A single-powered steerable mobile robot based on Bricard mechanism

Abstract

The present invention relates to the field of mobile robots, and in particular to a single-power steerable mobile robot based on a Bricard mechanism. The machine is based on a Bricard six-bar mechanism, and two six-bar mechanisms are arranged side by side. The machine is composed of a dual-axis motor (1), a first driving rod (2), a first crawling rod (3), a second crawling rod (4), a first auxiliary rod (5), a first connecting rod (6), a second connecting rod (7), a second auxiliary rod (8), a fourth crawling rod (9), a third crawling rod (10), a second driving rod (11), and a connecting frame (12). The function of the crawling robot moving forward and backward on a single track is realized by driving the forward and reverse rotation of the motor; the function of the crawling robot walking on different tracks is realized by instantaneously changing the speed of the motor. The mechanism has the characteristics of flexible gait and stable crawling, and is suitable for surveying dangerous terrain. At the same time, the mechanism is symmetrically arranged, simple in structure, easy to process and manufacture, and can be applied to the field of education.

Description

Technical Field

[0001] The present invention relates to a single-power steerable mobile robot based on a Bricard mechanism. Specifically, the Bricard six-bar mechanism is used as a basis, two six-bar mechanisms are arranged side by side, and the function of the crawling robot moving forward and backward on a single track is realized by driving the forward and reverse rotation of the motor; the function of the crawling robot moving on different tracks is realized by instantaneously changing the rotation speed of the motor. Background Art

[0002] To realize the function of moving and rotating a ground device, at least two degrees of freedom are required, that is, at least two power sources are required for control and driving. How to realize the function of moving forward and backward and turning the ground device with only one power source, so as to achieve the purpose of simplifying the structure and control, is a topic worth studying.

[0003] As a typical single closed-chain spatial six-bar 6R mechanism, the Bricard mechanism has a wide range of applications in the field of robotics research. Due to the single degree of freedom of the Bricard mechanism, only one motor is needed to drive the entire mechanism to move.

[0004] Chinese patent CN104477270B discloses "a single-power mobile six-rod robot". The robot is based on a spatial six-rod mechanism, and the robot moves as a whole by rolling and swinging its components. The robot turns by probabilistic movement, and its omnidirectional movement is limited. Based on the above content, the present invention proposes a robot that can achieve smooth multi-track crawling by changing the motor speed. Summary of the invention

[0005] The technical problem to be solved by the present invention is: to combine two Bricard six-bar linkages side by side to perform crawling in the same posture to achieve more stable movement; and to realize the functions of forward and backward movement and steering of the crawling robot through a dual-axis motor.

[0006] The single-power steerable mobile robot based on the Bricard mechanism comprises: a dual-axis motor (1), a first driving rod (2), a first crawling rod (3), a second crawling rod (4), a first auxiliary rod (5), a first connecting rod (6), a second connecting rod (7), a second auxiliary rod (8), a fourth crawling rod (9), a third crawling rod (10), a second driving rod (11), and a connecting frame (12).

[0007] The driving motor (1) is a double-shaft motor installed on a connecting frame, and the two shafts of the double-shaft motor are respectively connected to the first driving rod (2) and the second driving rod (8);

[0008] The main body cross section of the first driving rod (2) is circular, a small shaft section is processed on the left side to connect with the motor, a groove and a threaded hole are opened on the right side, and a large-radius spherical protrusion (2-1) is assembled on the part close to the right side to support the mechanism;

[0009] The main body cross section of the first climbing rod (3) is rectangular, with a groove and a circular hole (3-1) on the left side, and a small thickness boss and a circular hole (3-2) on the right side, forming a rotation connection with the first driving rod (2), and the boundaries on both sides are semicircular, and the circular hole (3-1) and the circular hole (3-2) are perpendicular to each other;

[0010] The main body cross section of the second climbing rod (4) is rectangular, and small thickness bosses and circular holes three (4-1) and four (4-2) are processed on both sides. The left side is rotatably connected with the first climbing rod (3), and the boundary shapes on both sides are semicircular. The circular hole three (4-1) and the circular hole four (4-2) are perpendicular to each other.

