KR100841184B1 - Humanoid Robot Foots Having Multi-Platforms of Parallel Structure - Google Patents

Abstract

       The present invention relates to a robot foot structure used in a humanoid robot, and to a parallel mechanism-type multi-platform humanoid robot foot which enables the generation of a step similar to a normal walking human and allows an efficient step.

       The present invention consists of four platforms: a front-left platform, a front-right platform, an intermediate platform, and a back-platform, the suspension platform having two active translational joints located at the base to generate two degrees of freedom rotational motion. The front-left platform, the front-right platform, and the rear-platforms each having a chain of six degrees of freedom joints comprising one degree of freedom active translational joint fixed to the front one side of the base, respectively Each rotatable structure is connected to the platform.

      According to the present invention, the intermediate platform generates a pitch angular movement and a roll angular movement to correspond to the ankle movement of the person, and the relative movement of the front / middle platform generates the motion of the material's MTP (MatertarsalPhalengeal) joint, and the middle / rear platform Relative movement of can achieve the effect of performing the human step by generating the relative movement of the foot when landing, and can be effectively applied to the artificial foot of the disabled.

Humanoid, Relative Angle of Foot, Parallel Mechanism, Walking, Multi-Platform, Foot

Description

Humanoid Robot Foots Having Multi-Platforms of Parallel Structure}

1 is a perspective view of an overall view of a parallel instrumented multi-platform humanoid robot foot according to the present invention;

Figure 2 is a schematic diagram showing the rotational movement of the intermediate platform provided on the humanoid robot foot in accordance with the present invention;

Figure 3 is a block diagram showing the joint arrangement provided in the two degrees of freedom parallel mechanism portion of the rotation-translation in the humanoid robot foot according to the present invention;

4 is an operation explanatory diagram illustrating an operation relationship made in a two degrees of freedom parallel mechanism part of rotation-translation in the humanoid robot foot according to the present invention;

5 is a schematic diagram showing a link-joint connection relationship between the intermediate platform and the front / back-platform in the humanoid robot foot according to the present invention;

6 is an explanatory view showing a total of five degrees of freedom motion obtained from the humanoid robot foot according to the present invention;

7 is a diagram generally illustrating the link-joint relationship of a parallel instrumented multi-platform humanoid robot foot according to the present invention.

       <Explanation of symbols for the main parts of the drawings>

10 .... intermediate platform 11 .... front-right platform

12 .... front-left platform 14 .... back-platform

20 .... 2 degrees of freedom support 21 .... 4-bar link

22 .... pitch angle connection 25 .... 2 degrees of freedom parallel mechanism

30 .... Bass U1, U2, U3, U4, U5, U6, U7, U8 .... Universal joints

P1 , P2 , P3 , P4 , P5 .... Active Translation Joints (Drivers)

P1, P2, P3 .... manual translation

R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11 .... Rotating Joint

S .... Ball joints θ, θ2, θ3, θ4 .... Pitch angle

Φ ... Roll Angle Re (θ) .... Pitch Angle Movement

Re (φ) ... roll angular movement Lm .... translation

       The present invention relates to the structure of a robot foot used in a humanoid robot that allows a more natural walk, such as a human. More specifically, the intermediate platform and the front-left platform, the front-right platform, and the rear-platforms And a parallel instrumented multi-platform humanoid robot foot that includes pitch angular motion and roll angular motion, and has a relative degree of freedom with respect to each other to allow natural walking like a human foot.

       Most humanoid robot feet developed to date are made of a single rigid body, which shows a walking pattern different from normal humans in the generation of gait trajectories. Therefore, the soles of the feet are always horizontal when walking, so heel strike, foot flat, heel rise, and toe that occur during the stance phase in normal human walking. It is not possible to naturally generate a series of steps of human walking.

       Therefore, the conventional robot foot has a poor adaptability in maintaining a stable contact with the ground due to its structure, and thus cannot realize a skilled mobility like a human being. Recent Humanoid Studies (K. Nishiwaki and S. Kagami, “Toe joint that enhances bipedal and full body motion,” IEEE Int. Conf. On Rob. And Auto. (ICRA 2002), pp. 3105-3110, 2002.) Presented a humanoid with a toe joint attached to the foot. In straight forward walking, the addition of one degree of freedom toe joint may allow for faster walking, and the MTP joint of the foot allows for natural robotic walking and excessive torque and speed on the knee joint. It has the effect of mitigating.

