WO2014003550A1

WO2014003550A1 - Walking mechanism for a robot, as well as a robot equipped with the walking mechanism

Info

Publication number: WO2014003550A1
Application number: PCT/NL2013/050451
Authority: WO
Inventors: Cyrill BREUKELAAR
Original assignee: Breukelaar Cyrill
Priority date: 2012-06-30
Filing date: 2013-06-25
Publication date: 2014-01-03
Also published as: NL2010078C2

Abstract

Walking mechanism for a robot, as well as a robot equipped with the walking mechanism walking mechanism (61) for a robot comprises two brackets (63, 65) each having two legs (67 - 73) which are rotatably connected to shoulder elements (83, 85). These shoulder elements are fitted to straight arms (87, 89) which are arranged at right angles to the shoulder elements. The free ends of the arms are connected to each other via a universal joint (9). The universal joint (91) comprises two U-shaped forks (93, 95) which are connected to each other via a cross of two shafts (97, 99) arranged at right angles to each other. The walking mechanism (61) is equipped with three motors for executing the necessary rotations for moving on. Motor (101) is capable of rotating the fork (93) around the shaft (97) of the cross. Motor (102) is capable of rotating the other fork (95) around the other shaft (97) of the cross. And motor (103) is capable of rotating the first bracket (63) around an imaginary axis (105) running parallel to the centre line of the first fork.

Description

Walking mechanism for a robot, as well as a robot equipped with the walking mechanism

DESCRIPTION:

Field of the invention

The invention relates to a walking mechanism for a robot comprising at two brackets. A robot further has a body to which the brackets are connected.

State of the art

A walking mechanism of this type is generally known. When applied to a robot the body of the robot is usually rigid and the brackets are rotatably connected to the body. A robot of this type walks in a typically robotic way.

Summary of the invention

It is an object of the invention to provide a walking mechanism for a robot by which the robot walks in a more natural way. For this purpose the walking mechanism according to the invention is characterized in that the brackets are connected to each other via a universal joint, which universal joint comprises two U-shaped forks which are connected to each other via a cross of two interconnected shafts arranged at right angles to to each other, where a first one of the forks is connected to one of the brackets close to the top of this bracket and rotatable around the centre line of the fork, and the other, second fork is connected close to the top of the other bracket but rigidly connected to this other bracket.

What is a striking phenomenon in most walking robots is the fact that the body is rigid despite the fact that in most living creatures the body moves during walking. A reason for this is that the legs are supposed to be mainly responsible for the walking movement and that the role of the body has little or no added value. However, the ability to walk requires slightly more than only moving the legs.

It is not the legs that are mainly responsible for the walking movement, but the body. Here lies the origin of the walking movement. The movement of the body is therefore of major importance during walking and cannot readily be disregarded for the construction of walking robots. A universal joint between the brackets can emulate the movement of the body.

An embodiment of the walking mechanism according to the invention is characterized in that close to the tops of the brackets arms are fitted that extend to each other from the brackets, where the free ends of the arms are connected to each other via the universal joint. The arms are preferably straight and are preferably arranged at right angles to the legs.

A further embodiment of the walking mechanism according to the invention is characterized in that the walking mechanism comprises at least three motors, of which a first motor can rotate one of the forks around one of the shafts of the cross, a second motor can rotate the other fork around the other shaft of the cross, and a third motor can rotate the first bracket around an imaginary axis parallel to the centre line of the first fork. When the motors are arranged in a similar fashion the walking movement can be executed.

A still further embodiment of the walking mechanism according to the invention is characterized in that each bracket comprises two feet which are positioned in a direction transverse to the direction of movement and spaced from each other. Each bracket preferably comprises two legs which each comprise one of the feet.

Yet a further embodiment of the walking mechanism according to the invention is characterized in that each leg is connected to a shoulder element close to the top end and rotatable around a shaft extending transversely to the direction of movement, to which shoulder element is fitted one of the arms, and the walking mechanism comprises further motors which can rotate the legs around the shafts. The shafts are preferably fitted to the legs and to the rotors of the further motors whose stators are fitted to the shoulder elements. As a result of this, a still better and more natural walking movement can be realized and the walking mechanism can move in a faster manner.

The invention also relates to a robot equipped with a walking mechanism according to the invention.

