CN101739129B - Four freedom degrees flexible cable driven man-machine interaction device capable of feeding back grasping force - Google Patents

Abstract

The invention discloses a four-degree-of-freedom flexible cable-driven human-computer interaction device with grasping force feedback, which includes a static platform, four rigid flexible cables, four flexible cable drive mechanisms, index finger cots, thumb cots, an elastic flexible search. The four rigid flexible cables are divided into two groups of two, and each group of rigid flexible cables is tied to a point on the thumb and forefinger fingertips respectively, and the two fingertips are connected by elastic flexible cables. The binding points of the elastic and rigid cables on the thumb and index finger cuffs are collinear. The resultant force formed by the tension of the rigid cable and the elastic force of the elastic cable can provide force feedback with four degrees of freedom to the operator. The invention adopts a parallel structure, which has a large working space and large output force and moment; it is driven by flexible cables, the inertia of the transmission structure is small, the interference between flexible cables is not easy to occur, and the operation is flexible; the number of flexible cables used is small, the structure is simple, and no need to change the device The structure can simultaneously simulate the plane three-degree-of-freedom force sense and one-degree-of-freedom grasping feeling; it has strong versatility and wide application fields.

Description

A four-degree-of-freedom cable-driven human-computer interaction device with gripping force feedback

technical field

The invention relates to the field of human-computer interaction, in particular to a four-degree-of-freedom cable-driven human-computer interaction device with grasping force feedback. The device can not only simulate the three-degree-of-freedom force and moment generated when virtual objects moving on a plane collide with each other, but also can feedback the one-dimensional grasping force of two fingers when grasping the object.

Background technique

The force-sense human-computer interaction device is a device that provides the operator with a force-sense interaction experience. Force sensation is part of the human body's sense of touch. This feeling is mainly perceived by the sensory organs in the deep layers of human bones, joints and muscles. When people interact with the virtual reality environment, the operator feels the force when interacting with the virtual object, the shape and stiffness of the object, and even the movement of the object through the force-sense interaction device, and experiences the sense of force as operating a real object. perceived effect. Force-sense interactive devices have been widely used in many fields such as medical treatment, industry, teaching and entertainment, and have strong development potential.

Divided by installation method, the types of force-sensing interaction devices include two types fixed on the operator's arm and fixed on the workbench, which are suitable for different applications. The former mainly includes data arms and data gloves. This type of equipment is characterized by being able to track the multi-degree-of-freedom movement of the operator's arm or fingers, but it generally has the disadvantages of large size, heavy weight, and poor fidelity of force perception. Where realistic perception of interaction forces is required, it is generally used in master-slave operations of robotic arms or robotic dexterous hands.

Traditional force-sense interaction devices often can only simulate the force and force distance of one or more degrees of freedom generated when a moving object collides with other virtual objects, but cannot simultaneously simulate the grasping of the moving object when the operator grasps it. force.

Contents of the invention

In order to solve the above problems, the present invention provides a four-degree-of-freedom cable-driven human-computer interaction device capable of simultaneously feeding back three-degree-of-freedom force sense and one-degree-of-freedom grasping sensation. The device can not only simulate the three-degree-of-freedom force and moment generated when virtual objects moving on a plane collide with each other, but also can feedback the one-dimensional grasping force of two fingers when grasping the object.

The present invention is a four-degree-of-freedom flexible cable-driven human-computer interaction device with grasping force feedback, comprising a static platform, a rigid flexible cable, a flexible cable driving mechanism, an index finger cuff, a thumb cuff, and an elastic flexible cable.

The static platform is symmetrically provided with four flexible cable driving mechanisms, each flexible cable driving mechanism is connected to the fixed end of a rigid flexible cable, the free ends of the two rigid flexible cables on the same side of the static platform are connected to the index finger finger cot, and the other two A free end of a rigid cable is connected to the thumb cover, and an elastic cable is connected between the index finger cover and the thumb cover.

