CN108789461B

CN108789461B - Mechanical foot claw for multi-foot robot

Info

Publication number: CN108789461B
Application number: CN201810585128.7A
Authority: CN
Inventors: 徐坤; 李斌; 丁希仑
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2018-06-08
Filing date: 2018-06-08
Publication date: 2020-10-30
Anticipated expiration: 2038-06-08
Also published as: CN108789461A

Abstract

The invention discloses a mechanical foot claw for a multi-foot robot, which is divided into two parts by a physical mechanical structure: one is a mechanical foot structure, the sole of which is in a hemispheroid form, the middle of which is provided with 3 supporting rods for supporting, and a cylindrical body for placing a motor is arranged above the mechanical foot structure and can be connected with a leg structure; the second is a three-finger under-actuated connecting rod type mechanical paw, and torsion springs are arranged between the first knuckle and the second knuckle and between the second knuckle and the third knuckle. The mechanical foot and the mechanical claw form a whole through the moving pair constraint of the sliding block and the rod piece, and the grabbing and supporting function switching is realized through the foot claw structure switching. A driving system of the mechanical gripper is built on the basis of a physical mechanical structure, the driving system is a linear stepping motor with a trapezoidal screw rod, the motor is controlled by a matched driver, and the motor driver is connected to a transformer for converting 220V into 12V.

Description

Mechanical foot claw for multi-foot robot

Technical Field

The invention belongs to the fields of robotics, mechanics and the like, and relates to a mechanical foot claw with the functions of mechanical arm grabbing and mechanical foot supporting for a multi-foot robot.

Background

The ground mobile robot is a highly integrated intelligent robot system, and can be roughly divided into wheeled robots, legged robots, tracked robots, other bionic mobile robots and the like according to different movement mechanism modes. Among them, the legged robot receives more and more attention from various scholars and industries due to its better mobility and superior adaptability to terrain. The multi-legged robot developed at present is widely applied to the fields of heavy object transportation, volcano, seabed and other terrain complex area detection, education and entertainment and the like, but the existing multi-legged walking robot is usually only used as a moving platform.

The mechanical legs have the function of supporting walking, the mechanical arms have the functions of grabbing, carrying objects and operating tools, although the functions are different, the structure has common points, and the mechanical legs are all in a joint type structure. In nature, the mechanism of leg-arm fusion and hand-foot reuse is ubiquitous in primates. Most primates still keep four limbs walking mode, and its forelimb develops into the arm, supports body weight as the leg during walking, operates as the arm during snatching, realizes leg and arm integration function, and the thumb can be held with other four fingers to realize the hand and foot multiplexing function. Many researchers around the world have studied the moving operation of the multi-legged robot, but many multi-legged robots having the moving operation function perform the work only by configuring a specific robot arm. The function of grabbing objects is realized by the additional mechanical arm, which not only increases the weight of the robot, but also reduces the working space of the mechanical gripper due to the mutual influence of the mechanical foot and the mechanical arm.

Through the hand and foot integration design of robot, make end effector have the sufficient function that supports walking and manipulator snatch the object of machinery concurrently, the leg branch of polypod robot possesses the operating function of arm, realizes the multiplexing of leg arm function, can effectively improve this defect, promotes the robot practicality that the leg arm is multiplexing, the hand and foot is integrated, expands the big sufficient robot application of portion, provides new thinking for the multiplexing research of robot staff (claw) foot simultaneously.

Disclosure of Invention

Aiming at the problems, the invention designs a mechanical foot claw for the multi-foot robot by imitating the four limb movement mechanism of primates, adds a mechanical arm structure on the basis of the foot structure of the traditional multi-foot robot, and organically combines the two to integrate the two into a whole mechanical foot claw.