Furthermore the invention relates to a method of displacing a robot having two spaced-apart front legs and at a distance from them two spaced-apart rear legs, which front and rear legs each near their top end are connected to a front or rear shoulder element respectively, which shoulder elements are rotatable relative to each other around two shafts which are positioned at an angle relative to each other. With respect to the method the invention is characterized in that the method comprises the step of rotating either or both shoulder elements consecutively or at any rate partly simultaneously around a horizontal shaft arranged at right angles to the shoulder element, as a result of which one of the legs is lifted, and of rotating the shoulder element connected to the lifted leg at any rate partly simultaneously to this or after this around a vertical axis, in order to thus move the lifted leg forward.

With a robot comprising a universal joint having two forks which are rotatably connected to each other via a cross of two shafts arranged at right angles to each other, of which a first fork is rotatably connected to a first one of the shoulder elements and the second fork is fitted to the other, second shoulder element, the lifting of one of the legs is preferably effected by the simultaneous rotation of the first shoulder element relative to the first fork and the first fork relative to the second fork, so that these two rotate in unison around an imaginary line running through one of the feet connected to the first shoulder element and the intersection of the rotary shafts of the universal joint, as a result of which the other foot connected to the first shoulder element is lifted (cf. Fig. 4B).

Furthermore, with a robot of this type moving the lifted leg forward and the rear leg diametrically opposite is effected by rotating the second shoulder element and the second fork and the first shoulder element and the first fork relative to the cross and the feet of the two other legs, until gravity rotates the whole around an imaginary line running through the ground-based foot connected to the first shoulder element and the second- shoulder-element connected foot located diagonal to the ground-based foot, until the lifted foot connected to the first shoulder element reaches the ground while the other foot connected to the second shoulder element is lifted (cf. Fig. 4D).

For realizing a proper walking movement, subsequently preferably the second shoulder element and the first fork are rotated relative to the cross so that the lifted leg connected to the second shoulder element again touches the ground (cf. Fig. 4E).

Lifting one of the front legs is preferably effected by simultaneously rotating the first shoulder element relative to the first fork and the first fork relative to the second fork, so that the first shoulder element and the first fork rotate in unison around an imaginary line running through one of the feet connected to the first shoulder element and the intersection of the rotary shafts of the universal joint, as a result of which the other foot connected to the first shoulder element is lifted (cf. Fig. 4F).

Moving the lifted leg forward and the rear leg diagonally opposite is preferably effected by rotating the second shoulder element and the second fork and the first shoulder element and the first fork relative to the cross and the feet connected to the legs until gravity rotates the whole around an imaginary line running through the ground-based foot connected to the first shoulder element and the second- shoulder-element connected foot located diagonal to the ground-based foot until the lifted foot connected to the first shoulder element reaches the ground while the other foot connected to the second shoulder element is lifted (cf. Fig. 4H).

For finishing a complete cycle during the move, finally preferably the second shoulder element and the first fork are rotated relative to the cross and the first shoulder element relative to the first fork, so that the lifted leg connected to the second shoulder element touches the ground again (cf. Fig. 4A). After this the cycle can be repeated for carrying out a walking movement in this manner.

Brief description of the drawings

The invention will now be described in more detail hereinbelow based on examples of embodiment of the walking mechanism according to the invention while reference is made to the appended drawing figures, in which:

Fig. 1 shows a basic embodiment of the walking mechanism according to the invention without motors;

Fig. 2 shows a more extensive embodiment of the walking mechanism according to the invention;

Fig. 3 shows an extensive embodiment of the walking mechanism according to the invention comprising motors; and

Figs. 4A - 41 show various stages during a cycle of the walking movement according to the invention. Detailed description of the drawings

Fig. 1 shows a basic embodiment of the walking mechanism according to the invention. The walking mechanism 1 comprises two brackets 3 and 5 which are formed by rectangular plates. Straight arms 7 and 9 are fitted at right angles to the tops of the plates. The free ends of the arms are connected to each other via a universal joint 11.

The universal joint 11 comprises two U-shaped forks 13 and 15 which are connected to each other via a cross 17 of two shafts 19 and 21 perpendicularly arranged and connected to each other in the middle. One of the fortks 13 is rotatably connected to the arm 7 and the other fork 15 is rigidly fixed to the other arm 9. Each bracket 3, 5 has two feet 23 - 29 which are positioned spaced apart in a direction transverse to the direction of movement D.