The static platform includes a support plate, a calibration frame, and a guide plate; the calibration frame is bonded and fixed on the support plate; a rectangular groove is opened in the support plate; four guide plates are evenly fixed and bonded to the four corners of the calibration frame; A calibration groove A and a calibration groove B are arranged side by side on the calibration frame.

The flexible cable drive mechanism includes a motor, a motor base, a winch, and an encoder; the end of the motor is connected to an encoder; the motor shaft of the motor passes through the motor mounting hole on the motor base and is fixed on the motor base, and the motor shaft is inserted into the shaft hole of the winch Among them, the winch is fixed on the motor shaft with fastening screws; the bearing end of the winch passes through the bearing, and the bearing is installed in the bearing installation hole of the motor base; the fixed end of the rigid cable is fixed on the winch, and wraps around the thread on the winch The slots are wound on the winch in sequence; the installed motor base is installed on the base and fastened with screws.

The index finger cot includes an outer coat of the index finger cot and an inner sheath of the index finger cot; the thumb cot includes an outer coat of the thumb cot and an inner sheath of the thumb cot; In the cable driving mechanism, the free end of the rigid flexible cable wound on the winch passes through the guide hole on the hole guide plate and is connected with the index finger cover or the thumb cover.

The free end of the rigid flexible cable on the same side passes through the outer wire hole A on the index finger sleeve jacket, and is threaded into the inner side of the index finger finger sleeve jacket, and then tied and fixed; the free end of the rigid flexible cable on the other side passes through the outer wire on the thumb finger sleeve jacket Hole B is threaded into the inner side of the thumb sleeve and then tied and fixed; the two ends of the elastic cable are respectively inserted into the inner wire hole A on the index finger sleeve and the inner wire hole B on the thumb sleeve, and are placed on the inner side of the index finger sleeve. The inner side of the thumb sleeve is tied and fixed; the inner sleeve of the index finger sleeve is embedded in the outer sleeve of the index finger sleeve, and is fixed by bonding; the inner sleeve of the thumb sleeve is embedded in the outer sleeve of the thumb sleeve, and is fixed by bonding.

The flexible cable drive mechanism is attached to the support plate, and the fastening bolts pass through the base installation holes on the base of the flexible cable drive mechanism and are fixed on the four corners of the support plate; the anchor bolts are installed on the anchor installation holes of the base .

The present invention is a four-degree-of-freedom flexible cable-driven human-computer interaction device with gripping force feedback, which has the following advantages:

1. Adopt parallel structure, large working space, large output force and moment;

2. Driven by flexible cables, the inertia of the transmission structure is small, the interference between flexible cables is not easy to occur, and the operation is flexible;

3. The number of flexible cables used is small and the structure is simple. Only five flexible cables can be used to complete the simulation of plane three-degree-of-freedom force sense and one-degree-of-freedom grasping force;

4. Simultaneously simulate plane three-degree-of-freedom force sense and one-degree-of-freedom grip feeling without changing the structure of the device;

5. Strong versatility and wide application fields.

Description of drawings

Fig. 1 is the overall structural diagram of the human-computer interaction device of the present invention;

Fig. 2 is an assembly diagram of the static platform in the human-computer interaction device of the present invention;

Fig. 3 is an assembly diagram of the cable driving mechanism in the human-computer interaction device of the present invention;

Fig. 4 is a connection structure diagram of the thumb cot, index finger cot, rigid cable and elastic cable in the human-computer interaction device of the present invention;

Fig. 5 is an assembly drawing of the flexible cable driving mechanism and the static platform in the human-computer interaction device of the present invention;

Fig. 6 is a schematic diagram of the mechanism of the human-computer interaction device of the present invention;

Fig. 7 is a schematic diagram of the calibration of the human-computer interaction device of the present invention.