[0011] The main body cross section of the first auxiliary rod (5) is circular, a small shaft section is processed on the right side, a groove and a circular hole (5-1) are opened on the left side, and a rotation connection is formed with the second crawling rod. The part close to the left side is equipped with a large radius spherical protrusion (5-2) for supporting the mechanism;

[0012] The main body cross section of the first connecting rod (6) is rectangular, a small thickness boss is processed on the right side, six (6-1) and seven (6-2) circular holes perpendicular to each other are opened on both sides, and the left side is rotatably connected with the auxiliary rod. A large radius ball block (6-3) is installed in the middle and a part of the side is cut to support the mechanism;

[0013] The main body cross-section of the connecting frame (12) is rectangular, a motor mounting hole eight (12-1) is provided on the left side for mounting the motor, and a small thickness boss and two circular holes are processed on the right side to form a rotation connection with the first connecting rod and the second connecting rod respectively;

[0014] The spherical block cutting planes and directions of the second connecting rod (7) and the first connecting rod (6) are opposite, and the rest of the structures and dimensions are the same;

[0015] The second auxiliary rod (8) and the first auxiliary rod (5) have the same structure and external dimensions;

[0016] The fourth crawling rod (9) and the second crawling rod (4) have the same structure and external dimensions;

[0017] The third crawling rod (10) and the first crawling rod (3) have the same structure and external dimensions;

[0018] The second driving rod (11) and the first driving rod (2) have the same structure and external dimensions;

[0019] Connection method of parts constituting the mechanism:

[0020] The first drive rod (2) is connected to the motor shaft on one side of the drive motor (1) through a sleeve, the second drive rod (11) is connected to the motor shaft on the other side of the motor (1) through a sleeve, the drive motor housing is connected to the motor mounting hole (12-1) on the connecting frame through an interference fit, the first drive rod (2) and the first climbing rod (3), the first climbing rod (3) and the second climbing rod (4), the second climbing rod (4) and the first auxiliary rod (5), the first auxiliary rod (5) and the first connecting rod (6), the second drive rod (11) and the third climbing rod (10), the third climbing rod (10) and the fourth climbing rod (9), the fourth climbing rod (9) and the second auxiliary rod (8), the second auxiliary rod (8) and the second connecting rod (7), the first connecting rod (6) and the connecting frame (12), and the second connecting rod (7) and the connecting frame (12) are all connected through bolts.

[0021] The first driving rod (2), the first climbing rod (3), the second climbing rod (4), the first auxiliary rod (5), the first connecting rod (6), the second driving rod (11), the third climbing rod (10), the fourth climbing rod (9), the second auxiliary rod (8), and the second connecting rod (7) are completely identical and symmetrically arranged side by side. The first driving rod (2) and the second driving rod (11) make a full circle motion under the action of the driving motor, the connecting joint between the first climbing rod (3) and the second climbing rod (4), and the connecting joint between the third climbing rod (10) and the fourth climbing rod (9) make a spatial circular motion, and the first auxiliary rod (5), the first connecting rod (6), the second connecting rod (7), and the second auxiliary rod (8) play a supporting role.

[0022] The spherical protrusion block 1 (2-1), spherical protrusion block 2 (5-2), spherical protrusion block 4 (8-1), and spherical protrusion block 5 (11-1) are completely identical, and the spherical protrusion block 3 (6-3) and the spherical protrusion block 6 (7-1) have opposite cutting directions. The sizes of the six spherical blocks are all larger than the cross-sectional size of the rod, forming point contact with the ground, thereby generating a spatial difference.

[0023] The driving motor (2) is a dual-shaft motor.

[0024] Beneficial results of the present invention: The single-powered steerable mobile robot based on the Bricard mechanism described in the present invention is a single-degree-of-freedom mechanism. By arranging two Bricard mechanisms side by side to perform the same posture movement, the mechanism can crawl more stably; by using the forward and reverse rotation of the dual-axis motor to realize the single-track forward and backward movement of the mechanism; by instantaneously changing the motor speed, the mechanism can realize multi-track movement. The mechanism has the characteristics of flexible gait and stable crawling, and is suitable for surveying dangerous terrain. At the same time, the mechanism is symmetrically arranged, simple in structure, easy to process and manufacture, and can be applied in the field of education, allowing students to further understand the charm of the spatial linkage mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Single-powered steerable mobile robot based on Bricard mechanism

