CN105773647B - Rack-and-pinion becomes grip elasticity linkage adaptive robot finger apparatus - Google Patents

Abstract

A rack-type variable grip elastic linkage adaptive robot finger device belongs to the technical field of robotic hands, including motors, multiple finger segments, multiple joint shafts, transmission mechanisms, multiple transition shafts, multiple joint springs, and multiple pulleys , a plurality of driving levers, a plurality of dials, a plurality of gear parts, a rope wheel, and a tendon rope. The device of the present invention utilizes a motor, a transmission mechanism, a driven dial, a lever, a first gear, a second gear, a rack, a rope winding wheel, a tendon rope and a spring to comprehensively realize self-adaptive grasping and continuous locking of multiple joints Function. The device is used for grabbing objects, and can automatically adapt to the shape and size of the object; after grabbing the object, it can lock the joint or not; the grabbing process is fast and stable, and the joint is locked after grabbing to prevent the fingers from rebounding and becoming unstable. It can provide a large grasping force; the lockable joint angle is continuous; the device has a simple structure, small volume, light weight, easy control, and low manufacturing and maintenance costs.

Description

Rack type variable grip elastic linkage adaptive robot finger device

technical field

The invention belongs to the technical field of robot hands, and in particular relates to the structural design of a rack-type variable grip elastic linkage self-adaptive robot finger device.

Background technique

The robot hand is a very important operating part of the robot, and it is a hot research direction in the field of robot hands at present. Robotic hands can be divided into anthropomorphic hands and non-anthropomorphic hands according to whether they imitate human hands or not. Because the human hand has many degrees of freedom and is very flexible, it has great research and learning value in bionics, and the development of anthropomorphic robot hands similar to human hands has great application prospects. The current robot hands for anthropomorphic grasping are divided into industrial grippers, dexterous hands and underactuated hands.

On the one hand, the anthropomorphic robot hand needs to imitate certain movement functions of the human hand to grasp and carry objects of different shapes and sizes, which puts forward high requirements for the control accuracy of the robot hand; on the other hand, the anthropomorphic robot hand The structure is required to be as simple as possible, the size is appropriate, and the weight is small. These two aspects are contradictory. Existing industrial grippers have simple functions and limited scope of application. Existing dexterous hands have sufficient joints and actuators to perform various precise movements, but they use many actuators, complex sensing and control, and are expensive. The under-actuated hand solves this contradiction better due to the adaptive grasping function. The adaptive underactuated robot hand is small in size and light in weight. It can change the grasping angle to automatically adapt to the shape of the object in the process of grasping the object. The control is simple and the grasping is relatively stable.

In an existing manipulator device for adaptively grasping objects (invention patent US2006129248A1), the finger part mainly includes a base, four finger segments, three springs and a tendon rope. When grabbing an object, first pull the tendon cord to straighten the fingers, then relax the tendon cord, relying on the elasticity of the spring itself to make the fingers bend and envelop the object. Since each joint has a spring, the finger can be bent according to the corresponding angle according to the shape of the object in the process of grabbing the object, which has good adaptability.

The disadvantages of this device are:

1) There is a big contradiction between the grabbing force of the spring part of the device being as large as possible and the pulling force of the tendon cord used to straighten the fingers being as small as possible. In order to ensure a large grasping force, the stiffness coefficient of the required spring is relatively large, resulting in a large pulling force required to pull the tendon rope to straighten the finger; if the pulling force required to straighten the finger is relatively small, use a weaker spring, the gripping force is too low.

2) It is difficult for the device to provide a wider range of gripping force. The device adopts a fixed spring, and the grasping force provided is limited to a fixed small range; the device mainly relies on the grasping force provided by the spring in the process of grasping objects. If the spring is relatively weak, it cannot be used The strength of the connected arm will cause grasping failure when picking up heavy objects. For example, when picking up a very heavy suitcase, arm strength is generally used for extraction, but the fingers must have sufficient strength to ensure a curved configuration.

3) A spring with an excessively large stiffness coefficient may cause the fingers to quickly collide with the object when grasping the object, thereby causing the instability of the object to be squeezed away.

4) When the device is used in a vibrating environment, there is a possibility of grasping failure.