In the picture:

1-static platform 2-rigid flexible cable 3-flexible cable drive mechanism 4-index finger cot

5-thumb finger sleeve 6-elastic cable 7-fastening bolt 8-anchor bolt

101-Support plate 102-Calibration frame 103-Guide plate 104-Rectangular groove

105-Calibration groove A 106-Guide hole 107-Calibration groove B 301-Motor

302-motor seat 303-winch 304-bearing 305-encoder

306-Motor shaft 307-Motor mounting hole 308-Bearing end 309-Bearing mounting hole

310-Base 311-Base mounting hole 312-Foot mounting hole 313-Axis hole

401-Inner index finger cover 402-Inner index finger cover 403-Outer wire hole A 404-Inner wire hole A

501-thumb finger sleeve jacket 502-thumb finger sleeve inner sleeve 503-outer wire hole B 504-inner wire hole B

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

The present invention is a four-degree-of-freedom flexible cable-driven human-computer interaction device with grasping force feedback, as shown in Figure 1, including a static platform 1, four rigid flexible cables 2, four flexible cable drive mechanisms 3, and index finger finger cot 4 1. Thumb finger sleeve 5. An elastic cable 6.

Four flexible cable drive mechanisms 3 are arranged symmetrically on the static platform 1, and each flexible cable drive mechanism 3 is connected to the fixed end of a rigid flexible cable 2, and the free ends of the two rigid flexible cables 2 on the same side of the static platform 1 are connected to the index finger. cover 4, the free ends of the other two rigid cables 2 are connected to the thumb cover 5, and an elastic cable 6 is connected between the index finger cover 4 and the thumb cover 5.

As shown in FIG. 2 , the static platform 1 is a rectangular structure, including a support plate 101 , a calibration frame 102 , and four hole guide plates 103 . The calibration frame 102 is glued and fixed on the support plate 101 , and the distances from each edge on the calibration frame 102 to each edge on the support plate 101 are equal. A rectangular groove 104 is formed inside the support plate 101 , and the size of the rectangular groove is the same as that of the inner frame of the calibration frame 102 . Four hole guide plates 103 are evenly fixed and bonded to the four corners of the calibration frame 102. There are guide holes 106 on the hole guide plate 103. The guide holes 106 are in the same surface, pointing to the center of the calibration frame 102, and are used for rigid cables. 2 through, positioning. Calibration groove A105 and calibration groove B107 are arranged side by side on the calibration frame 102. The calibration groove A105 and the calibration groove B107 are semicircular in structure, and their diameters are respectively equal to those of the index finger cover 401 and the thumb cover 501. The depth of the rectangular groove 104 is set after the fingers wear the index finger cot 4 and the thumb cot 5, and the rigid cable 2 and the elastic cable 6 work in the same plane. The movement range of the finger cot is limited by the calibration frame 102 and the rectangular groove 104 together.

As shown in FIG. 3 , the cable driving mechanism 3 includes a motor 301 , a motor base 302 , a winch 303 and an encoder 305 . An encoder 305 is installed at the end of the motor, which is used to measure the angle rotated by the motor shaft 306 and convert it into the change of the length of the rigid cable 2 . The motor shaft 306 of motor 301 passes the motor installation hole 307 on the motor base 302 and is fixed on the motor base 302, and the motor shaft 306 is inserted in the shaft hole 313 of the capstan 303, and the capstan 303 is fixed on the motor shaft 306 with screws, and is connected with the motor Shaft 306 rotates together. The bearing end 308 of the winch 303 passes through the bearing 304 , and the bearing 304 is installed in the bearing installation hole 309 of the motor base 302 . The fixed end of the rigid cable 2 is fixed on the capstan 303, and is wound on the capstan 303 sequentially around the thread groove on the capstan 303, and the other end of the rigid cable 2 is a free end, which is used to connect the index finger cot 4 or the thumb finger cot5. The installed motor base 302 is installed on the base 310 and fastened on the static platform 1 by bolts. The rigid flexible cable 2 is a flexible cable that does not elastically deform or generate elastic force under the action of tension, and is a steel wire rope in this embodiment.