[0026] Figure 2 First drive rod structure diagram

[0027] Figure 3 The first crawling rod structure diagram

[0028] Figure 4 The second crawling rod structure diagram

[0029] Figure 5 First auxiliary rod structure diagram

[0030] Figure 6 First connecting rod structure diagram

[0031] Figure 7 Second connecting rod structure diagram

[0032] Figure 8 Structural diagram of the second auxiliary rod

[0033] Fig. 9 The third crawling rod structure diagram

[0034] Fig.10 The fourth creeping rod structure diagram

[0035] Fig.11 Second drive rod structure diagram

[0036] Fig.12 Connection frame structure diagram

[0037] Fig.13 Schematic diagram of the single-track forward dynamic action of the motor forward drive mechanism

[0038] Fig.14 Schematic diagram of the single-track backward gait action of the motor reverse drive mechanism

[0039] Fig.15 Schematic diagram of changing the motor speed to switch the trajectory gait action DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0041] like Figure 1 As shown, a single-power steerable mobile robot based on a Bricard mechanism is a closed-chain mechanism, comprising a dual-axis motor (1), a first driving rod (2), a first crawling rod (3), a second crawling rod (4), a first auxiliary rod (5), a first connecting rod (6), a second connecting rod (7), a second auxiliary rod (8), a fourth crawling rod (9), a third crawling rod (10), a second driving rod (11), and a connecting frame (12);

[0042] like Figure 2 As shown, the main body cross section of the first driving rod (2) is circular, a small shaft section is processed on the left side to connect with the motor, a groove and a threaded hole are opened on the right side, and a large-radius spherical protrusion (2-1) is assembled near the right side to support the mechanism;

[0043] like Figure 3 As shown, the main body section of the first climbing rod (3) is rectangular, with a groove and a circular hole 1 (3-1) on the left side, and a small thickness boss and a circular hole 2 (3-2) processed on the right side, forming a rotation connection with the first driving rod (2), and the boundaries on both sides are semicircular, and the circular hole 1 (3-1) and the circular hole 2 (3-2) are perpendicular to each other;

[0044] like Figure 4 As shown, the main body cross section of the second climbing rod (4) is rectangular, and small thickness bosses and circular holes three (4-1) and four (4-2) are processed on both sides. The left side is rotatably connected with the first climbing rod (3), and the boundary shapes on both sides are semicircular. The circular hole three (4-1) and the circular hole four (4-2) are perpendicular to each other;

[0045] like Figure 5 As shown, the main body cross section of the first auxiliary rod (5) is circular, a small shaft section is processed on the right side, a groove and a circular hole (5-1) are opened on the left side, and a rotation connection is formed with the second crawling rod. The part close to the left side is equipped with a large radius spherical protrusion (5-2) for supporting the mechanism;

[0046] like Figure 6 As shown, the main body cross section of the first connecting rod (6) is rectangular, a small thickness boss is processed on the right side, and six (6-1) and seven (6-2) circular holes perpendicular to each other are opened on both sides. The left side is rotatably connected with the auxiliary rod, and a large radius ball block three (6-3) is installed in the middle and a part of the side is cut to support the mechanism;

[0047] like Fig.12 As shown, the main body cross-section of the connecting frame (12) is rectangular, a motor mounting hole eight (12-1) is provided on the left side for mounting the motor, and a small thickness boss and two circular holes are processed on the right side to form a rotation connection with the first connecting rod and the second connecting rod respectively;

[0048] like Figure 7 As shown, the spherical block cutting planes and directions of the second connecting rod (7) and the first connecting rod (6) are opposite, and the rest of the structures and dimensions are the same;

[0049] like Figure 8 As shown, the second auxiliary rod (8) and the first auxiliary rod (5) have the same structure and external dimensions;

[0050] like Fig. 9As shown, the fourth crawling rod (9) and the second crawling rod (4) have the same structure and external dimensions;

[0051] like Fig.10 As shown, the third climbing rod (10) and the first climbing rod (3) have the same structure and external dimensions;

[0052] like Fig.11 As shown, the second driving rod (11) and the first driving rod (2) have the same structure and external dimensions;

[0053] like Figure 1 As shown, the driving rod (2) is connected to the motor shaft on one side of the driving motor (1) through a sleeve, the second driving rod (11) is connected to the motor shaft on the other side of the motor (1) through a sleeve, the driving motor housing is connected to the motor mounting hole (12-1) on the connecting frame through an interference fit, the first driving rod (2) and the first climbing rod (3), the first climbing rod (3) and the second climbing rod (4), the second climbing rod (4) and the first auxiliary rod (5), the first auxiliary rod (5) and the first connecting rod (6), the second driving rod (11) and the third climbing rod (10), the third climbing rod (10) and the fourth climbing rod (9), the fourth climbing rod (9) and the second auxiliary rod (8), the second auxiliary rod (8) and the second connecting rod (7), the first connecting rod (6) and the connecting frame (12), and the second connecting rod (7) and the connecting frame (12) are all connected through bolts.