The invention relates to a mechanical foot claw for a multi-foot robot, which is provided with a mechanical foot and a mechanical arm; the manipulator adopts a connecting rod type under-actuated finger mechanism which is a simulated health driving mechanism and comprises a driving rod, a middle knuckle, a far knuckle and seven transmission rods. The seven transmission rods are respectively a main transmission rod, a near knuckle inner side transmission rod, a near knuckle outer side transmission rod, a middle knuckle inner side transmission rod and a middle knuckle outer side transmission rod; the output end of the driving rod is hinged with the middle position of the main driving rod through a pin shaft, and two ends of the main driving rod are respectively hinged with the tail ends of the near knuckle inner side driving rod and the near knuckle outer side driving rod through pin shafts; the middle knuckle is of a triangular structure, and three angles of the middle knuckle are respectively an angle a, an angle b and an angle c; the angle a is hinged with the front end of the inner transmission rod of the near knuckle and the tail end of the inner transmission rod of the middle knuckle through a pin shaft; the angle b is hinged with the front end of the near knuckle outer side transmission rod 206 through a pin shaft; the corner c is hinged with the tail end of the transmission rod at the outer side of the middle knuckle through a pin shaft; a first torsion spring is arranged on the pin shaft at the angle a, and two ends of the first torsion spring are respectively fixed with the near knuckle inner side transmission rod and the middle knuckle inner side transmission rod; meanwhile, a second torsion spring is arranged on a pin shaft at the hinged part of the middle knuckle inner side transmission rod and the far knuckle, and two ends of the second torsion spring are respectively fixed with the middle knuckle inner side transmission rod and the far knuckle; the front ends of the middle knuckle inner side transmission rod and the middle knuckle outer side transmission rod are respectively hinged with a connecting piece designed at the tail end of a far knuckle through a pin shaft, and the hinged positions are adjacent

The mechanical arms are uniformly distributed in the circumferential direction and are arranged on the periphery of the mechanical foot; the mechanical arm drives the three circumferential mechanical arms to move up and down through the driving motors arranged on the mechanical feet, and simultaneously drives the three mechanical arms to grab.

The invention has the advantages that:

1. the mechanical foot claw for the multi-foot robot has the grabbing function of the mechanical hand and the supporting function of the mechanical foot, does not need to be provided with an additional operating arm, and is relatively simple in structure and relatively lighter in weight.

2. The mechanical foot claw for the multi-foot robot is an integrated structure by initiatively integrating the mechanical foot and the under-actuated finger, the working freedom degrees of the hand-foot function switching process and the object grabbing process of the finger are always one, and the two processes can be driven by one motor, so that the control is simpler.

Drawings

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

FIG. 2 is a schematic structural view of a mechanical foot in the mechanical foot claw of the present invention;

FIG. 3 is a schematic view of a fixing manner of a mechanical foot support rod in the mechanical foot claw according to the present invention;

FIG. 4 is a schematic structural diagram of a manipulator in the mechanical foot gripper according to the present invention;

FIG. 5 is a schematic structural view of a protective housing of the mechanical foot gripper of the present invention;

FIG. 6 is a schematic structural view of the mechanical foot gripper of the present invention in a mechanical foot supporting state;

FIG. 7 is a schematic structural view of the mechanical paw of the present invention in a manipulator grabbing state;

fig. 8 is a schematic view of the state of the mechanical paw of the invention when it completely grabs the ball.

In the figure:

1-mechanical foot 2-mechanical arm 3-stepping motor

4-upper slide block 5-lower slide block 101-sole

102-support rod 103-lower fixing piece 103 a-lower lug

104-upper fixture 104 a-upper lug 105-flat recess

201-drive rod 202-middle knuckle 203-distal knuckle

204-main drive link 205-proximal knuckle inboard drive link 206-proximal knuckle outboard drive link

207-middle knuckle inner transmission rod 208-middle knuckle outer transmission rod 301-driving screw rod

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention designs a mechanical foot claw for a multi-foot robot, which comprises a mechanical foot 1 and a mechanical hand 2, and is shown in figure 1.