As shown in FIG. 4 , the index finger cot 4 includes an outer index finger cot 401 and an inner index finger cot 402 ; the thumb cot 5 includes a thumb cot outer 501 and an inner thumb cot 502 . The middle part of the thumb cover 5 and the index finger cover 4 is hollow, and the thumb cover 5 and the index finger cover 4 can be placed on the distal joints of the fingers, so that the fingers extend out of the finger cover and contact the surface of the rectangular groove 104 on the support plate 101 . In the cable driving mechanism 3 , the free end of the rigid cable 2 wound on the winch 303 passes through the guide hole 106 on the hole guide plate 103 and is connected with the index finger cover 401 or the thumb cover 501 .

Two rigid flexible cables 2 free ends of the same side pass through the outer thread hole A403 on the index finger finger cover overcoat 401 and then end and fix in the index finger finger cover cover 401 inner side. After the free ends of the two rigid cables 2 on the other side pass through the outer line hole B503 on the thumb cover overcoat 501, they are tied and fixed in the thumb cover overcoat 501 inner side. The two ends of the elastic flexible cable 6 are respectively inserted into the inner thread hole A404 on the index finger cover coat 401 and the inner thread hole B504 on the thumb finger cover cover 501, and then end and fix on the inner side of the index finger finger cover cover 401 and the thumb cover cover 501 inside . The axes of the outer wire hole A403 on the index finger finger sleeve cover 401 and the outer wire hole B503 on the thumb finger sleeve cover 501 are collinear with the elastic cable 6 . The axes of the outer line hole A403 on the index finger cover coat 401 and the outer line hole B503 on the thumb cover cover 501 are co-linear with the inner line hole A404 on the index finger cover cover 401 and the inner line hole B504 on the thumb cover cover 501 respectively. The thumb cot inner cover 502 is embedded in the thumb cot outer cover 501 and fixed by bonding. The inner sleeve 402 of the index finger sleeve is embedded in the outer sleeve 401 of the index finger sleeve, and is fixed by bonding. Thumb cover 501 and index finger cover 401 are annular and made of rigid material. The diameters of index finger cover 401 and thumb cover 501 are respectively equal to the calibration groove A105 and the calibration groove B107. The inner sleeve 502 of the thumb sleeve and the inner sleeve 402 of the index finger sleeve are made of elastic material, and are used to fit the surface of the finger. The elastic flexible cable 6 is a flexible cable that elastically deforms only under the action of tension to generate elastic force, and is a rubber band or a tension spring in this embodiment. Described thumb fingertip 5 and forefinger fingertip 4 also can be other two finger fingertips. The finger cot can also be directly transformed into the clamping end of the clamping tool to expand the application environment of the device simulation.

As shown in Figure 5, the flexible cable driving mechanism 3 is attached to the supporting plate 101, and is fixed on the four corners of the supporting plate 101 by fastening bolts 7 passing through the base mounting holes 311 on the base 310 in the flexible cable driving mechanism 3 . The anchor bolts 8 are installed on the anchor mounting holes 312 of the base 310 to support the whole device. Threads are processed in the anchor mounting holes 312, and the height of the device can be adjusted by adjusting the screw-in amount of the anchor bolts 8.

