CN116652920B

CN116652920B - Rope driving robot, rope differential mechanism and rope driving robot steel rope tensioning detection method

Info

Publication number: CN116652920B
Application number: CN202310953810.8A
Authority: CN
Inventors: 李子健; 付杰; 周玉康
Original assignee: Easton Nanjing Medical Technology Co ltd
Current assignee: Easton Nanjing Medical Technology Co ltd
Priority date: 2023-08-01
Filing date: 2023-08-01
Publication date: 2024-02-23
Anticipated expiration: 2043-08-01
Also published as: CN116652920A

Abstract

The invention discloses a rope driving robot, a rope differential mechanism and a rope tensioning detection method of the rope driving robot, wherein the robot has a plurality of degrees of freedom, and the robot comprises: a base, a first section, a second section, a third section, a fourth section, a fifth section, a sixth section, and a seventh section; the robot has seven joints and seven degrees of freedom, the first joint to the sixth joint of the robot are driven by a rope driving mechanism, and the seventh joint is driven by a rope driving mechanism or a gear mechanism; the rope drive mechanism comprises a steel rope and a pulley driven by the steel rope, and the pulley is provided with a band-type brake and an encoder. The invention has more stable positions at each joint, can detect the actual displacement at each joint, and is beneficial to improving the accuracy of robot control.

Description

Rope driving robot, rope differential mechanism and rope driving robot steel rope tensioning detection method

Technical Field

The invention relates to the technical field of robots, in particular to a rope driving robot, a rope differential mechanism and a rope tensioning detection method of the rope driving robot.

Background

Compared with the traditional cooperative robot, the rope-driven robot has the advantages of being free of gear clearance, small in friction force, light in arm, safe to use and the like. Most of the driving units are concentrated to the base through the rope drive, so that the inertia of the tail end is reduced, and the robot has extraordinary reversible driving capability. The earliest 4-degree-of-freedom rope driven robots were proposed by J. Kenneth Salisbury, jr. And William T. Townsend, 1993, and described in patent documents J. Kenneth Salisbury, jr and William T. Townsend, compact cable transmission with cable differential, U.S. Pat. No. 5207114. The rotation of the shafts of two motors which are arranged in parallel is converted into pitching and yawing motions through a rope-driven differential device.

Based on this model, U.S. Barrett, inc. proposed a 3-degree-of-freedom NON-exoskeleton rehabilitation robot of similar rope drive structure in 2018, described in patent documents William T, townsend, david Wilkinson, alexander Jenko, rvind Ananthanarayanan and James Pattern, MULTI-ACTIVE-AXIS, NON-EXOSKELETAL REHABILITATION DEVICE, U.S. 10130546B 2.

However, the following problems exist in the two prior arts:

1) Since only one single-turn absolute value magnetic encoder is installed at the motor end. Before starting up each time, the controller cannot know the current actual position of the joint end. Thus, the user is required to manually swing each joint of the robot back to a predefined Home position. The method for placing the Home position of the mechanical arm by only manual observation is easy to cause position deviation and increases the complexity of use and operation.

2) Positional deviations are caused by the transmission of steel ropes (described in reference [1988] The Efficiency Limit of Belt and Cable Drives), and the relationship between the robot end load and joint position error is nonlinear and there is a hysteresis effect. Therefore, the position of the joint end is estimated only by the reading of the encoder at the motor end and the transmission ratio, so that the position control generates larger deviation, and the rope-driven robot cannot be suitable for occasions with higher requirements on the position precision.

3) When the robot is powered down accidentally, the mechanical arm will slowly drop to the mechanical limit, but will not lock the position automatically. This may present a safety risk in certain applications such as rehabilitation, medical treatment, etc.

Disclosure of Invention

The invention provides a rope-driven robot, which has the advantages that the positions of all joints of the robot are more stable, the actual displacement of all joints can be detected, and the control accuracy of the robot is improved.

The technical scheme of the invention is as follows:

in one aspect, the present invention provides a rope-driven robot, wherein the robot has a plurality of joints to provide a plurality of degrees of freedom, at least one joint of the robot is driven by a rope-driving mechanism, the rope-driving mechanism comprises a motor, a steel rope and a pulley, the motor drives the pulley to rotate through the steel rope, and the pulley drives the joint of the robot to move; the motor is provided with a motor side encoder, and the pulley is provided with a joint side encoder.

Further, in the rope driving mechanism, a motor side band-type brake is arranged on the motor, or a joint side band-type brake is arranged on the pulley.