There is an existing self-locking pneumatic underactuated robot finger device, which has an adaptive grasping function, uses a ratchet pawl to realize self-locking during the grasping process, and uses a motor to pull the pawl to realize unlocking.

The disadvantages of this device are:

1) The device requires a pushing force to achieve adaptive bending. This driving force comes from the relative motion between the finger and the object: the object squeezes the slider on the finger, and the pneumatic transmission is used to push the next finger segment to bend.

2) The lockable joint angles of the device are discontinuous. Because the teeth of the ratchet have a certain pitch, the locking is discontinuous; if the pitch is designed to be large, the locking accuracy will be reduced, and if the pitch is designed to be small, the height of the teeth will be reduced, affecting the locking effect.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and propose a rack-type variable grip elastic linkage adaptive robot finger device, which is used for grabbing objects and can automatically adapt to the shape and size of the object; After the object is picked up, the joint can be locked or not locked; the joint can be locked after grasping, which can provide a large grasping force and prevent the fingers from rebounding and unstable; the lockable joint angle is continuous; the device has a simple structure and is light in weight. Light and easy to control.

The present invention adopts following technical scheme:

The present invention provides a rack-type variable grip elastic linkage self-adaptive robotic finger device, comprising a base, a first finger section, a second finger section, a first joint shaft, a second joint shaft, a motor, and a first transmission mechanism , a transition shaft, a rope winding wheel, a tendon rope, a first pulley, a second pulley, a first spring and a second spring; the motor is fixedly mounted on the base, and the output shaft of the motor and the first transmission mechanism connected to the input end of the first transmission mechanism, the output end of the first transmission mechanism is connected to the transition shaft, the transition shaft is sleeved in the base, the rope winding wheel is fixed on the transition shaft; one end of the tendon rope is fixed to On the outer edge of the rope winding wheel, the other end of the tendon rope is affixed to the second finger section; the tendon rope goes around the first pulley and the second pulley, and the tendon rope passes through the first finger section and the second finger section; The first joint shaft is sleeved in the base, the second joint shaft is sleeved in the first finger segment; the first finger segment is sleeved on the first joint shaft, and the second finger segment is sleeved connected to the second joint shaft; the first pulley is sleeved on the first joint shaft, and the second pulley is sleeved on the second joint shaft; the two ends of the first spring are respectively connected to the base and The first finger section; the two ends of the second spring member are respectively connected to the first finger section and the second finger section; the first joint axis and the second joint axis are parallel to each other; it is characterized in that: the device also includes an active dial Plate, driven dial, second transmission mechanism, first gear, rack, second gear, first shift lever, second shift lever, third spring member and fourth spring member; The first bump is connected, and the second bump is fixed on the driven dial; the driving dial is sleeved on the transition shaft, and the driving dial is fixedly connected to the rope wheel; the driven dial It is movably socketed on the transition shaft, the first protrusion contacts and pushes the second protrusion during the motion of grasping the object, and the first protrusion leaves and withdraws to the second protrusion during the motion of straightening the finger. The driving force of the bump; the input end of the second transmission mechanism is connected with the driven dial; the output end of the second transmission mechanism is connected with the first gear; the first gear is sleeved on the first joint shaft , the second gear is sleeved on the second joint shaft, the first gear is connected to the second gear through a rack, and the rack is respectively meshed with the first gear and the second gear; the third The two ends of the spring member are respectively connected to the first gear and the first driving rod, and the two ends of the fourth spring member are respectively connected to the second gear and the second driving rod; the first driving rod is sleeved on the first joint shaft , the second lever is sleeved on the second joint shaft; the first lever contacts and pushes the first finger segment during rotation; the second lever contacts and pushes the second finger segment during rotation part.

Compared with the prior art, the present invention has the following advantages and outstanding effects:

The device of the present invention utilizes the motor, the transmission mechanism, the driven dial, the lever, the first gear, the second gear, the rack, the rope winding wheel, the tendon rope and the spring to comprehensively realize self-adaptive grasping and continuous locking of multiple joints function. The device is used for grabbing objects, which can automatically adapt to the shape and size of the objects, and has strong adaptability; after grabbing objects, it can lock the joints or not, especially for objects of different materials and weights. The grasping process is fast and stable, and the joints are locked after grasping. On the one hand, it prevents the fingers from rebounding and becoming unstable, so that objects will not collide with or squeeze objects when grasping objects; on the other hand, it can provide greater grasping force and lock The final finger device can be approximately regarded as a rigid body, and its bearing capacity can better match the arm device connected to it, and implement the extraction of relatively heavy objects (such as luggage); the lockable joint angle is continuous; the The device has the advantages of simple structure, small size, light weight, easy control, and low manufacturing and maintenance costs.