As shown in Figure 6, the free ends of the two rigid cables 2 on the upper side end at point _D1 , and the free ends of the two rigid cables 2 on the lower side end at point _D2 , and points _D1 and _D2 are formed by Elastic cable 6 connections. The elastic cable 6 has three degrees of freedom in the working plane, which are respectively along the horizontal direction X, two translation degrees of freedom in the vertical direction Y, and a rotation degree of freedom around the Z axis perpendicular to the direction of the plane; at the same time, due to the elasticity The flexible cable 6 can be elastically deformed under the action of tension, so its telescopic movement can be regarded as an independent degree of freedom. On these four degrees of freedom of motion, the device can feed back the corresponding force and moment, that is, feed back the grasping force in the stretching direction of the elastic cable 6, so that the operator feels the force sense when grasping the object; In the Y direction, the grasped object or the virtual object represented by the elastic cable 6 interacts with other virtual objects to feel force and torque around the Z axis, so that the operator can feel the real operating force. During use, the pulling force of each rigid flexible cable 2 and the elastic force of the elastic flexible cable 6 form two resultant forces at points D ₁ and D ₂ respectively, so that when the operator's fingers are fixedly connected to points D ₁ and D ₂ Feel force.

After the device is powered on, the initial state of the device needs to be calibrated. When calibrating, as shown in Figure 7, the index finger cuff 4 and the thumb cuff 5 need to be placed flat, and snapped into the calibration groove A105 and the calibration groove B 107 respectively, so that the rigid flexible cable on the same side of the calibration groove A105 and the calibration groove B107 2 is collinear with elastic cable 6. Record the initial lengths l ₁ , l ₂ , l ₃ , l ₄ of the four rigid flexible cables 2 in the calibration frame 102, and at the same time reset the count of the encoder 305 to zero, ie the calibration is completed.

During operation, the operator's thumb is inserted into the thumb cover 5 , and the index finger is inserted into the index finger cover 4 . Both fingertips are worn on the distal knuckles of the fingers. Two fingers can drive the finger sleeves to move on the horizontal plane in the calibration frame 102 on the static platform 1, thereby driving the free end of the rigid flexible cable 2 to move, and the movement of the free end of the rigid flexible cable 2 drives the winch 303 to rotate, thereby driving the motor Shaft 306 turns and encoder 305 counts. The count of the encoder 305 will be converted into the length of the rigid cable 2, thereby calculating the positions of the index finger cuff 4 and the thumb cuff 5.

When the device of the present invention works, there are two states of forward and reverse:

When working in the reverse working state, the operator drives the index finger finger cot 4 and the thumb finger cot 5 to move in the plane defined by the rectangular groove 104, and the length of the rigid flexible cable 2 changes accordingly, and each rigid flexible cable 2 drives The winch 303 rotates, and the rotation of the winch 303 drives the motor shaft 306 to rotate, so that the encoder 305 counts. The count of the encoder 305 will be converted into the length of the rigid cable 2, and the positions of the index finger cuff 4 and the thumb cuff 5 and the elongation length of the elastic cable 6 can be calculated through the kinematics positive solution. Therefore, in the virtual environment, the position of the finger in the virtual environment can be described in real time, and whether it contacts or collides with the virtual object can be detected.

When the device of the present invention works in the forward working state, the motor 301 outputs torque to drive the capstan 303 to rotate, wind the rigid cable 2, and convert the motor torque into the tension of the rigid cable 2. The tension of the rigid flexible cable 2 and the elastic force of the elastic flexible cable 6 form a resultant force to act on the index finger fingertip 4 and the thumb fingertip 5, so that the operator's fingers feel the effect of force.

Claims (8)