The mechanical foot 1 comprises four parts, namely a sole 101, a support rod 102, a lower fixing part 103 and an upper fixing part 104, as shown in fig. 2. The lower part of the sole 101 is a spherical cambered surface, the spherical cambered surface is in spherical hinge contact with the ground, the bearing area is relatively large, the structural stability of the robot can be kept, and the robot is suitable for various complex terrains. The upper part of the sole 101 is a plane for mounting the support rod 102. The number of the support rods 102 is three, the support rods are vertically arranged and evenly distributed in the circumferential direction, and the bottom ends of the support rods are fixed with the sole 101 through slotted pan head screws after penetrating through flat concave holes 105 designed on the outer edge of the sole 101 from the lower part of the sole 101, as shown in fig. 3. The upper end of the support rod 102 is designed with a connecting platform for supporting the lower fixing member 103. The lower fixing member 103 is of a flat plate structure, six lower lugs 103a are uniformly designed in the circumferential direction, wherein three lower lugs 103a at intervals are respectively attached to connecting platforms at the upper ends of the three support rods 102, and the other three lower lugs 103a are used for connecting the protective shell 5. The upper fixing piece 104 is of a barrel-shaped structure, three upper lugs 104a are arranged on the lower end in the circumferential direction, and the three upper lugs 104a are respectively attached to the three lower lugs 103 a; the upper end is of a flange structure and is used for being connected with the legs of the multi-legged robot. The connection among the connecting platform, the lower lug 103a and the upper lug 104a which are mutually attached is realized through bolts, and meanwhile, the relative position among the three support rods 102 is fixed. Go up the inside step motor 3 that is used for placing of mounting 102, step motor 3 passes down mounting 102, goes up mounting 103 and step motor 3 from 4 ~ 5mm screw hole threaded connection in the area through the cross recess screw in proper order, realizes step motor 3's fixed. Meanwhile, the stepping motor 3 is a linear stepping motor with a trapezoidal screw rod and is controlled by a matched motor driver, and the motor driver is connected with a transformer for converting 220V into 12V; and a driving screw rod 301, wherein the driving screw rod 301 penetrates through the central openings of the lower fixing piece 102 and the upper fixing piece 103, as shown in figure 1.

The number of the mechanical arms 2 is three, and the three mechanical arms are circumferentially and uniformly distributed on the periphery of the mechanical leg 1, as shown in fig. 1. The three manipulators 2 are link type under-actuated finger mechanisms simulating a fitness drive mechanism, have the same structure and comprise a drive rod 201, a middle knuckle 202, a far knuckle 203 and seven drive rods. Seven transmission rods are respectively a main transmission rod 204, a near knuckle inner transmission rod 205, a near knuckle outer transmission rod 206, a middle knuckle inner transmission rod 207 and a middle knuckle outer transmission rod 208, as shown in fig. 4.

The output end of the driving rod 201 is hinged to the middle of the main driving rod 202 through a pin, and two ends of the main driving rod 202 are hinged to the ends of the near knuckle inner side driving rod 205 and the near knuckle outer side driving rod 206 through pins. The middle knuckle is of a triangular structure, and three angles of the middle knuckle are respectively an angle a, an angle b and an angle c; the angle a is hinged with the front end of the near knuckle inner side transmission rod 205 and the tail end of the middle knuckle inner side transmission rod 207 through a pin shaft; the angle b is hinged with the front end of the near knuckle outer side transmission rod 206 through a pin shaft; the corner c is hinged with the tail end of the middle knuckle outer transmission rod 208 through a pin shaft. A first torsion spring is arranged on the pin shaft at the angle a, and two ends of the first torsion spring are respectively fixed with the near knuckle inner side transmission rod 205 and the middle knuckle inner side transmission rod 207; meanwhile, a second torsion spring is arranged on a hinge pin at the hinged part of the middle knuckle inner side transmission rod 207 and the far knuckle 203, and two ends of the second torsion spring are respectively fixed with the middle knuckle inner side transmission rod 207 and the far knuckle 203. The front ends of the middle knuckle inner transmission rod 207 and the middle knuckle outer transmission rod 208 are respectively hinged with a connecting piece designed at the tail end of a far knuckle through pin shafts, and the hinged positions are adjacent. Therefore, when the driving rod 201 is fixed in the circumferential direction of the mechanical leg 1 and the main driving rod 204 is fixed in the circumferential direction and the axial direction of the mechanical leg 1, the driving rod 201 is controlled to move towards the sole 101, and the three mechanical arms 2 can adaptively envelop and grab objects through the transmission of the driving rods and the damping constraint of the torsion springs.