Description of drawings

Fig. 1 is a front sectional view of an embodiment of the rack-type variable grip elastic linkage adaptive robot finger device provided by the present invention.

Fig. 2 is a front appearance view of the embodiment shown in Fig. 1 .

Fig. 3 is a reverse appearance view of the embodiment shown in Fig. 1 .

Fig. 4 is an external view of the left side of the embodiment shown in Fig. 1 .

Fig. 5 is an external view of the right side of the embodiment shown in Fig. 1 .

6 to 9 are schematic diagrams of possible implementations of the kinematic relationship between the rope winding wheel and the driven dial.

Fig. 10 to Fig. 12 are appearance diagrams of adaptively grasping objects in the illustrated embodiment.

Fig. 13 to Fig. 15 are appearance diagrams of adaptively grasping large-sized and irregularly shaped objects according to the embodiment shown.

Fig. 16 to Fig. 19 are schematic diagrams of active locking and self-adaptive grabbing of heavy objects in the illustrated embodiment (the heavy object in the illustration of this embodiment is a heavy suitcase).

In Figures 1 to 19:

1-base, 11-first finger segment, 12-second finger segment,

21-first joint axis, 22-second joint axis,

3-motor, 31-reducer, 32-first bevel gear, 33-second bevel gear,

4- transition shaft, 41- rope wheel, 42- tendon rope,

431-the first bump, 441-the second bump, 45-driving pulley,

46-driven pulley, 47-drive belt, 51-first pulley, 52-second pulley,

61-the first spring part, 62-the second spring part, 63-the third spring part, 64-the fourth spring part,

71-first gear, 72-second gear, 73-rack,

81-the first lever, 82-the second lever,

9—object, 91—support surface, 92—suitcase, 921—grab handle.

Detailed ways

The specific structure, working principle and working process of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

An embodiment of the rack type variable grip elastic linkage adaptive robot finger device designed by the present invention, as shown in Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5, a rack type variable grip The elastic linkage adaptive robot finger device includes a base 1, a first finger segment 11, a second finger segment 12, a first joint shaft 21, a second joint shaft 22, a motor 3, a first transmission mechanism, a transition shaft 4, and a Sheave 41, tendon rope 422, the first pulley 51, the second pulley 52, the first spring 61 and the second spring 62; the motor 3 is fixedly installed on the base 1, the output shaft of the motor 3 and The input end of the first transmission mechanism is connected, the output end of the first transmission mechanism is connected with the transition shaft 4, the transition shaft 4 is sleeved in the base 1, and the rope winding wheel 41 is sleeved on the transition shaft 4 One end of the tendon rope 422 is affixed to the outer edge of the rope winding wheel 41, and the other end of the tendon rope 422 is affixed to the second finger segment 12; the tendon rope 422 is bypassed by the first pulley 51 and the second pulley 52, the tendon rope passes through the first finger segment 11 and the second finger segment 12; the first joint shaft 21 is sleeved in the base 1, and the second joint shaft 22 is sleeved in the first finger segment 11; The first finger segment 11 is sleeved on the first joint shaft 21, the second finger segment 12 is sleeved on the second joint shaft 22; the first pulley 51 is sleeved on the first joint shaft 21, The second pulley 52 is sleeved on the second joint shaft 22; the two ends of the first spring member 61 are respectively connected to the base 1 and the first finger section 11; the two ends of the second spring member 62 are respectively connected to The first finger segment 11 and the second finger segment 12; the first joint axis 21 and the second joint axis 22 are parallel to each other.

