the balancing load block; the moment generated by the balancing load m1 relative to the second axis is opposite in direction to the moment generated by the total load m relative to the first axis; Setting the heavy-load robot to an initial state; Project along the first axis, in the initial state, obtain the position of the total center of gravity O' of the total load m and the distance L between the total center of gravity O' and the first axis formed by the first axis, and measure the total load angle α of the line between the total center of gravity O' of the total load m and the first axis relative to the horizontal plane; Project along the first axis, in the initial state, obtain the position of the balancing center of gravity O" of the balancing load m1 and the distance L1 between the balancing center of gravity O" and the second axis formed by the second axis, and measure the balancing angle β of the line connecting the balancing center of gravity O" and the second axis relative to the horizontal plane; Starting from the initial state, the three-axis forearm is rotated around the first axis, and the angle it rotates is the rotation angle X. The peak value of the three-axis motor torque N3 at different balance angles β is obtained according to the following formula: N3= |(|mg*cos(α-X)*L|-|m1g*cos(β+X)*L1|)| / T, where T is the reduction ratio between the three-axis motor and the reducer connected thereto; The peak values ​​of the three-axis motor torque N3 at different balancing angles β are compared, the balancing angle β corresponding to the minimum peak value of the three-axis motor torque N3 is selected, and the position of the balancing center of gravity O" is adjusted according to the selected balancing angle β.

2. The method for setting up a load balancing device for a heavy load robot according to claim 1, characterized in that: The load balancing device further comprises a second adapter plate hinged to the one-axis joint, wherein the hinge axis of the one-axis joint and the second adapter plate is parallel to the first axis; and the load balancing block is installed between the first adapter plate and the second adapter plate.

3. The method for setting up a load balancing device for a heavy load robot according to claim 1, characterized in that: Obtaining the peak value of the three-axis motor torque N3 at different balancing angles β according to the formula includes the following steps: Angle value β1 is selected as the equilibrium angle β, and the rotation angle X varies between a first limit swing angle θ and a second limit swing angle ω; Establish a coordinate diagram with the three-axis motor torque N3 as the ordinate and the rotation angle X as the abscissa, calculate and obtain the N3-X relationship curve when the balance angle β=β1 and the rotation angle X changes between the first limit swing angle θ and the second limit swing angle ω according to the above formula, and obtain the peak value of the three-axis motor torque N3 when the balance angle β=β1 from the N3-X relationship curve; The balance angle β is set to different angle values, and different N3-X relationship curves corresponding to different balance angles β are obtained when the rotation angle X is at the first limit swing angle θ and the second limit swing angle ω, and the three-axis motor torque N3 peak values ​​in the different N3-X relationship curves corresponding to the different balance angles β are obtained.

4. The method for setting up a load balancing device for a heavy load robot according to claim 1, characterized in that: When the position of the balancing center of gravity O" is adjusted according to the selected balancing angle β, the balancing load block is moved in a horizontal direction or a direction perpendicular to the horizontal plane.

5. The method for setting up a load balancing device for a heavy load robot according to claim 1, characterized in that: When setting up the load balancing device, the pull rod is set to be hinged to the first adapter plate and the three-axis arm at both ends, and the axis of the hinge shaft is parallel to the first axis; When the heavy-load robot is set to an initial state, a line projected along the first axis connecting the first hinge point where the pull rod is hinged to the first adapter plate and the second axis is parallel to a horizontal plane.

6. The method for setting up a load balancing device for a heavy load robot according to claim 5, characterized in that: Setting up a load balancing device also includes projecting along the first axis to adjust the hinge point positions of the pull rod, the first adapter plate, and the three-axis arm so that a quadrilateral formed by sequentially connecting the first axis, the second axis formed by the second axis, the first hinge point, and the second hinge point between the pull rod and the three-axis arm is a parallelogram.

7. The method for setting up a load balancing device for a heavy load robot according to claim 6, characterized in that: The parallelogram is a rectangle, and in an initial state, a line between the first axis and the second axis is perpendicular to a horizontal plane.

8. The method for setting up a load balancing device for a heavy load robot according to claim 2, characterized in that: A heavy-load robot is provided, which also includes a base and a large arm, so that the one-axis joint is provided on the base and rotates around an axis perpendicular to the horizontal plane; one end of the large arm is hinged to the one-axis joint and rotates relative to it, and the three-axis small arm is hinged to the other end of the large arm.

9. The method for setting up a load balancing device for a heavy load robot according to claim 8, characterized in that: When setting the load balancing device, the method further includes setting the pull rod between the first adapter plate and the second adapter plate, and hingedly connecting the pull rod to the first adapter plate and / or the second adapter plate.

10. The method for setting up a load balancing device for a heavy load robot according to claim 8, characterized in that: Setting up the heavy-load robot also includes making the axis of the hinge axis between the one-axis joint and the second adapter plate, the axis of the rotary axis of the upper arm rotating relative to the one-axis joint coincide with the second axis.

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