Further, the robot having seven joints provides seven degrees of freedom, the robot comprising:

a base;

a first section disposed on the base and controllable to rotate about a first axis to form a first joint to provide a first degree of freedom;

a second section disposed on the first section and controllable to rotate about a second axis to form a second joint to provide a second degree of freedom;

the third section is arranged on the second section and can rotate around a third axis in a controlled manner to form a third joint so as to provide a third degree of freedom;

a fourth section disposed on the third section and controllable to rotate about a fourth axis to form a fourth joint to provide a fourth degree of freedom;

a fifth section disposed on the fourth section and controllable to rotate about a fifth axis to form a fifth joint to provide a fifth degree of freedom;

a sixth section disposed on the fifth section and controllable to rotate about a sixth axis to form a sixth joint to provide a sixth degree of freedom;

and a seventh section disposed on the sixth section and controllable to rotate about a seventh axis to form a seventh joint to provide a seventh degree of freedom;

the first joint to the sixth joint of the robot are driven by a rope driving mechanism, and the seventh joint is driven by a rope driving mechanism or a gear mechanism.

Further, the first axis is perpendicular to the plane where the base is located, and the first axis, the second axis, the third axis, the fourth axis, the fifth axis, the sixth axis and the seventh axis are sequentially perpendicular.

Further, the rope driving mechanism comprises a first rope driving mechanism, the first rope driving mechanism comprises a first motor and a first output pulley, the first motor and the first output pulley are driven by a steel rope, and a joint output shaft is arranged on the first output pulley and is used for being connected with a joint of the robot;

the first joint, the fourth joint and the seventh joint of the robot are driven by a group of first rope driving mechanisms respectively.

Further, the output axis of the first motor is parallel to the centerline of the first output pulley.

Further, a motor side encoder is arranged on the first motor, and a joint side encoder is arranged on the first output pulley;

the first motor is provided with a motor side band-type brake, or the first output pulley is provided with a joint side band-type brake.

Further, the rope driving mechanism comprises a first rope differential mechanism, the first rope differential mechanism comprises a left input motor, a left input pulley, a second output pulley, a right input pulley and a right input motor, the left input motor is in transmission connection with the left input pulley through a steel rope, the right input pulley is in transmission connection with the right input motor through the steel rope, the second output pulley is respectively coupled with the left input pulley and the right input pulley through the steel rope, and a joint output shaft is arranged on the second output pulley and is used for being connected with a joint of the robot;

the second joint and the third joint of the robot are driven by a group of first rope differentials, the first rope differentials are arranged in the first sections, the second output pulleys are arranged in the second sections, and joint output shafts on the second output pulleys are connected with the third sections.

Further, the output axis of the left input motor is parallel to the center line of the left input pulley, the output axis of the right input motor is parallel to the center line of the right input pulley, the center lines of the left input pulley and the right input pulley are collinear, and the second output pulley is perpendicular to the center line of the left input pulley;

the left input pulley, the second output pulley and the right input pulley are provided with multistage steps for connecting steel ropes.

Further, motor side encoders are arranged on the left input motor and the right input motor, and joint side encoders are arranged on the second output pulley, the left input pulley and the right input pulley;

and motor side band-type brakes are arranged on the left input motor and the right input motor, or joint side band-type brakes are arranged on the second output pulley, the left input pulley and the right input pulley.

Further, the rope driving mechanism comprises a second rope differential mechanism, the second rope differential mechanism comprises an upper input motor, an upper input pulley, a third output pulley, a lower input pulley and a lower input motor, the upper input motor is connected with the upper input pulley through a first transmission mechanism, the lower input pulley is connected with the lower input motor through a second transmission mechanism, the third output pulley is respectively coupled with the upper input pulley and the lower input pulley through steel ropes, a connecting plate is arranged on the third output pulley and is used for being connected with a joint of the robot, and a fourth output shaft perpendicular to the axis of the third output pulley is arranged on the connecting plate;

the fifth joint and the sixth joint of the robot are driven by a group of second rope differentials, the second rope differentials are arranged on a fourth section, the fifth section comprises the connecting plate, and the fourth output shaft is connected with the sixth section.

Further, the first transmission mechanism and the second transmission mechanism are three-level steel rope transmission mechanisms, and comprise a first transmission shaft section and a second transmission shaft section;

in the first transmission mechanism, an upper input motor, a first transmission shaft section, a second transmission shaft section and an upper input pulley are sequentially connected through steel rope transmission;

in the second transmission mechanism, a lower input motor, a first transmission shaft section, a second transmission shaft section and a lower input pulley are sequentially connected through steel rope transmission.