The device also includes a driving dial, a driven dial, a second transmission mechanism, a first gear 71, a second gear 72, a rack 73, a first driving lever 81, a second driving lever 82, a third spring member 63 and The fourth spring member 64; the first protrusion 431 is fixedly connected to the driving dial, and the second protrusion 441 is fixed to the driven dial; the driving dial is sleeved on the transition shaft 4, The driving dial is fixedly connected to the rope winding wheel 41; the driven dial is movably sleeved on the transition shaft 4, and the first bump 431 contacts and pushes the second bump 441 during the movement of grabbing objects, The first projection 431 leaves and withdraws the impetus to the second projection 441 during the motion of straightening the finger; the input end of the second transmission mechanism is connected with the driven dial; the second transmission mechanism The output end is connected with the first gear 71; the first gear 71 is sleeved on the first joint shaft 21, the second gear 72 is sleeved on the second joint shaft 22, the first gear 71 and the first joint shaft The two gears 72 are connected by a rack 73, and the racks 73 form a gear engagement with the first gear 71 and the second gear 72 respectively; the two ends of the third spring member 63 are respectively connected to the first gear 71 and the first driving rod 81, the two ends of the fourth spring member 64 are respectively connected to the second gear 72 and the second driving rod 82; the first driving rod 81 is sleeved on the first joint shaft 21, and the second driving rod 82 is sleeved Connected to the second joint shaft 22; the first driving rod 81 contacts and pushes the first finger segment 11 during rotation; the second driving rod 82 contacts and pushes the second finger segment 12 during rotation.

In this embodiment, the first transmission mechanism includes a reducer 31 , a first bevel gear 32 and a second bevel gear 33 . Wherein the output shaft of the motor 3 is connected with the input shaft of the speed reducer 31, the first bevel gear 32 is sleeved on the output shaft of the speed reducer 31, the first bevel gear 32 meshes with the second bevel gear 33, and the The second bevel gear 33 is sleeved on the transition shaft 4 . .

In this embodiment, the second transmission mechanism adopts a pulley transmission mechanism, including a driving pulley 45 , a driven pulley 46 and a transmission belt 47 . The driving pulley 45 is sleeved on the transition shaft 4, the driving pulley 45 is fixedly connected with the driven dial, the driving pulley 45 is connected to the driven pulley 46 through a transmission belt 47, and the driving pulley 45, The driven pulley 46 and the transmission belt 47 form a pulley transmission relationship. The driven pulley 46 is sleeved on the first joint shaft 21 , and the driven pulley 46 is fixedly connected to the first gear 71 .

In this embodiment, the driven dial is rotatably arranged in the first finger section 1, the axial centerline coincides with the axial centerline of the rope winding wheel 41, and the driven dial affixed to the driven dial The second protrusion 441 of the disk and the first protrusion 431 of the rope winding wheel 41 affixed to the rope winding wheel 41 are arranged on one side between the driven dial and the rope winding wheel 41 .

6 to 9 mainly express several implementations of the rope winding wheel 41 and the driven dial. Wherein position E and position F are respectively the initial contact positions of the first protrusion 431 of the rope winding wheel affixed on the rope winding wheel 41 and the second protrusion 441 of the driven dial affixed on the driven dial; When the first lug 431 of the wheel moves from the position E to the position E1, it is the process of tightening the tendon rope 42. The tendon rope 42 at the position E1 is completely tightened. The position F1 of the second projection 441 is still at position F; when the first projection 431 of the rope winding wheel reversely moves from position E1 to E, the tendon rope 42 is fully tensioned to a fully relaxed state, and the first projection of the rope winding wheel 431 and the second protrusion 441 of the driven dial come into contact. Then during the movement from position E to position E2, the rope winding wheel 41 pushes the second projection 441 of the driven dial through the first protrusion 431 of the rope winding wheel and drives the driven dial to move, and the motion is transmitted through the second transmission mechanism For the first gear 71, the second gear 72 and other components, the active locking of the first finger segment 11 and the second finger segment 12 is finally realized. During this process, the second protrusion 441 of the driven dial moves from position F1 to F2, and position F2 is locked.

The rope winding wheel 41 and the driven dial of this embodiment mainly adopt the implementation shown in FIG. 9 .

The working principle of the present embodiment is described as follows:

Figures 10 to 12, Figures 13 to 15, and Figures 16 to 19 are schematic diagrams of the relative positions of the fingers during the grasping process under different grasping conditions.