[0054] Specific usage:

[0055] The single-powered steerable mobile robot based on the Bricard mechanism can realize the function of multi-track crawling. By keeping the two spatial six-bar mechanisms on both sides of the motor arranged side by side and keeping the postures of the two mechanisms the same at all times, the stability of the entire robot crawling process can be increased.

[0056] The single-powered steerable mobile robot based on the Bricard mechanism can move forward and backward on a single trajectory.

[0057] like Fig.13 As shown in (a)-(e), the robot completes a single trajectory forward in one cycle driven by the motor. Fig.13 (a) is the initial state of the robot. The first auxiliary rod, the first connecting rod, the second auxiliary rod, and the spherical protrusions on the second connecting rod are in contact with the ground for support. The drive motor is in a locked state, and the centers of each rod are in the same plane. Under the positive drive of the motor, the first climbing rod, the second climbing rod, the third climbing rod, and the fourth climbing rod climb up in the same posture. The joints at the connection between the first climbing rod and the second climbing rod, and the joints at the connection between the third climbing rod and the fourth climbing rod move in space in a semicircular trajectory. Fig.13 (b) The motor continues to rotate forward at a constant speed, and the two joints continue to move in a semicircular trajectory until they fall to the ground. Fig.13 (c) The motor continues to rotate, and the first and third climbing rods come into contact with the ground to generate static friction. Under the action of static friction, the entire mechanism is pushed to maintain a specific trajectory to achieve Fig.13 (d) The motor keeps rotating and the mechanism returns to its initial position. Fig.13 (e).

[0058] like Fig.14 As shown in (a)-(e), the robot completes a single-trajectory retreat cycle driven by the motor. Fig.14 (a) is the initial state of the robot. The first auxiliary rod, the first connecting rod, the second auxiliary rod, and the spherical protrusions on the second connecting rod are in contact with the ground for support. The drive motor is in a locked state, and the centers of the rods are in the same plane. Under the reverse drive of the motor, the first climbing rod, the second climbing rod, the third climbing rod, and the fourth climbing rod climb up in the same posture. The joints at the connection between the first climbing rod and the second climbing rod, and the joints at the connection between the third climbing rod and the fourth climbing rod move in space in a semicircular trajectory. Fig.14 (b) The motor speed remains unchanged and continues to reverse, and the two joints continue to move in a semicircular trajectory until they fall to the ground. Fig.14 (c) The motor continues to rotate, and the first and third climbing rods come into contact with the ground to generate static friction. Under the action of static friction, the entire mechanism is pushed to maintain a specific trajectory to achieve Fig.14 (d) The motor keeps reversing and the mechanism returns to its initial position. Fig.14 (e).

[0059] The single-powered steerable mobile robot based on the Bricard mechanism can perform multi-track crawling.

[0060] like Fig.15 As shown in (a)-(d), the robot switches between trajectories by instantaneously changing the motor speed. The robot first reaches Fig.15 (a) state, at this time, the joint at the connection between the first climbing rod and the second climbing rod, and the joint at the connection between the third climbing rod and the fourth climbing rod move in space in a semicircular trajectory to Fig.15 (b) The position shown. At this time, the motor speed is changed. The contact points of the first and third crawling rods with the ground will change the magnitude, direction and working time of the static friction between the joints of the mechanism and the ground at different moving speeds, thereby changing the crawling trajectory to achieve Fig.15 (c) The motor speed continues to change, and the mechanism continues to change the crawling trajectory to reach Fig.15 (d) status.