Further, the center lines of the upper input pulley and the lower input pulley are collinear, and the third output pulley is perpendicular to the center line of the upper input pulley;

the upper input pulley and the third output pulley are provided with multi-stage steps for connecting steel ropes;

the upper input pulley and the lower input pulley are arranged in parallel, a central shaft penetrating through the upper input pulley is arranged on the lower input pulley, and the tail end of the central shaft is provided with multiple steps and is coupled with the upper steps of the third output pulley through steel ropes.

Further, motor side encoders are arranged on the upper input motor and the lower input motor, and joint side encoders are arranged on the third output pulley, the upper input pulley and the lower input pulley;

and motor side band-type brakes are arranged on the upper input motor and the lower input motor, or joint side band-type brakes are arranged on the third output pulley, the upper input pulley and the lower input pulley.

The robot part joint is driven by the rope differential mechanism, and the rope differential mechanism can change the transmission direction, so that the robot part joint is beneficial to being applied to a robot and is suitable for the structural space of the robot; if the robot adopts the scheme of joint series connection, the output moment of one joint motor is always required to bear the weight of the stator part of the next joint motor, and the rope differential mechanism enables the output force of the two motors to be fully applied to the output shaft, so that the output capacity of the motors is more effectively utilized. In terms of inertia, the rope differential has two parallel placed input motors, whereas if only one motor is used to output the same torque, the outer diameter of the rotor of the motor must be larger, with an inertia greater than the equivalent inertia of the two motors of the rope differential. The smaller motor inertia means that the robot has better reverse driving capability, and the tail end of the robot is more flexible when being dragged freely.

On the other hand, the invention provides a rope differential mechanism, which comprises an upper input motor, an upper input pulley, a third output pulley, a lower input pulley and a lower input motor, wherein the upper input motor is connected with the upper input pulley through a first transmission mechanism, the lower input pulley is connected with the lower input motor through a second transmission mechanism, the third output pulley is respectively coupled with the upper input pulley and the lower input pulley through a steel rope, an output shaft or a connecting plate is arranged on the third output pulley, and a fourth output shaft perpendicular to the axis of the third output pulley is arranged on the connecting plate.

In another aspect, the present invention provides a method for detecting tension of a steel rope of a rope-driven robot, at least one joint of the robot is driven by a rope-driven mechanism, the rope-driven mechanism includes a motor, a pulley and a steel rope, a motor-side encoder is provided on the motor, a joint-side encoder is provided on the pulley, a motor-side band-type brake is provided on the motor or a joint-side band-type brake is provided on the pulley, the method includes:

acquiring data of the joint side encoder and the motor side encoder, converting the data to the same side according to the transmission ratio, and calculating absolute values of data difference values measured by the joint side encoder and the motor side encoder;

fitting out a functional relation between the tension of the steel rope and the difference values of the joint side encoder and the motor side encoder, and calculating the tension of the steel rope according to the absolute value of the difference values of the joint side encoder and the motor side encoder; if the tension of the steel rope is greater than or equal to a set threshold value, judging that the steel rope is not loosened, and running a robot control program; if the tension of the steel rope is smaller than a set threshold value, the steel rope is judged to be loosened, the robot is controlled to be powered off, and the motor side band-type brake or the joint side band-type brake is started.

In summary, the beneficial effects of the invention are as follows:

1. according to the invention, in the rope drive mechanism, the band-type brake and the encoder are arranged on the pulleys, so that the posture position of each joint of the robot is accurately known, the precise control of the robot is facilitated, the arranged band-type brake can lock the posture of the joint of the robot when the robot is stopped or powered off, and the working safety of the robot is improved;

2. according to the invention, the robot provides the seventh degree of freedom as the redundant degree of freedom, so that the robot has multiple solutions to the target position, and obstacle avoidance of the robot is facilitated;

3. the invention provides a rope differential mechanism, which realizes the realization mode of providing two degrees of freedom of movement in a smaller space and realizes the wrist joint design of a robot;

4. through real-time calculation wire rope tensioning force, when the tensioning force is low, the user is prompted to start the wire rope tensioning program, and when the wire rope is loosened or broken, the band-type brake is timely started to prevent the mechanical arm from falling.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of a first rope drive mechanism according to the present invention;

fig. 3 is a schematic representation of the first rope differential of the present invention;

fig. 4 is a schematic diagram of a second rope differential of the present invention;

FIG. 5 is a schematic diagram of the power output of a robot wrist according to the present invention;

FIG. 6 is a schematic view of a seventh joint of the robot of the present invention;

FIG. 7 is a schematic view of a seventh joint of the robot of the present invention using a gear drive;

FIG. 8 is a schematic diagram of a method for detecting the tension of a steel rope of a rope driven robot in the invention;

fig. 9 is a control schematic of the robot according to the present invention.