First, the motor 3 is started, and the rope wheel 41 is driven to rotate through the reducer 31, the first bevel gear 32, the second bevel gear 33 and the transition shaft 4, so that the tendon rope 42 is tightened, and the fingers are stretched from the bent state to fully stretched. Straight state, ready to grasp the object, now the schematic diagram of the appearance of the finger is shown in Figure 10, and the schematic diagram of the main structure of the finger is shown in Figure 12; Relax, the elastic force of the first spring member 61 and the second spring member 62 makes the fingers gradually bend. In the case of not grabbing an object, when the tendon rope 42 is completely relaxed, the fingers are completely bent into a clenched state; in the case of grabbing an object, the fingers bend to contact and adaptively envelop the object, and now the motor 3 then rotates to the tendon The rope 42 is fully relaxed, and the appearance or structure of the fingers during this process is shown in Figures 10 to 12, 13 to 15 and 16 to 19. Since the deformation of the first spring member 61 and the second spring member 62 can be continuous, the angle α between the first lever action surface and the contact end surface of the second finger section after the finger adaptive envelope grips the object is The change of the included angle β between the active surface of the driving lever and the contact end surface of the third finger segment is also continuous. That is, the process of fingers adaptively grasping objects is continuous.

Afterwards, the motor 3 continues to rotate, and the rope winding wheel 41 contacts the second projection 441 of the driven dial through the first protrusion 431 of the rope winding wheel and drives the driven dial to rotate in the same direction, and the driven dial is driven by the second transmission mechanism. The driving pulley 45 rotates. The driving pulley 45 and the driven pulley 46 are connected by a transmission belt 47 to realize synchronous rotation. One end of the second spring member 62 is connected with the driving pulley 45 , and the other end is connected with the first driving lever 81 . One end of the fourth spring member 64 is connected with the driven pulley 46 , and the other end is connected with the second driving lever 82 .

First, the synchronous transmission belt 47 drives the driving pulley 45 and the driven pulley 46 to rotate synchronously. Under the limitation of the driving lever, the driving pulley 45 or the driven pulley 46 connected by the linkage spring will be linked (that is, rotate synchronously); when the first driving lever 81 contacts and is pressed on the first finger segment 11 and the second In the process that the second driving lever 82 has not yet contacted the second finger segment 12, the first finger segment 11 has been locked, and the second finger segment has not yet been locked. During the process, the first gear 71 will continue to rotate and drive the driven pulley through the transmission belt 47 46 rotates synchronously with the second driving lever 82. During this process, the deformation of the second spring member 62 is constantly increasing, and the initial small deformation required when the fourth spring member 64 still maintains linkage is ignored in the figure; The second finger segment 12, the locking of the second finger segment 12 is completed. During this process, the deformation of the second spring member 62 continues to increase, and the locking force of the finger segment also increases continuously, which realizes the stable grasping of the fingers.

The first gear 71 and the second gear 72 respectively drive the first driving lever 81 and the second driving lever 82 to press against the first finger segment 11 and the second finger segment 12 to stop rotating so as to complete the locking of the finger segment. The deformation of the second spring member 62 and the fourth spring member 64 makes the first driving rod 81 and the first gear 71, the second driving rod 82 and the second gear 72 produce a large elastic force, so that the first driving rod 81. The second driving lever 82 is reliably pressed on the first finger segment 11 and the second finger segment 12 respectively, and it is difficult for all finger segments to rotate or rebound, thus forming an effect similar to locking finger joints.

The working process of this embodiment is shown in Figure 10 to Figure 19, which expresses the situation of grabbing different shapes, sizes and weights of this embodiment, specifically described as follows:

The first situation is shown in Fig. 10, Fig. 11 and Fig. 12, which are schematic diagrams of the appearance of fingers during the process of grasping objects of smaller size. First, pull the tendon rope 42 to make the finger straight, then move the finger to make it close to the object; loosen the tendon rope 42, the finger gradually bends, the base 1 and the first finger section 11 successively contact the object, and then the first spring member 61 no longer Reply, the first joint axis 21 stops rotating; when the second finger segment 12 fully touches the object, the whole finger device has just completed the process of grasping the object adaptively. Due to the small size and low mass of the object, a stable and reliable gripping task can now be carried out without using the locking function.