Claims

1. A single-powered steerable mobile robot based on the Bricard mechanism. Features: The mechanism is a closed chain mechanism arranged in parallel, comprising: a driving motor (1), a first driving rod (2), a first crawling rod (3), a second crawling rod (4), a first auxiliary rod (5), a first connecting rod (6), a second connecting rod (7), a second auxiliary rod (8), a fourth crawling rod (9), a third crawling rod (10), and a second driving rod (11); The driving motor (1) is a double-shaft motor installed on a connecting frame, and the two shafts of the double-shaft motor are respectively connected to the first driving rod (2) and the second driving rod (11); The main body cross section of the first driving rod (2) is circular, a small shaft section is processed on the left side to connect with the motor, a groove and a threaded hole are opened on the right side, and a large-radius spherical protrusion (2-1) is assembled on the part close to the right side to support the mechanism; The main body cross section of the first climbing rod (3) is rectangular, with a groove and a circular hole (3-1) on the left side, and a small thickness boss and a circular hole (3-2) on the right side, forming a rotation connection with the first driving rod (2), and the boundaries on both sides are semicircular, and the circular hole (3-1) and the circular hole (3-2) are perpendicular to each other; The main body cross section of the second climbing rod (4) is rectangular, and small thickness bosses and circular holes (4-1) and (4-2) are processed on both sides. The left side is rotatably connected with the first climbing rod (3), and the boundary shapes on both sides are semicircular. The circular holes (4-1) and (4-2) are perpendicular to each other. The main body cross section of the first auxiliary rod (5) is circular, a small shaft section is processed on the right side, a groove and a circular hole (5-1) are opened on the left side, and a rotation connection is formed with the second crawling rod. The part close to the left side is equipped with a large radius spherical protrusion block (5-2) for supporting the mechanism; The main body cross section of the first connecting rod (6) is rectangular, a small thickness boss is processed on the right side, and a six circular hole (6-1) and a seven circular hole (6-2) perpendicular to each other are opened on both sides. The left side is rotatably connected with the auxiliary rod, and a large radius ball block (6-3) is installed in the middle and a part of the side is cut to support the mechanism; The main body cross section of the connecting frame (12) is rectangular, a motor mounting hole (12-1) is provided on the left side for mounting the motor, and a small thickness boss and two circular holes are processed on the right side to form a rotational connection with the first connecting rod and the second connecting rod respectively; The spherical block cutting planes and directions of the second connecting rod (7) and the first connecting rod (6) are opposite, and the rest of the structures and dimensions are the same; The second auxiliary rod (8) and the first auxiliary rod (5) have the same structure and external dimensions; The fourth crawling rod (9) and the second crawling rod (4) have the same structure and external dimensions; The third crawling rod (10) and the first crawling rod (3) have the same structure and external dimensions; The second driving rod (11) and the first driving rod (2) have the same structure and external dimensions; The first drive rod (2) is connected to the motor shaft on one side of the drive motor (1) through a sleeve, the second drive rod (11) is connected to the motor shaft on the other side of the motor (1) through a sleeve, the drive motor housing is connected to the motor mounting hole (12-1) on the connecting frame through an interference fit, the first drive rod (2) and the first climbing rod (3), the first climbing rod (3) and the second climbing rod (4), the second climbing rod (4) and the first auxiliary rod (5), the first auxiliary rod (5) and the first connecting rod (6), the second drive rod (11) and the third climbing rod (10), the third climbing rod (10) and the fourth climbing rod (9), the fourth climbing rod (9) and the second auxiliary rod (8), the second auxiliary rod (8) and the second connecting rod (7), the first connecting rod (6) and the connecting frame (12), and the second connecting rod (7) and the connecting frame (12) are all connected through bolts.

2. A single-powered steerable mobile robot based on a Bricard mechanism as claimed in claim 1, Features: The first driving rod (2), the first climbing rod (3), the second climbing rod (4), the first auxiliary rod (5), the first connecting rod (6), the second driving rod (11), the third climbing rod (10), the fourth climbing rod (9), the second auxiliary rod (8), and the second connecting rod (7) are completely identical and symmetrically arranged side by side. The connecting joints of the first climbing rod (3) and the second climbing rod (4) and the connecting joints of the third climbing rod (10) and the fourth climbing rod (9) perform spatial circular motion, while the first auxiliary rod (5), the first connecting rod (6), the second connecting rod (7), and the second auxiliary rod (8) play a supporting role.

3. A single-powered steerable mobile robot based on a Bricard mechanism as claimed in claim 1, Features: The spherical protrusion block 1 (1-1), the spherical protrusion block 2, the spherical protrusion block 3, the spherical protrusion block 4 (8-1), the spherical protrusion block 5 (9-2) and the spherical protrusion block 6 (10-1) are completely identical, and their sizes are larger than the cross-sectional size of the rod, generating a spatial difference in point contact with the ground.

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