100, a base; 200. a first section; 300. a second section; 400. a third section; 500. a fourth section; 600. a fifth section; 700. a sixth section; 800. a seventh section; 900. a first rope drive mechanism; 901. a first motor; 902. a first output pulley; 1000. a steel rope; 1100. a motor side band-type brake; 1200. a motor-side encoder; 1300. a joint side band-type brake; 1400. a joint side encoder; 1500. a first rope differential; 1501. a left input motor; 1502. a right input motor; 1503. a left input pulley; 1504. a right input pulley; 1505. a second output pulley; 1600. a second rope differential; 1601. an upper input motor; 1602. a lower input motor; 1603. an upper input pulley; 1604. a lower input pulley; 1605. a central shaft; 1606. a third output pulley; 1607. a connecting plate; 1608. a fourth output shaft; 1700. an input gear; 1800. an intermediate gear; 1900. an output gear.

Description of the embodiments

The following describes in detail the embodiments of the present invention with reference to the drawings.

It should be noted that, in the present invention, "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the specific order thereof. "upper", "lower", "left", "right", etc. are for descriptive purposes only and not to limit specific orientations thereof. It should be understood that the descriptions of "horizontal", "vertical", "parallel", and the like in the present invention do not represent absolute positional relationships, but include positional relationships of certain process errors and control errors.

Examples: referring to fig. 1, an embodiment of the present invention provides a rope-driven robot having a plurality of joints to provide a plurality of degrees of freedom, at least one joint of the robot being driven with a rope-driving mechanism including a motor, a steel rope 1000, and a pulley, the motor driving the pulley to rotate through the steel rope 1000, the pulley driving the joint of the robot to move; the motor is provided with a motor-side encoder 1200, and the pulley is provided with a joint-side encoder 1400. In the rope drive mechanism, a motor side band-type brake 1100 is arranged on a motor, or a joint side band-type brake 1300 is arranged on a pulley.

The robot having seven joints providing seven degrees of freedom, the robot comprising:

a base 100, the base 100 being horizontally disposed as a base of the robot, having a space inside for disposing a controller and a wire harness;

the first section 200 is disposed on the base 100 and can be controlled to rotate around a first axis to form a first joint, so as to provide a first degree of freedom J1, wherein the first axis is in a vertical state and is perpendicular to a plane of the base 100;

a second section 300 disposed on the first section 200 and controllable to rotate about a second axis to form a second joint to provide a second degree of freedom J2;

a third section 400 disposed on the second section 300 and controllable to rotate about a third axis to form a third joint to provide a third degree of freedom J3;

a fourth segment 500 disposed on the third segment 400 and controllable to rotate about a fourth axis to form a fourth joint to provide a fourth degree of freedom J4;

a fifth section 600 disposed on the fourth section 500 and controllable to rotate about a fifth axis to form a fifth joint to provide a fifth degree of freedom J5;

a sixth section 700 disposed on the fifth section 600 and controllable to rotate about a sixth axis to form a sixth joint to provide a sixth degree of freedom J6; the combination of the fifth joint and the sixth joint is a wrist joint of the robot;

and a seventh segment 800 disposed on the sixth segment 700 and controllable to rotate about a seventh axis to form a seventh joint to provide a seventh degree of freedom J7.

The seventh section 800 also serves as a tip of the robot for carrying the apparatus.

The first joint to the sixth joint of the robot are driven by a rope driving mechanism, and the seventh joint is driven by the rope driving mechanism. The rope driving mechanism comprises a steel rope 1000 and a pulley driven by the steel rope 1000, and the pulley is provided with a band-type brake and an encoder.

The first axis is perpendicular to the plane of the base 100, and the first axis, the second axis, the third axis, the fourth axis, the fifth axis, the sixth axis and the seventh axis are perpendicular in order, that is, the J1 axis, the J2 axis, the J3 axis, the J4 axis, the J5 axis, the J6 axis and the J7 axis are perpendicular in order.

Referring to fig. 2, the rope driving mechanism includes a first rope driving mechanism 900, the first rope driving mechanism 900 includes a first motor 901 and a first output pulley 902, the first motor 901 and the first output pulley 902 are driven by a steel rope 1000, and a joint output shaft is disposed on the first output pulley 902 and is used for connecting with a certain joint of the robot; the first joint, the fourth joint and the seventh joint of the robot are driven by a group of first rope driving mechanisms 900 respectively, namely, the J1 shaft, the J4 shaft and the J7 shaft are driven by the first rope driving mechanisms 900, and correspondingly, the robot is provided with motors M1, M4 and M7. The output axis of the first motor 901 is parallel to the center line of the first output pulley 902. The first motor 901 is provided with a motor-side encoder 1200, and the first output pulley 902 is provided with a joint-side encoder 1400. The first motor 901 is provided with a motor side band-type brake 1100, or the first output pulley 902 is provided with a joint side band-type brake 1300.