The second case, as shown in Fig. 13, Fig. 14 and Fig. 15, is the process of grabbing irregularly shaped objects. The grasping process in this case is basically similar to the first case, and the object is relatively light and small, and the locking function can be used or not, and both options can achieve better results.

The third kind of situation is as shown in Figure 16, Figure 17, Figure 18 and Figure 19, is the process of grabbing heavier objects (in the present embodiment, adopting a heavier luggage case 33 with grabbing handle 331) and moving. The crawling process is basically similar to the first category, but in this case the locking function needs to be used. After the finger has enveloped the object, then loosen the tendon cord 42; when the tendon cord 42 is completely relaxed, the driven dial can then be driven to rotate in the same direction, and finally the first driving lever 81 and the second driving lever 82 are used to actively lock the two dials. Refers to segment. Through the two processes of adaptive grasping and multi-joint active locking, the fingers can grasp heavy objects, and the grasping process is fast and stable.

The device of the present invention utilizes a motor, a transmission mechanism, a driven dial, a lever, a first gear, a second gear, a rack, a rope winding wheel, a tendon rope and a spring to comprehensively realize self-adaptive grasping and continuous locking of multiple joints Function. The device is used for grabbing objects, which can automatically adapt to the shape and size of the objects, and has strong adaptability; after grabbing objects, it can lock the joints or not, especially for objects of different materials and weights. The grasping process is fast and stable, and the joints are locked after grasping. On the one hand, it prevents the fingers from rebounding and becoming unstable, so that objects will not collide with or squeeze objects when grasping objects; on the other hand, it can provide greater grasping force and lock The final finger device can be approximately regarded as a rigid body, and its bearing capacity can better match the arm device connected to it, and implement the extraction of relatively heavy objects (such as luggage); the lockable joint angle is continuous; the The device has the advantages of simple structure, small size, light weight, easy control, and low manufacturing and maintenance costs.

Claims (1)

1. a kind of rack-and-pinion becomes grip elasticity linkage adaptive robot finger apparatus, refer to including pedestal, the first segment, second Section, the first joint shaft, second joint axis, motor, the first transmission mechanism, transition axis, rope-winding wheel, tendon rope, first pulley, second are slided Wheel, the first spring part and the second spring part；The motor is fixedly mounted on pedestal, the output shaft of the motor and the first transmission mechanism Input terminal be connected, the output terminal of first transmission mechanism is connected with transition axis, and the transition axis is set in pedestal, described Rope-winding wheel is fixed on transition axis；One end of the tendon rope is fixed in the outer rim of rope-winding wheel, and the other end of tendon rope and second refers to Section is affixed；The tendon rope bypasses first pulley and second pulley, and tendon rope passes through the first segment and the second segment；First joint Axle sleeve is located in pedestal, and the second joint axle sleeve is located in the first segment；First segment is socketed on the first joint shaft, Second segment is socketed on second joint axis；The first pulley is socketed on the first joint shaft, the second pulley set It is connected on second joint axis；The both ends of the first spring part connect pedestal and the first segment respectively；The both ends of the second spring part The first segment and the second segment are connected respectively；First joint shaft, second joint axis are mutually parallel；It is characterized in that：The dress Put further include active driver plate, driven driver plate, the second transmission mechanism, first gear, rack, second gear, the first driving lever, second group Bar, third spring part and the 4th spring part；The first convex block is connected on the active driver plate, it is convex to be connected with second on the driven driver plate Block；The active driver plate is socketed on transition axis, and active driver plate and rope-winding wheel are affixed；The driven driver plate is actively socketed on transition On axis, first convex block contacts in the motion process of crawl object and pushes the second convex block, and first convex block is stretching It is left in the motion process of finger and recalls the motive force to the second convex block；The input terminal of second transmission mechanism with driven group Disk is connected；The output terminal of second transmission mechanism is connected with first gear；The first gear is socketed on the first joint shaft, The second gear is socketed on second joint axis, and the first gear is connected with second gear by rack, the rack point Do not form gear with first gear, second gear and engage；The both ends of the third spring part connect first gear and first group respectively Bar, the both ends of the 4th spring part connect second gear and the second driving lever respectively；First driving lever is socketed in the first joint shaft On, second driving lever is socketed on second joint axis；First driving lever contacts in rotation process and pushes the first segment； Second driving lever contacts in rotation process and pushes the second segment.