A plane a is designed at the end part of the tail end of the near knuckle inner side transmission rod 205 and is used for being matched with the end surface of the tail end of the middle knuckle inner side transmission rod 207 to realize the rotation limit of the near knuckle inner side transmission rod 205; similarly, the front end of the middle knuckle inner transmission rod 207 is designed with a plane B for matching with the end surface of the distal knuckle 203 to limit the rotation of the middle knuckle inner transmission rod 207. Therefore, when the manipulator 2 starts to move, the proximal knuckle inner transmission rod 205 and the middle knuckle inner transmission rod 207 can rotate in the same direction through the limiting action of the plane a and the plane B, as shown in fig. 4.

The three mechanical arms 2 with the structure are connected with the mechanical foot 1 through the upper slide block 4 and the lower slide block 5 in the same way, as shown in figure 1. The upper slider 4 and the lower slider 5 are circumferentially provided with three openings for the three support rods 102 to pass through, so that the upper slider 4 and the lower slider 5 are sleeved on the three support rods 102. Three hinged joints are designed on the upper sliding block 4 and the lower sliding block 5 in the circumferential direction; three hinged joints on the upper sliding block 4 are respectively hinged with the input ends of the driving rods 201 in the three mechanical arms 2 through pin shafts; the three hinges on the lower slider 5 are respectively hinged with the hinged parts of the near knuckle inner side transmission rod 205 and the middle knuckle inner side transmission rod 207 of the three manipulators, and the hinging among the three parts is realized through pin shafts for realizing the hinging of the near knuckle inner side transmission rod 205 and the middle knuckle inner side transmission rod 207. Three compression springs are circumferentially arranged between the upper sliding block 4 and the lower sliding block, the three compression springs are respectively sleeved on the three supporting rods, and the upper end and the lower end of each spring are respectively bonded with the upper sliding block and the lower sliding block through AB glue. The upper slider 4 and the lower slider 5 are respectively provided with lightening holes which are uniformly distributed in the circumferential direction, and the three lightening holes are positioned between the openings for the three support rods 102 to pass through. The center of the upper sliding block 4 is provided with a hole which is fixedly sleeved on a nut on a self-provided screw rod of the stepping motor; the screw rod also passes through a central opening designed on the lower slide block 5. Therefore, the trapezoidal screw rod can be driven to rotate through the stepping motor, and the upper sliding block 4 is driven to move up and down.

The protective shell 5 is of a cylindrical structure, is sleeved outside the whole mechanical paw, is circumferentially provided with three protective cavities 501 for placing three mechanical hands, is circumferentially provided with three connecting platforms 502 on the top surface, and is fixedly connected with three lower lugs 103a of the lower fixing piece 103, which are used for connecting the protective shell 5, through bolts, as shown in fig. 5.

Initially, the three-handed manipulator 2 is integrally located between the support rod 102 and the protective housing 5, and the stepping motor is in contact with the lower fixing member 102 through a nut on a lead screw, as shown in fig. 6, and at this time, the mechanical foot claw is in a mechanical foot supporting state.

When the hands and feet start to be switched, under the constraint action of the spring and the torsion spring, the manipulator 2 only has the freedom degree of movement along the axial direction of the screw rod, the manipulator 2 is driven by the stepping motor to wholly slide towards the sole 101 until the lower sliding block 3 is contacted with the upper end of the sole 101, the manipulator 2 fingers completely extend out of the respective protection cavity 501 at the moment, and the rotating speed of the stepping motor is reduced. The lower slider 3 is subjected to two opposite forces of the sole 101 and the compression spring, and is kept in a static state, and the mechanical foot claw is changed into a manipulator state at the moment, as shown in fig. 7.