Referring to fig. 3, the rope driving mechanism includes a first rope differential 1500, the first rope differential 1500 includes a left input motor M2, a left input pulley 1503, a second output pulley 1505, a right input pulley 1504 and a right input motor M3, the left input motor 1501 is in transmission connection with the left input pulley 1503 through a steel rope 1000, the right input pulley 1504 is in transmission connection with the right input motor 1502 through the steel rope 1000, the second output pulley 1505 is coupled with the left input pulley 1503 and the right input pulley 1504 through the steel rope 1000, and a joint output shaft is arranged on the second output pulley 1505 and is used for connecting a joint of the robot. The second and third joints of the robot are driven by a set of first rope differentials 1500, i.e. the J2 and J3 axes are driven by the first rope differential 1500, the first rope differential 1500 is mounted in the first section 200, the second output pulley 1505 is mounted in the second section 300, and the joint output shaft on the second output pulley 1505 is connected to the third section 400.

The output axis of the left input motor 1501 is parallel to the center line of the left input pulley 1503, the output axis of the right input motor 1502 is parallel to the center line of the right input pulley 1504, the center lines of the left input pulley 1503 and the right input pulley 1504 are collinear, and the second output pulley 1505 is perpendicular to the center line of the left input pulley 1503; the left input pulley 1503, the second output pulley 1505 and the right input pulley 1504 are provided with multiple steps for connecting the steel ropes 1000. In this embodiment, four steps are provided on the left input pulley 1503, the right input pulley 1504 and the second output pulley 1505, wherein two steps on the second output pulley 1505 are coupled with the left input pulley 1503, and the other two steps are coupled with the right input pulley 1504.

When the left input pulley 1503 and the right input pulley 1504 rotate in the same direction, the joint output shaft mounted on the second output pulley 1505 realizes pitching motion (i.e., swings up and down); when the left input pulley 1503 and the right input pulley 1504 rotate in opposite directions, the articulation output shaft mounted on the output pulley effects yaw motion (i.e., side-to-side rotation).

The left input motor 1501 and the right input motor 1502 are provided with a motor side band-type brake 1100 and a motor side encoder 1200 for emergency braking and position detection; the second output pulley 1505 is provided with a joint-side band-type brake 1300 and a joint-side encoder 1400 for emergency braking and position detection. In other embodiments, band brakes and encoders may be provided on left input pulley 1503 and right input pulley 1504 as well.

The encoders and band-type brakes mounted on the left input pulley 1503 and the right input pulley 1504 realize the position detection and emergency braking of the pitch direction of the output shaft of the robot joint, and the encoders and band-type brakes mounted on the second output pulley 1505 realize the position detection and emergency braking of the yaw direction of the output shaft of the robot joint.

The J2 and J3 axes of the robot adopt the transmission mode.

Referring to fig. 4-5, the rope driving mechanism includes a second rope differential 1600, the second rope differential 1600 includes an upper input motor M5, an upper input pulley 1603, a third output pulley 1606, a lower input pulley 1604 and a lower input motor M6, the upper input motor 1601 is connected with the upper input pulley 1603 through a first transmission mechanism, the lower input pulley 1604 is connected with the lower input motor 1602 through a second transmission mechanism, the third output pulley 1606 is coupled with the upper input pulley 1603 and the lower input pulley 1604 through a steel rope 1000, a connection board 1607 is provided on the third output pulley 1606 for connecting with a joint of the robot, and a fourth output shaft 1608 perpendicular to the axis of the third output pulley 1606 is provided on the connection board 1607. The fifth and sixth joints of the robot are driven with a set of second rope differentials 1600, i.e. the wrist joints (J4 and J5 axes) of the robot are driven by the second rope differentials 1600 (driven by M5, M6). The second rope differential 1600 is mounted on the fourth section 500, the fifth section 600 comprising the connection plate 1607, the fourth output shaft 1608 being connected to the sixth section 700.

The first transmission mechanism and the second transmission mechanism are three-level steel rope 1000 transmission mechanisms, and comprise a first transmission shaft section and a second transmission shaft section; the first transmission shaft section and the second transmission shaft section are stepped shafts, so that transmission speed reduction is realized.

In the first transmission mechanism, an upper input motor 1601, a first transmission shaft section, a second transmission shaft section, and an upper input pulley 1603 are sequentially connected by transmission of a steel cable 1000.