1. A four-degree-of-freedom flexible cable-driven human-computer interaction device with gripping force feedback, characterized in that: it includes a static platform, a rigid flexible cable, a flexible cable drive mechanism, a finger cot for the index finger, a thumb cot, and an elastic flexible cable; The static platform is a rectangular structure, and four flexible cable driving mechanisms are arranged symmetrically on the four corners, each flexible cable driving mechanism is connected to a fixed end of a rigid flexible cable, and the free ends of two adjacent rigid flexible cables Connect the index finger cot, and the free ends of the other two rigid cables are connected to the thumb cot, and an elastic cable is connected between the index finger cot and the thumb cot; the flexible cable driving mechanism includes a motor, a motor base, a winch , encoder; the end of the motor is connected with an encoder; the motor is fixed on the motor base, the motor shaft is horizontally inserted into the shaft hole of the winch, the winch is fixed on the motor shaft, and the winch rotates with the motor shaft; the winch Rigid flexible cables are wound on the top; the static platform includes a support plate, a calibration frame, and a guide plate; the calibration frame is glued and fixed on the rectangular support plate; a rectangular groove is opened in the support plate; the four guide plates are evenly fixed and bonded At the four corners of the calibration frame; there are calibration grooves A and B on the calibration frame. After the device is powered on, when it is necessary to calibrate the initial state of the device, the index finger and thumb should be placed flat. Snap into calibration slot A and calibration slot B respectively, make the rigid flexible cables and elastic flexible cables on the same side of calibration slot A and calibration slot B collinear, and record the initial lengths l ₁ and l ₂ of the four rigid flexible cables in the calibration frame , l ₃ , l ₄ , and clear the encoder count at the same time. 2. A four-degree-of-freedom flexible cable-driven human-computer interaction device with gripping force feedback as claimed in claim 1, wherein: the rigid flexible cable is a steel wire rope; the elastic flexible cable is a rubber band or stretched spring. 3. A four-degree-of-freedom cable-driven human-computer interaction device with gripping force feedback as claimed in claim 1, wherein the distances from each edge on the calibration frame to each edge on the support plate are equal; The size of the rectangular groove is the same as the size of the inner frame of the calibration frame; the guide hole plate has four, and each guide hole plate has a guide hole, and the guide holes are in the same surface, pointing to the center of the calibration frame; The calibration groove A and the calibration groove B are both semicircular in structure, and the diameters of the calibration groove A and the calibration groove B are respectively equal to the diameters of the index finger cot and the thumb cot. 4. A four-degree-of-freedom flexible cable-driven human-computer interaction device with grasping force feedback as claimed in claim 1, wherein the thumb and index finger cots respectively refer to grips that require force feedback. The two gripping ends of the tool. 5. A four-degree-of-freedom cable-driven human-computer interaction device with gripping force feedback as claimed in claim 1, wherein the index finger cot includes an outer coat of the index finger cot and an inner sheath of the index finger cot, the outer sheath and the inner sheath Bonding and fixing; the thumb cover includes the outer cover of the thumb cover and the inner cover of the thumb cover, and the inner cover and the outer cover are fixed by bonding; the middle part of the thumb cover and the index finger cover is hollow; the outer cover of the index finger cover is provided with an outer wire hole A , Inner wire hole A, outer wire hole B and inner wire hole B are set on the outer sleeve of the thumb, in which two adjacent rigid flexible cables pass through the outer wire hole A and are tied, and the other two adjacent rigid flexible cables pass through the outer wires The hole B is tied and fixed; the two ends of the elastic cable respectively pass through the inner wire hole A and the inner wire hole B and are tied and fixed. 6. A four-degree-of-freedom cable-driven human-computer interaction device with gripping force feedback as claimed in claim 5, characterized in that: the outer wire hole A on the outer cover of the index finger finger sleeve, the outer wire hole A on the outer cover of the thumb finger sleeve Hole B is co-linear with the axes of the inner wire hole A on the outer cover of the index finger finger sleeve and the inner wire hole B on the outer sleeve of the thumb finger sleeve respectively. 7. A four-degree-of-freedom cable-driven human-computer interaction device with gripping force feedback as claimed in claim 5, characterized in that: the outer wire hole A on the outer cover of the index finger finger sleeve, the outer wire hole A on the outer cover of the thumb finger sleeve The axis of hole B is collinear with the elastic cable. 8. A four-degree-of-freedom cable-driven human-computer interaction device with gripping force feedback as claimed in claim 5, characterized in that: the outer cover of the thumb sleeve and the outer sleeve of the index finger are circular and made of rigid materials; The inner cover of the thumb cover and the inner cover of the index finger cover are made of elastic material.

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