After the manipulator state is converted, the upper slider 3 continues to slide towards the sole 101, a driving force towards the sole 101 is applied to the driving rod 201, and when the proximal knuckle inner side transmission rod 205 and the middle knuckle inner side transmission rod 207 are in the state, the three manipulators 2 respectively rotate around the hinge shafts between the three manipulators and the lower slider 4; until the near knuckle inner transmission rod 205 contacts with the object to be grasped, the near knuckle inner transmission rod 205 is not moved, the middle knuckle inner transmission rod 207 and the far knuckle 203 continue to rotate, and after the near knuckle inner transmission rod and the far knuckle 203 sequentially contact with the object, the object is enveloped and grasped by the three mechanical hands 2, and a stable grasping state is maintained, as shown in fig. 8.

After the manipulator 2 grabs the object and places in the assigned position, the motor gyration is loosened and is snatched the object, and the finger becomes the state shown in fig. 7 under the effect of structural constraint plane A and plane B, and at this moment, the spring resumes initial length, and the torsional spring resumes initial condition, and plane A and plane B laminate with corresponding side respectively, and lower slider still contacts with sole upper surface. Under the limitation of the compression spring, the manipulator slides towards the lower fixing piece 102 in a single integral mode again until the nut on the lead screw of the stepping motor is contacted with the lower fixing piece 102, the stepping motor 3 stops rotating, and the mechanical foot claw is converted into an initial state.

Claims

1. A mechanical foot claw for a multi-foot robot is provided with a mechanical foot and a mechanical arm; the method is characterized in that:

the mechanical arms are uniformly distributed in the circumferential direction and are arranged on the periphery of the mechanical foot; the mechanical arm drives the three circumferential mechanical arms to move up and down through a driving motor arranged on the mechanical foot, and simultaneously drives the three mechanical arms to grab;

the mechanical arm is connected with the mechanical foot through the upper sliding block and the lower sliding block; wherein the upper sliding block is sleeved on the mechanical foot, and the upper and lower positions are driven by a driving motor; the lower sliding block is sleeved on the mechanical foot and connected with the upper sliding block through a circumferential spring; the driving rods in the three mechanical arms are hinged with the upper sliding block, and the three hinged joints on the lower sliding block are respectively hinged with the hinged parts of the first knuckles in the three mechanical arms; meanwhile, the upper sliding block is fixed on a nut on a self-contained screw rod of the driving motor; therefore, the screw rod is driven to rotate by the driving motor, and the mechanical arm is further driven to move axially along the mechanical foot;

initially, when a nut on a lead screw of a driving motor is in contact with a lower fixing piece, the driving motor is in a mechanical foot supporting state; the manipulator is driven to slide towards the sole by the driving motor until the lower sliding block is contacted with the upper end of the sole, and the manipulator is in a manipulator state at the moment; the upper sliding block continuously slides towards the sole, so that the manipulator envelops and grabs objects.

2. The robotic gripper for a multi-legged robot, according to claim 1, wherein: the mechanical foot comprises a sole, a support rod, a lower fixing piece and an upper fixing piece; the supporting rods are circumferentially arranged on the upper surface of the sole; the upper fixing piece, the lower fixing piece and the top of the support rod are fixedly connected from top to bottom; the interior of the upper fixing piece is used for placing a driving motor.

3. The mechanical foot claw for the multi-legged robot as claimed in claim 2, wherein: the lower part of the sole is a spherical cambered surface.

4. The robotic gripper for a multi-legged robot, according to claim 1, wherein: still have the protective housing, the protective housing cover is outside in the manipulator, and circumference all is equipped with three protection chamber that is used for placing three manipulators.