In the second transmission mechanism, the lower input motor 1602, the first transmission shaft section, the second transmission shaft section and the lower input pulley 1604 are sequentially connected by transmission of the steel cable 1000.

The centerlines of the upper input pulley 1603 and the lower input pulley 1604 are collinear, and the third output pulley 1606 is perpendicular to the centerline of the upper input pulley 1603; the upper input pulley 1603 and the third output pulley 1606 are provided with multiple steps for connecting the steel cable 1000. The upper input pulley 1603 and the lower input pulley 1604 are arranged in parallel and stacked, and can rotate relatively to each other, a central shaft 1605 passing through the upper input pulley 1603 is provided on the lower input pulley 1604, and a multi-stage step is provided at the end of the central shaft 1605 and is coupled with the upper steps of the third output pulley 1606 through the steel cable 1000. In this embodiment, the steps at the end of the central shaft 1605 are three-level, the steps on the upper input pulley 1603 are three-level, and the steps on the third output pulley 1606 are three-level. Of the three steps on the third output pulley 1606, one is coupled only to the step on the upper input pulley 1603, the other is coupled only to the step at the end of the central shaft 1605, and the remaining intermediate steps are coupled to both the steps on the upper input pulley 1603 and the end of the central shaft 1605.

The connecting plate 1607 is L-shaped for converting the transmission direction, and when the upper input pulley 1603 and the lower input pulley 1604 rotate in the same direction, the L-shaped connecting plate 1607 mounted on the third output pulley 1606 swings horizontally and horizontally, so that the motion of the robot joint output shaft swings horizontally; when the upper input pulley 1603 and the lower input pulley 1604 are rotated in opposite directions, the L-shaped connection plate 1607 mounted on the third output pulley 1606 is rotated up and down, and thus the movement of the robot joint output shaft is also rotated up and down.

The upper input motor 1601 and the lower input motor 1602 are provided with a motor side band-type brake 1100 and a motor side encoder 1200; the third output pulley 1606 and the fourth output shaft 1608 are provided with a joint-side band brake 1300 and a joint-side encoder 1400. Realize the position detection and emergency braking of the up-and-down and horizontal rotation of the robot joint output shaft.

In this embodiment, the coupling mode of the steel rope 1000 between the pulleys adopts the coupling mode disclosed in patent document US5207114, wherein a winding mode of the steel rope 1000 is specifically disclosed, so that the direction of power output can be changed by the transmission of the steel rope 1000.

In the rope driving mechanism of this embodiment, the joint-side band-type brake 1300 and the motor-side band-type brake 1100 are alternatively selected, i.e. the band-type brake is installed on the motor side or the band-type brake is installed on the pulley side.

It will be appreciated that in the present invention, the robot has a space for installing the rope drive mechanism in each section, and a support structure for supporting each pulley, and at the joint position, there are provided bearings and the like, which are means existing in the art.

Referring to fig. 6-7, a seventh joint is integrally provided with sixth section 700 and is coupled to fourth output shaft 1608. The seventh joint increases a rotational degree of freedom for the tail end of the robot, is coaxial with the rotation generated by the 5 th joint, provides redundant degrees of freedom, and improves the obstacle avoidance capability of the robot.

In other embodiments, the seventh joint is not driven by a rope drive mechanism, but is driven by a gear mechanism, and in particular, the gear mechanism includes an input gear 1700, an intermediate gear 1800, and an output gear 1900, where the input gear 1700 is connected to an output shaft of an input motor, and the output gear 1900 is disposed on the seventh section 800.

The invention also provides a method for detecting the tensioning of the steel rope 1000 of the rope-driven robot, at least one joint of the robot is driven by a rope-driven mechanism, the rope-driven mechanism comprises a motor, a pulley and the steel rope 1000, a motor-side encoder 1200 is arranged on the motor, a joint-side encoder 1400 is arranged on the pulley, a motor-side band-type brake 1100 is arranged on the motor or a joint-side band-type brake 1300 is arranged on the pulley, and the method comprises the following steps:

acquiring joint encoder readingsAnd motor encoder reading->According to the reduction ratio->The two encoder readings are converted to the joint side or the motor side to obtain +.>And->The method comprises the steps of carrying out a first treatment on the surface of the Calculating absolute values of the difference values of the data measured by the joint-side encoder 1400 and the motor-side encoder 1200;

fitting a functional relationship between the tension of the steel rope 1000 and the difference values of the joint side encoder 1400 and the motor side encoder 1200 according to the tension calibration data of the steel rope 1000, wherein the tension calibration data of the steel rope 1000 is experimental data, and indicates the corresponding relationship between the tension of the steel rope 1000 and the absolute value of the difference values of the data measured by the joint side encoder 1400 and the motor side encoder 1200.