       However, one-degree-of-freedom toe joints alone cannot satisfy a stable, natural pace on walking and irregular ground. Thus, a robot foot composed of a multi-degree of freedom platform can allow a smooth and effective body movement of the robot.

In addition, when implementing a step of the humanoid robot, when using a rotational driver such as a DC servo motor for the foot, excessive torque by the weight of the humanoid robot is required, and the use of a large power motor is difficult to structurally attach to the foot, On the other hand, if a large deceleration ratio is used, high speed steps cannot be generated, which causes difficulties in actual implementation.

       Therefore, when using a parallel mechanism that can generate a large rigidity with a small size can solve the above problems it is necessary to propose a new foot structure.

       Accordingly, the present invention is to solve such a conventional problem, the purpose of which is to configure the soles of the multi-platform so that the robot can walk similarly to humans in various ground environments, such as flat, stairs, slope, rotation, irregular ground In addition, the present invention provides a parallel instrumented multi-platform humanoid robot foot that can allow stable movement due to the generation of an efficient walking trajectory.

       Another object of the present invention is to provide a parallel mechanism-type multi-platform humanoid robot foot capable of supporting a large load by gravity and inertia of the robot by using a parallel mechanism portion that allows multi-axis movement of the sole.

       In addition, another object of the present invention is applicable to the artificial foot device of the disabled person without a foot in addition to the application of the humanoid robot foot, parallel mechanism-type multi-platform that can induce improved quality of life for people with a movement of the protective gear closer to human To provide a humanoid robot foot.

       The present invention to achieve the above object,

       Base:

       An intermediate platform having a parallel mechanism portion for positioning two active translational joints on the base to generate two degrees of freedom rotational motion;

       A front-left platform having a chain consisting of a serial joint including a 1 degree of freedom active translational joint fixed at an upper end on one front side of the base and connected to a lower end thereof;

      A front-right platform having a chain made of a serial joint including a 1 degree of freedom active translational joint fixed at an upper end on the other front side of the base and connected to a lower end thereof; And

       A rear-platform having a chain of serial joints including a 1 degree of freedom active translational joint fixed at the top of the base and connected to the bottom thereof; the front-left platform, the front-right platform and The back-platforms provide a parallel instrumented multi-platform humanoid robot foot, each rotatably connected to the intermediate platform.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

       Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

       Figure 1 shows the overall parallel instrumented multi-platform humanoid robot foot 1 according to the present invention, the front-left platform 12, the front-right platform 11, the intermediate platform 10, the rear-platform ( 14) and four platforms. Each of these platforms 12, 11, 10, and 14 is connected to the base 30 by a chain of joints to provide a total of five degrees of freedom.

       In FIG. 1, P means a translational joint, R means a rotational joint, U means a universal joint, and S means a ball joint. And underlined letters indicate active joints.

In addition, Pe means any one of the passive translation joint, Re means any one of the passive rotary joint, Pe means any one of an active translation joint such as an active translation joint (driver), for example a linear actuator. Re is an active rotary joint (driver), for example, any one of the active rotary drive to produce a roll angular movement or pitch angular movement.

       In addition, the symbols written in each of P, R, and U represent a specific portion of the front-left platform 12, the front-right platform 11, the intermediate platform 10, and the back-platform 14.

       (U1-R1), (U2-R2), (U3-R3) attached to the front-left platform 12, front-right platform 11, intermediate platform 10, rear-platform 14 in FIG. ), (U6-R4), (U4-R8) are the joints of the universal joint and the rotational joint, respectively, and serve as the ball joints (S).

In the present invention, as shown in Figure 1, three chains (U1-R1- P1 -U5) (U2-R2- P2 -U7) consisting of a series joint (S- Pe -Ue) of 6 degrees of freedom (U4-R) R8- P5- U8) are those that connect three platforms, such as the front-left platform 12, the front-right platform 11 and the rear-platform 14, to the base 30, respectively.

In the above ( P1 ) ( P2 ) ( P5 ) means the active translational joint of the front-left platform 12, the front-right platform 11 and the rear-platform 14, the active translational joint ( P1 ) Depending on the linear displacement value of ( P2 ) ( P5 ), the angle of rotation of each front-left platform 12, front-right platform 11 and rear-platform 14, ie the angle with respect to the intermediate platform 10, is changed. do.

That is, the active translation joints P1 , P2 , and P5 are respectively disposed between the base 30 and each platform 11, 12, 14, and each platform 11, 12, 14 and Active translational joints ( P1 ) ( P2 ) ( P5 ) are connected via the series joint (U1-R1) (U2-R2) (U4-U8) of the universal joint and the rotation joint, respectively. In addition, the base 30 and the active translation joint ( P1 ) ( P2 ) ( P5 ) are connected through the universal joint (U5), (U7) (U8).

       In addition, the front-left platform 12, the front-right platform 11, the rear-platform 14 is connected to the intermediate platform 10, respectively through the rotation joint (R9) (R10) (R11).

Accordingly, the relative angles of the front-left platform 12 and the front-right platforms 11 are changed according to the linear displacement values of the active translation joints P1 ( P2 ). Similarly, depending on the linear displacement of the active translational joint ( P5 ), the rear-platform 14 will have a different displacement with respect to the intermediate platform 10. In the above, the active translation joints P1 , P2 , and P5 may be linear actuators, for example.

In addition, as shown in FIG. 2, the intermediate platform 10 includes an intermediate chain ( Pe (Lm) -Re (φ) -R (θ)) consisting of three degrees of freedom joints, and an SS joint and a four-bar linkage. Two chains consisting of four-bar link chains U3-R3-R4-U6 connected by 21 are connected and connected to the base 30.

And the intermediate platform 10, as shown in Figure 2, two degrees of freedom parallel mechanism for generating translational and rotational motion through the active translation joint ( Pe (Lm)) and the active rotation joint ( Re (φ)) Due to the motion of 25 and the constraint of the four-bar link chain U3-R3-R4-U6 through the rotation of the four-bar link 21, the intermediate platform 10 has a rotational motion of two degrees of freedom (roll, Pitch).

The rotational motion of the two degrees of freedom parallel mechanism part 25 is generated independently according to the motion of two active translational joints P3 and P4 fixed to the base 30. This translational-rotating drive mechanism is mechanically equivalent to the active translational joint ( Pe (Lm))-active rotational joint ( Re (φ)).

The rotational motion of two degrees of freedom made in the intermediate platform 10 will be described in more detail with reference to FIG. 3. The active translation joints P3 and P4 are fixed to the base 30 to generate vertical motion, respectively, and the roll angle of the intermediate platform 10 according to the difference in the vertical heights of these active translation joints P3 and P4 . (φ) occurs.

In this case, two degrees of freedom parallel mechanism 25 is provided for the operation of the intermediate platform 10, in which the passive rotary joints R5 and R6 are opposite to the base 30 of the active translational joint P3 and P4 . Since the upper and lower heights of the active translation joints P3 and P4 are respectively inserted in the upper end, the positions of the passive rotary joints R5 and R6 are different.

The said manual rotary joint (R5) (R6), and the pitch of each connection portion 22 is the active prismatic joint respectively inserted a manual translational joint (P1) (P2) between the (P3), (P4) in order to compensate for this height difference It is to correspond to the position change of the manual rotary joint (R5) (R6) according to the height difference.

       In addition, the manual translation joint P3 is vertically connected to the base 30 so that the intermediate platform 10 generates only the vertical translation Lm and the roll angle φ. Connect the support 20.

This operating relationship is shown in FIG. 4. 4 schematically shows the joint arrangement of the two degrees of freedom parallel mechanism part 25. The two degrees of freedom parallel mechanism part 25 is provided with a manual translation joint P3 connected to the base 30 with two degrees of freedom support 20 and a manual rotation joint R7 at the bottom thereof to move up and down and rotate. Only possible. Therefore, the two degrees of freedom parallel mechanism part 25 allows the roll angle φ rotational movement in accordance with the vertical height difference of the active translational joint P3 ( P4 ). And the height of the intermediate platform 10 connected to the lower end of the two degrees of freedom parallel mechanism portion 25 is determined by the average height of the vertical translation of the active translation joint ( P3 ) ( P4 ).

       In addition, the two degree of freedom parallel mechanism portion 25 has a pitch angle connecting portion 22 positioned at the lower end of the two degree of freedom support 20 so that the pitch angle θ of the intermediate platform 10 can be rotated.

That is, the pitch angle connecting portion 22 is connected to the pitch angle (θ) movement with respect to the two degrees of freedom support 20, as shown in Figure 3, and consequently the intermediate platform 10 connected to the lower end thereof The pitch angle θ is caused to move. In this case, the intermediate platform 10 connected to the pitch angular connection 22 has a vertical translational motion Lm of the active translational joint P3 and P4 and a 4-position located at the front side of the intermediate platform 10. Pitch angular motion Re (θ) is generated by the constraint of the bar link chain U3-R3-R4-U6 (see Fig. 2).

As described above, the intermediate platform 10 has two chains ( Pe (Lm) -Re (φ) -R (θ)) and (U3-R3-R4-U6) to form an active translation joint ( P3 ) in parallel. ) (P4) and the vertical translation, the active prismatic joint (P3) (P4) and down a height difference, and the four-bar linkage chain (U3-R3-R4-U6 ) 2 free in accordance with the constraints of the rotational movement of the Fig. That is, the pitch angular motion Re (θ) and the roll angular motion Re (φ) are generated (see Fig. 4).

Fig. 5 shows each joint arrangement of the parallel instrumented multi-platform humanoid robot foot 1 according to the present invention. In other words, the front-left platform 11, the front-right platform 12 and the rear-platform 14 are each composed of a chain of six degrees of freedom (SPU) (U1-R1- P1 -U5) (U2). -R2- P2 -U7) (U4-R8- P5 -U8), the front-left platform 11, front-right platform 12 and rear-platforms 14 are the front of the intermediate platform 10 Or it is connected through the rotary joint (R9) (R10) (R11) from the rear, respectively.

       As a result, the final output displacement values of the front-left platform 11, the front-right platform 12 and the rear-platform 14 are the movements of the two degrees of freedom parallel mechanism part 25 of the intermediate platform 10, i.e. It is determined according to the pitch angular movement Re (θ) and the roll angular movement Re (φ).

       Therefore, the multiplatform robot foot 1 according to the present invention has a pitch angular movement Re (θ) and a roll angular movement Re (φ) of intermediate degrees 10 of the intermediate platform 10 as shown in FIG. 6. Each of the front-left, front-right, and back-platforms 11, 12, 14 relative to platform 10 will generate a total of five degrees of freedom movement of one degree of freedom relative rotational movement.

       As described above, in the present invention, the intermediate platform 10 generates two degrees of freedom movement of the humanoid robot ankle, that is, pitch angular movement Re (θ) and roll angular movement Re (φ), and rotates two degrees of freedom. When the relative motion of the front / middle platform other than the motion is the same, that is, when the pitch angle θ2 and the pitch angle θ3 are the same in FIG. 6, the motion of the metatarsal phalangal (MTP) joint of the foot is generated.

      In addition, the relative movement of the middle / rear-platform is when the pitch angle (θ4) is formed, which causes the relative movement of the hind feet when the robot lands during walking, and when the relative movements of the front-right and front-left platforms are different. That is, when the pitch angle θ2 and the pitch angle θ3 are different in FIG. 6, relative movement between the front-right and front-left platforms 11 and 12 may be generated during turning.

7 shows a link-joint relationship diagram of the humanoid robot foot 1 according to the invention. White boxes represent passive joints, diagonally filled boxes represent active joints, and lines between boxes represent links. It is possible to consider the translational-rotating form of two degrees of freedom parallel mechanism part 25 of FIG. 3 connected to the intermediate platform 10 from the point of view of motion and degrees of freedom as a series active joint Pe - Re , the following Grubler The formula can be used to define the motion of a given instrument part.

(1)

(One)

      (1) where d, n, g, and i represent the degrees of freedom of all joint spaces of a given instrument part, the number of links including the ground, the number of joint constraints, and the degrees of freedom of the i-th joint, respectively. Here the motion of the total 5 degrees of freedom of the four platforms is verified as follows.

       M5dof = 6 (13-16-1) + 1 × 8 + 2 × 3 + 3 × 5 = 5

If the rotary joint R11 and the chain U4-R8- P5- U8 connected to the back-platform 14 shown in FIG. 6 are separated from the intermediate platform 10, the degree of freedom of the final robot foot 1 is 4 as follows. Freedom.

       M4dof = 6 (10-12-1) + 1 × 6 + 2 × 2 + 3 × 4 = 4

Thus, the relative pitch angular movement relative to the intermediate platform 10 on the back platform to allow the S- Pe- S chain on the intermediate platform 10 to allow the heel strike on the front platform for toe purposes or like a human. It can be added or deleted so that it can be generated so that one platform can be modularized so that various types of movements of the soles and toes can be easily implemented.

Although the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited to such a specific structure. Those skilled in the art may variously modify or change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Nevertheless, it will be apparent that all such modifications or variations will fall within the scope of the present invention.

       As described above, according to the present invention, it is possible to generate a gait similar to a human walking normally, and by providing a multi-platform and parallel mechanism structure allowing an efficient gait, allowing relative movement of the sole to cope with various grounds, Through the use of a translational actuator, the effect of supporting large loads and impacts can be obtained.

       In addition, according to the present invention, the mobility of the humanoid robot can be improved by enabling the generation of a human-like walking trajectory, and the flexible foot movement is applied to the walking of the robot on flat, staircases, slopes, and irregular grounds, thereby greatly improving the stability of the entire robot. Can contribute.

       In addition, according to the present invention, in addition to the application of the humanoid robot foot can also be applied to the artificial foot device of the disabled without a foot, in this case, the movement of the protective gear is closer to the human is obtained an effect that can lead to the improvement of the quality of life of the disabled.

Claims (6)

       Base 30: An intermediate platform (10) having a parallel mechanism portion (25) in which two active translational joints ( P3 ) ( P4 ) are positioned on the base (30) to generate two degrees of freedom rotational motion; On the front one side of the base 30 is provided with a chain (U2-R2- P2 -U7) consisting of a series joint including a 1 degree of freedom active translational joint ( P2 ) fixed at the top, front-left connected to the bottom Platform 12; On the other front side of the base 30 is provided a chain (U1-R1- P1 -U5) consisting of a series of joints including a 1 degree of freedom active translational joint ( P1 ) fixed at the top, and connected to the bottom of the front-right Platform 11; And At the rear of the base 30 is provided a chain (U4-R8- P5- U8) consisting of a series joint comprising a 1 degree of freedom active translational joint ( P5 ) fixed at the top, and connected to the bottom of the back-platform ( 14); wherein the front-left platform 12, the front-right platform 11 and the rear-platform 14 are each rotatably connected to the intermediate platform 10, characterized in that Multi platform humanoid robot foot. 2. The four-bar link chain (U3-R3-R4-U6) according to claim 1, wherein the intermediate platform (10) is connected to the intermediate platform (10) and the two degrees of freedom parallel mechanism portion (25) generating translational and rotational motions. ), The two degrees of freedom parallel mechanism portion 25 has an intermediate chain consisting of three degrees of freedom serial joint, and the four-bar link chain (U3-R3-R4-U6) is an SS joint and four including the bar link 21, the two degree of freedom bottom of the active prismatic joint (P3), (P4) the vertical translational motion (Lm) and the active prismatic joint (P3) (P4) of having a parallel mechanism section 25 Parallel mechanism type multi-platform humanoid, characterized in that the pitch angular motion and the roll angular motion of the intermediate platform 10 is generated according to the height difference and the constraints of the 4-bar link chain U3-R3-R4-U6. Robot foot. 2. The intermediate platform (10) according to claim 1, wherein the intermediate platform (10) is in front of or behind the front-left platform (12), the front-right platform (11) and the rear-platform through the rotation joints (R9) (R10) (R11). And the front-left platform 12, the front-right platform 11, and the rear-platform 14 are connected to the intermediate platform 10 with the one degree of freedom active translational joint ( Parallel mechanism type multi-platform humanoid robot foot characterized by generating 1 degree of freedom relative pitch angular motion and varying relative degrees of freedom by the operation of P1 ) ( P2 ) ( P5 ). The front-left platform (12), the front-right platform (11) and the rear-platform (14) are chains (U1-R1- P1 -U5) consisting of six degrees of freedom joints (U2-). A parallel instrumented multi-platform humanoid robot foot, each having R2- P2 -U7) (U4-R8- P5 -U8). The front-left platform (12), the front-right platform (11) and the rear-platform (14) are universal joints (U1) (U2) (U4) and rotational joints (R1) (R2). (R8) is connected to each of the active translation joints ( P1 ) ( P2 ) ( P5 ) through a series coupling, the active translation joints ( P1 ) ( P2 ) ( P5 ) are universal joints (U5) (U7) ( Parallel instrument type multi-platform humanoid robot foot, characterized in that connected to the base (30) through U8). 2. The parallel instrumented multi-platform humanoid robot foot of claim 1, wherein the active translational joints ( P1 ) ( P2 ) ( P3 ) ( P4 ) ( P5 ) are each linear actuators.

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