JP2005144583A - Tetrapodal traveling machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tetrapodal traveling machine for realizing a moving shape such as a gallop, a trot, a pace and a bound (a jump) with a further simple mechanism. <P>SOLUTION: This tetrapodal traveling machine 1 having the whole legs making walking figure motion including a floating phase separating from the ground surface, can change a relative position of a body part, a front leg part and a rear leg part between the body part 5, the front leg part 2 and the rear leg part 3, and is provided with a joint part 4 having a rotatable node on both ends. The vertical movement of the center of gravity in the floating phase, is reduced by rotating the joint part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a four-leg running machine that performs four-leg running.

  Currently, most robots are for industrial use, and are specialized in certain parts of the human motor functions. For example, an arm robot that performs metal welding or attaches parts to a manufacturing machine is well known, and has become a very common robot in the industry.

  With the miniaturization of computers, the development of IC technology, and the emergence of various sensors, robots are becoming more humanized and animalized. Humanization and animalization are robots that mimic humans and animals rather than robots that have exactly the same form and function as humans and animals. For example, the robot is a biped robot that is the same as a human, or a robot that walks on four legs, such as a dog or a cat. Also, by giving emotions to robots (expressing emotions with anger when tapped and delighted when stroked), toys that appear to be like pets have also appeared.

  Some moving means use wheels. In all trains, cars, bicycles, etc., the rotational movement of the wheels is changed to the movement movement of the car body such as a straight line, curve, or circle. The movement of the vehicle body by wheels is not suitable for moving on uneven surfaces such as depressions and stairs or on the floor. In this respect, biped walking and quadruped walking of animals are highly adaptable to floors with steps such as stairs. It is human desire to make robots realize the same form as humans and animals (especially walking and running). Of course, it is also a desire to realize a robot that enables movement methods and actions that cannot be moved by wheels.

  When a person walks, put your right foot forward and at the same time swing your right hand back and your left hand forward. That is, the right foot and left hand, and the left foot and right hand move in the same direction. If you become crawl on all fours and move the limbs as they are, you will be walking a quadruped animal. The action of walking is an action of moving with either foot on the ground. Even when a quadruped animal runs, it is basically an extension of the movement of walking. In the case of a horse, the left and right of the front legs or the left and right legs of the rear legs may be temporarily aligned in the aerial posture during competition, but the right and left legs are separate when landing. This is the same during take-off and works separately on the left and right. It is not a movement to jump together with both feet, which is said to be jumping.

  As an invention that deals with a moving device by walking on four legs, there is a “four-legged traveling device” (Patent Document 1). In the present invention, the front left and right legs and the rear left and right legs are connected to the operation part of the approximately five-bar linkage mechanism, and each operation part is operated in series by one drive source (one actuator). A gait similar to a leg animal is possible. In addition, by making the left and right legs narrow, it has a structure that allows the same steering method as a bicycle or motorbike.

  As an invention of a legged mobile robot that performs a violent motion such as running or dynamism without using a large drive mechanism having a high operating speed and a large torque, there is a “legged mobile robot” (Patent Document 2). In addition to a normal drive mechanism such as an actuator that performs walking motion, it is equipped with a power storage mechanism composed of a mainspring, flywheel, etc., enabling instantaneous operation by releasing the stored power instantaneously Yes.

  As an invention of a legged mobile robot that performs various legged motions such as crawling, bounces, gallops, and trots, there is a “legged mobile robot and leg mounting structure” (Patent Document 3). By attaching a coil spring between the body part and the upper leg part, a force larger than the driving force of the actuator is obtained, and an operation requiring an instantaneous force such as a sway is possible. Moreover, the impact force at the time of landing is relieved by the spring. By mounting an upper link and a lower link that can rotate around the connection part of the body part in parallel to the body part and the base of the leg part, the rotational movement is changed to the vertical movement of the leg part, so that walking and running are possible. It is possible. At this time, a lateral blur occurs due to the rotation of the link, but by making the length of each link sufficiently longer than the width of the vertical movement, the lateral blur can be ignored.

  In “Robot Device and Jump Control Method of Robot Device” (Patent Document 4), legs of a four-point link mechanism (four-bar link mechanism) are employed. The ends of the two connecting rods (link rods) constituting the four-point link mechanism in the body direction are connected by a rotation support shaft, and the other end is connected to a connecting member (a part that becomes a knee joint). The connecting member is connected to a rod having a coil spring and a leg (rod-like member) connected to the foot. A contact sensor is attached to the tip of the rod-like member that becomes the foot, and it can be determined whether the foot is floating or is landing by the signal of the contact sensor. In addition, sensory functions similar to those of humans are reproduced by analyzing signals from touch sensors, distance sensors, microphones, CCDs, etc. using integrated circuits. In particular, it is noted that the expression of emotions by learning function is also adopted as part of the robot motion. The rotational movement of the rotary spindle is converted into a linear movement of the rod-like member by a four-point link mechanism. In addition, by using a servo motor as the driving force, it is possible to rotate freely according to the command of the control unit, and various gaits and operations are drawn out. When the robot touches the ground, the joint bends and the coil spring contracts. Therefore, as the next operation, the rod is pushed down by the elastic force in the extending direction of the coil spring, the joint (connecting member portion) is extended, and a jumping operation can be performed. This reduces the load on the servo motor.

Although used in the above example, the four-bar linkage is applied in various forms in robotics. In the above, it is described as “4-point link mechanism”. FIG. 1 shows an example of a four-joint link mechanism, and at least one joint is often fixed to a base portion. In the example of FIG. 1, when the link AB is linked to the drive unit at the node A and rotates, the length of the link bar has a relation of AB <BC <CD <AD and the link bar AB is θ ₁ degree. If the link rod CD is rotated by θ ₂ degrees by rotating, the relationship θ ₁ > θ ₂ is established. That is, it can be used when moving a large object with a small force.