Calculation of rope 1000 tension from absolute value of difference between joint side encoder 1400 and motor side encoder 1200。

If the tension of the steel rope 1000 is greater than or equal to a set threshold valueJudging that the steel rope 1000 is not loosened, and running a robot control program; if the tension of the steel cord 1000 is smaller than a set threshold +.>And judging that the steel rope 1000 is loosened, controlling the robot to cut off power and starting the motor side band-type brake 1100 or the joint side band-type brake 1300.

In the prior art, each output shaft of the robot is not provided with an encoder, and the robot needs to be manually restored to an initial position when power is turned off and restarted. In the invention, referring to fig. 8, the robot controller converts the readings of the shaft encoders according to the reduction ratio of each shaft to compare the readings of the two encoders in real time, so as to detect whether the steel rope 1000 is loosened or broken. The motor band-type brake and the rotary joint band-type brake device also increase the running safety of the robot, and when the steel rope 1000 falls off or other serious faults occur, the band-type brake at the motor end or the joint end is started, so that the mechanical arm can be locked at the current position. The method comprises the following specific steps:after the robot is electrified and a program is started, judging whether the robot has a fault and is not cleared, if so, prompting an error, powering off and starting a band-type brake by the robot; if not, obtain joint encoder readingAnd motor encoder reading->According to the reduction ratio->The two encoder readings are converted to the joint side or the motor side to obtain +.>And->According to the fitted steel rope tensioning force calibration data and the absolute values of the two angle differences, the current tensioning force of the steel rope can be obtained>Judging whether the tension is smaller than a certain threshold, i.e. judging whether +.>If yes, the robot prompts errors, cuts off power and starts the band-type brake; if not, running the robot control program.

Referring to fig. 9, a joint driving unit of a robot (WAM, whole Arm Manipulator, full-arm dragable arm, rope-driven arm) is integrated with a motor driver, so that the space occupied by the internal wire harness of the robot is reduced. The controller is integrated at the base, need not outside electric cabinet. The communication mode between the controller and the driving unit is bus communication (CAN, etherCAT or other). A user can log in to the robot internal controller through a local area network remote SSH, can control the robot controller through a terminal with a robot control operating system (ROS, robot Operating System), and can control the robot by setting up a bypass internal controller and completely using an autonomous controller.

The invention provides a rope differential mechanism, which comprises an upper input motor 1601, an upper input pulley 1603, a third output pulley 1606, a lower input pulley 1604 and a lower input motor 1602, wherein the upper input motor 1601 is connected with the upper input pulley 1603 through a first transmission mechanism, the lower input pulley 1604 is connected with the lower input motor 1602 through a second transmission mechanism, the third output pulley 1606 is respectively coupled with the upper input pulley 1603 and the lower input pulley 1604 through a steel rope 1000, an output shaft or a connecting plate 1607 is arranged on the third output pulley 1606, and a fourth output shaft 1608 perpendicular to the axis of the third output pulley 1606 is arranged on the connecting plate 1607.

The first transmission mechanism and the second transmission mechanism are three-level steel rope 1000 transmission mechanisms, and comprise a first transmission shaft section and a second transmission shaft section;

in the first transmission mechanism, an upper input motor 1601, a first transmission shaft section, a second transmission shaft section and an upper input pulley 1603 are sequentially connected in a transmission way through a steel rope 1000;

The centerlines of the upper input pulley 1603 and the lower input pulley 1604 are collinear, and the third output pulley 1606 is perpendicular to the centerline of the upper input pulley 1603;

the upper input pulley 1603 and the third output pulley 1606 are provided with multiple steps for connecting the steel cable 1000;

the upper input pulley 1603 and the lower input pulley 1604 are arranged in parallel, a central shaft 1605 passing through the upper input pulley 1603 is arranged on the lower input pulley 1604, and a multi-stage step is arranged at the end of the central shaft 1605 and is coupled with the upper step of the third output pulley 1606 through a steel cable 1000.

The upper input motor 1601 and the lower input motor 1602 are provided with a motor side band-type brake 1100 and a motor side encoder 1200; the third output pulley 1606 and the fourth output shaft 1608 are provided with a joint-side band brake 1300 and a joint-side encoder 1400.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and improvements could be made by those skilled in the art without departing from the inventive concept, which falls within the scope of the present invention.