Fig. 2 shows a more extensive embodiment of the walking mechanism according to the invention. Like components to those in the embodiment shown in Fig. 1 are labelled using the same references.

In this walking mechanism 31 the brackets 33 and 35 each have two legs 37 - 43 which are each rotatable around a shaft 45 - 51 and connected to a shoulder element 53, 55. These shoulder elements form part of the brackets and are fitted to the arms.

Fig. 3 shows an extensive embodiment of the walking mechanism according to the invention and which is equipped with motors. This walking mechanism 61 also has two brackets 63 and 65. Each bracket has two legs 67 - 73 which are each rotatable around a shaft 75 - 81 and connected to a shoulder element 83, 85. These shoulder elements form part of the brackets and are fitted to straight arms 87 and 89 which are positioned at right angles to the shoulder elements. The free ends of the arms are connected to each other via a universal joint 91.

The universal joint 91 comprises two U-shaped forks 93 and 95 which are connected together via a cross of two shafts 97 and 99 which are at right angles to each other and arranged together. This walking mechanism 61 is equipped with three motors 101, 102, 103 for executing the necessary rotations for the movements. A first motor 101 is capable of rotating the fork 93 around the shaft 97 of the cross. A second motor 102 is capable of rotating the other fork 95 around the other shaft 99 of the cross. And a third motor 103 is capable of rotating the first bracket 63 around an imaginary axis 105 running parallel to the centre line of the first fork.

The walking mechanism 61 further includes further motors 107 - 113 which are capable of rotating the legs 67 - 73 around the shafts 75 - 81. The rotors of the further motors are fitted to the legs and the stators are fitted to the shoulder elements.

The walking mechanism is further to be equipped with a control unit (not shown) connected to the motors, which causes the motors to make the proper rotations and tailors the rotations of the motors to each other so as to achieve a smooth walking movement. The walking mechanism is also to be equipped with an energy source (batteries) or a terminal for an energy source to be connected to.

Figs. 4 A to 4F give a clarification of a cycle of the walking movement according to the invention. Fig. 4A diagrammatically shows an embodiment of the walking mechanism for a robot according to the invention. Like components to those in the embodiment shown in Fig. 2 are labelled using the same references.

The walking mechanism has two spaced apart front legs 37, 39 and two spaced apart rear legs 41, 43 at a distance to them. The front and rear legs are each connected near their top ends to a front or rear shoulder element 53, 55 respectively. The shoulder elements are mutually rotatable around two shafts 19, 21 arranged at an angle to each other.

The walking mechanism further includes a universal joint 11 having two forks 13, 15 which are rotatably connected to each other via a cross 17 of two shafts 19, 21 arranged at right angles to each other. A first one 13 of these forks is rotatably connected to a first shoulder element 53 and the second fork 15 is fitted to the other, second shoulder element 55.

In a walking movement first of all one or both shoulder elements 53, 55 is consecutively or completely or partly simultaneously rotated around a horizontal shaft at right angles to the shoulder element, as a result of which one of the legs 39 is lifted. Subsequently, or completely or partly simultaneously to this action the shoulder element 53 connected to the lifted leg is rotated around a vertical axis to thus move the lifted leg 39 forward.

Lifting one of the legs 39 (cf. Fig. 4B) is effected by simultaneously rotating the first shoulder element 53 relative to the first fork 13 and the first fork relative to the second fork 15. This is to be effected such that the first shoulder element and the first fork together rotate around an imaginary line LI running through one of the feet 23 connected to the first shoulder element and the intersection of the rotating shafts of the universal joint 17. In consequence, the other foot 25 connected to the first shoulder element is lifted.

Moving the lifted leg 39 and the leg 41 forward (cf. Fig. 4C) is effected by rotating the second shoulder element 55 and the second fork 15 and the first shoulder element 53 and the first fork 13 relative to the cross 17 and the feet 23 and 29 until gravity rotates the whole around an imaginary line L2 (cf. Fig. 4D) running through the ground-based foot 23 connected to the first shoulder element and the foot 29 positioned diagonal to this and connected to the second shoulder element, until the lifted foot 25 connected to the first shoulder element reaches the ground. In consequence, the other foot 27 connected to the second shoulder element is lifted.

Subsequently, the second shoulder element 55 and the first fork 13 are rotated relative to the cross 17 around the imaginary line L3 running through the foot 29 and the cross 17 (cf. Fig. 4E), so that the lifted leg 41 connected to the second shoulder element again touches the ground.

Lifting one of the legs 37 (cf. Fig. 4F) is effected by simultaneous rotation of the first shoulder element 53 relative to the first fork 13 and the first fork relative to the second fork 15. This is to be effected such that the first shoulder element and the first fork rotate in unison around an imaginary line L4 running through one of the feet 25 connected to the first shoulder element and the intersection of the rotary shafts of the universal joint 17. As a result, the other foot 23 connected to the first shoulder element is lifted.

Moving the lifted leg 37 and the leg 43 forward (cf. Fig. 4G) is effected by rotating the second shoulder element 55 and the second fork 15 and the first shoulder element 53 and the first fork 13 relative to the cross 17 and foot 27 and foot 25 until gravity rotates the whole around an imaginary line L5 running through the ground-based foot 25 connected to the first shoulder element and the foot 27 connected to the second shoulder element and positioned diagonal to the ground-based foot, until the the lifted foot 23 connected to the first shoulder element touches the ground. During this action the other foot 29 connected to the second shoulder element is lifted as a result.

Finally, the second shoulder element 55 and the first fork 13 are rotated relative to the cross 17, and the first shoulder element 53 relative to the first fork 13, so that the lifted leg 43 connected to the second shoulder element touches the ground again. After this the walking mechanism has reached an initial state (cf. Fig. 41) from where it can repeat the process.

Albeit the invention described above has been described in the foregoing with reference to an example, it will be evident that the invention is not by any manner or means restricted thereto. The extent of the invention also extends to all embodiments deviating from the embodiment shown in the drawing figures within the scope defined by the appended claims.

Claims

CLAIMS:

1. A walking mechanism (1; 31; 61) for a robot comprising at least two brackets (3, 5; 33, 35; 63, 65), characterized in that the brackets (3, 5; 33, 35; 63, 65) are connected to each other via a universal joint (11; 22; 91), which universal joint (11; 22; 91) comprises two U-shaped forks (13, 15; 93, 95) which are connected to each other via a cross (17) of two interconnected shafts (19, 21; 97, 99) arranged at right angles to each other, where a first one of the forks (13; 93) is connected to one of the brackets (3; 33; 63) close to the top of this bracket and rotatable around the centre line of the fork, and the other, second fork (15; 95) is connected close to the top of the other bracket (5; 35; 65) but rigidly connected to this other bracket.

2. A walking mechanism (1; 31; 61) as claimed in claim 1, characterized in that close to the tops of the brackets (3, 5; 33, 35; 63, 65) arms (7, 9; 87; 89) are fitted that extend to each other from the brackets, where the free ends of the arms are connected to each other via the universal joint (11; 22; 91).

3. A walking mechanism (1; 31; 61) as claimed in claim 2, characterized in that the arms (7, 9; 87, 89) are straight.

4. A walking mechanism (1; 31; 61) as claimed in claim 3, characterized in that the arms (7, 9; 87, 89) are arranged at any rate substantially at right angles to the brackets (3, 5; 33, 35; 63, 65).

5. A walking mechanism (1; 31; 61) as claimed in any one of the preceding claims, characterized in that the walking mechanism (61) comprises at least three motors (101, 102, 103), of which a first motor (101) can rotate one of the forks (93) around one of the shafts (97) of the cross, a second motor (102) can rotate the other fork (95) around the other shaft (99) of the cross, and a third motor (103) can rotate the first bracket (63) around an imaginary axis (105) parallel to the centre line of the first fork.

6. A walking mechanism (1; 31; 61) as claimed in any one of the preceding claims, characterized in that each bracket (3, 5; 33, 35; 63, 65) comprises two feet (23, 25, 27, 29) which are positioned in a direction transverse to the direction of movement (D) and spaced from each other.

7. A walking mechanism (1; 31; 61) as claimed in claim 6, characterized in that each bracket (3, 5; 33, 35; 63, 65) comprises two legs (37, 39, 41, 43; 67, 69, 71, 73) which each comprise one of the feet (23, 25, 27, 29).

8. A walking mechanism (61) as claimed in claim 7, characterized in that each leg (67, 69, 71 , 73) is connected to a shoulder element (83, 85) close to the top end and rotatable around a shaft (75, 77, 79, 81) extending transversely to the direction of movement, to which shoulder element is fitted one of the arms (87, 89), and the walking mechanism (61) comprises further motors (107, 109, 111, 113) which can rotate the legs (67, 69, 71, 73) around the shafts (75, 77, 79, 81).

9. A walking mechanism (61) as claimed in claim 9, characterized in that the shafts (75, 77, 79, 81) are fitted to the legs (67, 69, 71, 73) and to the rotors of the further motors (107, 109, 111, 113) whose stators are fitted to the shoulder elements (83, 85).

10. A robot equipped with a walking mechanism (1; 31; 61) as claimed in any one of the preceding claims.

11. A method of displacing a robot having two spaced-apart front legs (37, 39) and at a distance from them two spaced-apart rear legs (41, 43), which front and rear legs each near their top end are connected to a front or rear shoulder element (53, 55) respectively, which shoulder elements are rotatable relative to each other around two shafts (19, 21) which are positioned at an angle relative to each other, characterized in that the method comprises the step of rotating either or both shoulder elements (53, 55) consecutively or at any rate partly simultaneously around a horizontal shaft at right angles to the shoulder element, as a result of which one of the legs (39) is lifted, and of rotating the shoulder element (53) connected to the lifted leg (39) at any rate partly simultaneously to this or after this around a vertical axis, in order thus move the lifted leg forward.

12. A method as claimed in claim 11, where the robot comprises a universal joint (11) having two forks (13, 15) which are rotatably connected to each other via a cross (17) of two shafts (19, 21) arranged at right angles to each other, of which a first fork (13) is rotatably connected to a first one of the shoulder elements (53) and the second fork (15) is fitted to the other, second shoulder element (55), characterized in that lifting one of the legs (39) is effected by the simultaneous rotation of the first shoulder element (53) relative to the first fork (13) and the first fork relative to the second fork (15), so that the first shoulder element and the first fork rotate in unison around an imaginary line (LI) running through one of the feet (23) connected to the first shoulder element and the intersection of the rotary shafts of the universal joint (17), as a result of which the other foot (25) connected to the first shoulder element is lifted.

13. A method as claimed in claim 11 or 12, characterized in that moving the lifted leg (39) forward and the rear leg (41) diametrically opposite is effected by rotating the second shoulder element (55) and the second fork (15) and the first shoulder element (53) and the first fork (13) relative to the cross (17) and the feet (23, 29) of the two other legs, until gravity rotates the whole around an imaginary line (L2) running through the ground- based foot (23) connected to the first shoulder element and the second- shoulder-element- connected foot (29) located diagonal to the ground-based foot, until the lifted foot (25) connected to the first shoulder element reaches the ground while the other foot (27) connected to the second shoulder element is lifted.

14. A method as claimed in claim 13, characterized in that subsequently the second shoulder element (55) and the first fork (13) are rotated relative to the cross (17) so that the lifted leg (41) connected to the second shoulder element again touches the ground.

15. A method as claimed in claim 14, characterized in that lifting one of the front legs (37) is effected by simultaneously rotating the first shoulder element (53) relative to the first fork (13) and the first fork relative to the second fork (15), so that the first shoulder element and the first fork rotate in unison around an imaginary line (L4) running through one of the feet (25) connected to the first shoulder element and the intersection of the rotary shafts of the universal joint (17), as a result of which the other foot (23) connected to the first shoulder element is lifted.

16. A method as claimed in claim 15, characterized in that moving the lifted leg

(37) forward and the rear leg (43) diametrically opposite is effected by rotating the second shoulder element (55) and the second fork (15) and the first shoulder element (53) and the first fork (13) relative to the cross (17) and the feet (25, 27) connected to the two legs until gravity rotates the whole around an imaginary line (L5) running through the ground-based foot (25) connected to the first shoulder element and the second-shoulder-element connected foot (27) located diagonal to the ground -based foot until the lifted foot (23) connected to the first shoulder element touches the ground while the other foot (29) connected to the second shoulder element is lifted.

17. A method as claimed in claim 16, characterized in that the second shoulder element (55) and the first fork (13) are rotated relative to the cross (17) and the first shoulder element (53) relative to the first fork (13), so that the lifted leg (43) connected to the second shoulder element touches the ground again.