FIG. 2 is an example of a four-bar linkage mechanism having a Chebyshev first approximate linear motion mechanism. It is assumed that the points A and D are fixed, and the point B can rotate around the point A. Further, when the point E on the extension of the link bar BC is assumed, the following relational expression holds.
AD = 2AB
BC = CD = CE = 2.5AB
When the point B moves circularly under this condition, a part of the locus of the point E becomes an approximate straight line as shown in the figure. This is called Chebyshev's first approximate linear motion mechanism, and is used as a legged walking mechanism of the robot.

JP-A-9-132119 JP 2001-246585 A JP 2002-103253 A JP 2003-80477 A

  In the current quadruped traveling machine (robot), the movement form (gait) is basically uniform. This is because it is difficult to freely switch the link form of the mechanical structure and reflect it in the moving form. However, the robot apparatus mentioned in the prior art can move, stop and jump. This is realized by a control device, an energy storage mechanism (using elastic energy of the material <mainly spring>), a link mechanism, a servo motor, and the like.

  The problem to be solved by the present invention is to realize a four-leg traveling machine that realizes a movement form such as gallop, trot, pace, and bound (jump) with a simpler mechanism. In terms of horse racing, gallop means assault (how to run during competition), trot means fast walking, and pace means the flow of the race, but here it is used to mean running, walking, stride (or speed), etc. In particular, it aims at a quadruped running machine that can run fast.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a quadruped running machine that performs a gait motion including a floating phase in which all legs are separated from the ground, and between the trunk part, the front leg part, and the rear leg part. The four-leg traveling machine is characterized in that a joint portion having pivotable nodes is provided at both ends to change the relative positions of the body portion, the front leg portion and the rear leg portion.

  By rotating the joint connecting portion, the body portion moves in the direction of lowering relative to the front leg portion and the rear leg portion in the floating phase, so that the vertical movement of the center of gravity is reduced.

  There is a method of jumping high as a way to gain time in the floating phase. But jumping high requires a lot of power and is inefficient. Therefore, in the present invention, a pivotable joint portion is provided at the portion corresponding to the spine to suppress the change in the height of the center of gravity, and as a result, it is possible to gain time for the floating phase without jumping high. Yes, you can move quickly.

  In the floating phase where all of the legs are off the ground, a large amount of power is required to resist gravity. Therefore, by keeping the height of the center of gravity of the entire machine constant by rotating the node connecting the joint part, the front leg part and the rear leg part with the movement of the legs so that less energy is required, A gait movement with a long floating phase can be realized.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 3 is an assembly model of the four-leg traveling machine of the present invention. FIG. 4 is an illustration of an example of the machine of the present invention in the floating phase. In the four-leg traveling machine 1 of the present invention, a front leg portion 2 and a rear leg portion 3 are connected to a body portion 5 via a joint portion 4 so as to be rotatable.

FIG. 5 shows a basic way of walking for a quadruped walking animal. Solid lines Lfl and Lbl are the left leg (front side when viewed from the side) and broken lines Lfr and Lbr right leg (the back side when viewed from the side). The operation of walking is as follows.
(1) Still state. At this time, the four legs are in a grounded state (more precisely, the sole is in a grounded state).
(2) Start walking. Bend left front leg Lfl and right rear leg Lbr and move them forward. At this time, the right front leg Lfr and the left rear leg Lbl are in contact with each other and generate a force to push the body Bd forward.
(3) The state where the left front leg and the right rear leg are in contact with each other and the entire weight has moved.
(4) The left front leg and the right rear leg are in contact with the ground, and the right front leg and the left rear leg start to move.
(5) The right front leg and the left rear leg are in contact with the ground and the entire weight has moved.

  In this way, the basic motion of a four-legged walking animal is an operation in which a leg (leg) on a diagonal line is grounded to generate a propulsive force, and a leg on another diagonal line is floated and moved forward. The fact that the diagonal legs are in contact with the ground means that the body can be stabilized because the center of gravity of the body is on the diagonal line. Running is basically an extension of walking. The difference is that the movement of the four legs moving away from the ground at the same time is added. In the case of a quadruped machine, if the kicking power of the grounding leg (kicking leg) is increased, the whole body (four legs) will naturally float away from the ground. In order to realize the above operation, the movement of the front leg and the rear leg may be reversed.

  FIG. 6 is a continuous view showing the gallop state of the machine of the embodiment shown in FIG. It turns out that the fluctuation | variation of the height of the gravity center position at the time of driving | running | working is small because a front leg part and a rear leg part rotate in a joint part.

  The quadruped traveling machine of the present invention is a moving body that enables high-speed traveling on rough terrain.

It is explanatory drawing of a four-bar linkage mechanism. It is explanatory drawing of Chebyshev's 1st approximate linear motion mechanism in a four-bar linkage mechanism. It is an assembly model of the quadruped running machine of the present invention. It is explanatory drawing of an example of the machine of this invention in a floating phase. It is a figure for demonstrating the basic way of walking of a quadruped walking animal. FIG. 5 is a continuous diagram showing a gallop state of the machine of the embodiment shown in FIG. 4.

Explanation of symbols

1 Four-leg traveling machine 2 Front leg 3 Rear leg 4 Joint part 5 Body part

Claims (1)

In a quadruped running machine that performs a gait motion including a floating phase in which all legs are separated from the ground, the relative positions of the trunk, front legs, and rear legs between the trunk, front legs, and rear legs A four-legged running machine characterized in that a joint part having a rotatable node is provided at both ends to change the position.