Claims

1. A rope-driven robot, characterized in that the robot has a plurality of joints to provide a plurality of degrees of freedom, at least one joint of the robot is driven by a rope-driven mechanism, the rope-driven mechanism comprises a motor, a steel rope and a pulley, the motor drives the pulley to rotate through the steel rope, and the pulley drives the joint of the robot to move; the motor is provided with a motor side encoder, and the pulley is provided with a joint side encoder;

the rope drive mechanism comprises a second rope differential mechanism, the second rope differential mechanism comprises an upper input motor, an upper input pulley, a third output pulley, a lower input pulley and a lower input motor, the upper input motor is connected with the upper input pulley through a first transmission mechanism, the lower input pulley is connected with the lower input motor through a second transmission mechanism, the third output pulley is respectively coupled with the upper input pulley and the lower input pulley through steel ropes, a connecting plate is arranged on the third output pulley and is used for being connected with a joint of the robot, and a fourth output shaft perpendicular to the axis of the third output pulley is arranged on the connecting plate;

the upper input pulley and the lower input pulley are arranged in parallel, a central shaft penetrating through the upper input pulley is arranged on the lower input pulley, and the tail end of the central shaft is provided with multiple steps and is coupled with the upper steps of the third output pulley through a steel rope;

and joint side encoders are arranged on the third output pulley, the upper input pulley and the lower input pulley.

2. The rope-driven robot according to claim 1, wherein in the rope-driven mechanism, a motor-side band-type brake is provided on a motor, or a joint-side band-type brake is provided on a pulley.

3. The rope drive robot of claim 2, wherein the robot has seven joints providing seven degrees of freedom, the robot comprising:

a base;

4. A rope driven robot according to claim 3, characterized in that the rope driven mechanism comprises a first rope driven mechanism, the first rope driven mechanism comprises a first motor and a first output pulley, the first motor and the first output pulley are driven by a steel rope, and a joint output shaft is arranged on the first output pulley and used for being connected with a certain joint of the robot;

5. The rope-driven robot of claim 4, wherein the first motor is provided with a motor-side encoder, and the first output pulley is provided with a joint-side encoder;

6. A rope driven robot according to claim 3, wherein the rope driven mechanism comprises a first rope differential mechanism, the first rope differential mechanism comprises a left input motor, a left input pulley, a second output pulley, a right input pulley and a right input motor, the left input motor is in transmission connection with the left input pulley through a steel rope, the right input pulley is in transmission connection with the right input motor through a steel rope, the second output pulley is respectively coupled with the left input pulley and the right input pulley through steel ropes, and a joint output shaft is arranged on the second output pulley and is used for being connected with a joint of the robot;

7. The rope-driven robot of claim 6, wherein the left input pulley, the second output pulley and the right input pulley are provided with multi-stage steps for connecting the steel ropes.

8. The rope-driven robot of claim 7, wherein motor-side encoders are provided on the left and right input motors, and joint-side encoders are provided on the second, left and right output pulleys;

9. The rope-driven robot according to claim 3, wherein,

10. The rope drive robot of claim 9 wherein the first and second drive mechanisms are three-stage steel rope drive mechanisms comprising a first drive shaft section and a second drive shaft section;

11. The rope-driven robot of claim 10, wherein the upper input pulley and the third output pulley are provided with multi-stage steps for connecting the steel ropes.

12. The rope-driven robot of claim 11, wherein motor-side encoders are provided on the upper and lower input motors;

13. The rope differential mechanism is characterized by comprising an upper input motor, an upper input pulley, a third output pulley, a lower input pulley and a lower input motor, wherein the upper input motor is connected with the upper input pulley through a first transmission mechanism, the lower input pulley is connected with the lower input motor through a second transmission mechanism, the third output pulley is respectively coupled with the upper input pulley and the lower input pulley through a steel rope, an output shaft or a connecting plate is arranged on the third output pulley, and a fourth output shaft perpendicular to the axis of the third output pulley is arranged on the connecting plate;

14. The rope differential of claim 13, wherein the first and second drive mechanisms are three-stage steel rope drive mechanisms comprising a first drive shaft section and a second drive shaft section;

15. A rope differential as defined in claim 14 wherein a plurality of steps are provided on said upper input pulley and third output pulley for connecting the steel ropes.

16. A rope differential as defined in claim 15 wherein motor side encoders are provided on said upper and lower input motors;

17. A rope-driven robot steel rope tension testing method according to any one of claims 1-12, wherein at least one joint of the robot is driven by a rope-driven mechanism, the rope-driven mechanism comprising a motor, a pulley and a steel rope, the motor being provided with a motor-side encoder, the pulley being provided with a joint-side encoder, the motor being provided with a motor-side band-type brake or the pulley being provided with a joint-side band-type brake, the method comprising: