JPH07237154A - Leg walking robot - Google Patents

Abstract

PURPOSE:To exceptionally heighten static stability, and simplify, lighten and downsize a function by setting the leg number to the specific number in a mechanism to move by legs having joints like a mammalian animal, a reptile or an insect. CONSTITUTION:Four support legs 7 to 10 are arranged to a single idle leg 6, and the leg number is set to five, and they are controlled so that a center gravity position 11 enters the inside of a quadrangle created by these legs at walking time with an always sufficient allowance, and walking is made possible while maintaining a stable attitude. In the case where legs are set in five in this way, even when two legs are swung up, when these are not adjacent to each other, a stable attitude can be similarly secured by residual three legs. In such a robot, since roll joints are arranged close to the roots of the respective legs, an action to facilitate direction change is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel that has been widely used in the past for moving or transporting, for example, floors with unevenness, steps, pipes and other laying, or stairs in factories. In an environment where it is impossible or difficult to enter, by stepping on multiple legs in an order suitable for that environment and walking, even in an environment where the wheels cannot advance further, The possibility of fulfilling the function can be increased. As a result, it is possible to contribute to automation of transportation and inspection work of various articles and expansion of the range of disaster prevention / security work.

[0002]

2. Description of the Related Art Conventionally, for example, transportation and transfer of materials and products have been important tasks in factories, and various human-driven vehicles and unmanned transport robots guided by signals have been used. Has been. Since these use wheels as a means for supporting and moving, they can be used only in a relatively flat environment where the wheels can move. The crawler is effective on slightly uneven ground, but since it tramples all the places where it passes, it cannot be used where there is a laying that is troubled by the weight. Unrelated to the condition of the floor is the crane, which can only be used in that area because its equipment is fixed to the building. In recent years, a walking mechanism using jointed legs has been studied as a means for avoiding such restrictions. As for what has been specifically announced,
There are monopods, bipods, tripods, tetrapods, and hexapods. Of these, one, two, and three tripods are mainly for the purpose of moving the mechanism themselves, and are not suitable for carrying other materials. Although the four legs have the same number of legs as many animals, it is difficult to control the balance or stability of the posture when the monopod is lifted for movement, and there are functional limitations. On the other hand, the hexapod has high stability, but the number of legs is large, and the mechanism tends to be complicated, the weight is heavy, and the hexapod tends to be an obstacle.

[0003]

As described above, the wheels,
A legged robot with joints may be effective in an environment where crawlers and cranes are not used, but this legged robot still has many problems at present. Among the robots that have been published so far, mono- and biped robots are unstable even when standing, and their movements also require dynamic control, making them unsuitable for carrying other goods. It doesn't. The same is true for a tripod robot, which becomes unstable when one or two legs are raised for movement.
A four-legged robot can be made stable even if it swings up a monopod, but it is quite difficult to take a large stability margin in a quiet walk where no dynamic force is exerted, and the center of gravity is three. Care must be taken in stride lengths, deep bends in certain leg joints, and movement so that the landing points of the supporting legs do not become unstable outside the surrounding triangular area. For this reason, there are defects that the moving speed does not become too high and that the posture cannot always be kept horizontal. The horse's trot, dynamic walking such as pace and bounce can maintain a stable state as a whole, but other defects such as vibration of the main body and impact on the floor occur.

Therefore, as a legged robot having a practical joint, it is important that the robot be statically walked and statically stable. In this respect, a six-legged robot is easy to maintain stability even when walking quietly, but since it has many legs, it tends to be a hindrance and is inefficient in terms of occupied area and volume, and the mechanism is complicated accordingly. , Increase weight and energy consumption.
That is, there is a dilemma that the number of legs is preferably large in order to increase stability during walking, but is small in terms of mechanism, weight, energy and the like.

[0005]

In order to achieve the above object, the present invention uses a joint structure and a five-leg structure together. In other words, by using five legs with joints, it is possible to maintain stability not only in one leg but also in three legs when swinging up to two legs in static walking. If it is arranged, its stability margin can be secured much larger than that of the four-legged case. Moreover, since the number of legs is less than that of a hexapod, it is superior to the hexapod robot in many points such as occupied space, mechanism, weight and energy consumption.

[0006] Taking advantage of such an advantage, if a roll joint is arranged near the base of each leg, it is easy to change the direction in which the entire traveling direction is changed, and if a linear joint is provided, the slope or stairs can be changed. Even in such an environment, the posture of the body can be easily controlled.

[0007]

[Action] By setting the number of legs to five in the leg walking robot, it is possible to obtain the action of allowing a large stability margin even during static walking. FIG. 1 is a plan view showing a typical example in which the number of legs is four and the number of legs is five. In the case of a four-legged vehicle, as shown in FIG. 1 (a), when one leg is stepped out to move forward and the tip of the leg becomes a free leg (1) separated from the ground, the load is not supported. 3 support legs (2, 3,
And 4). In a typical example in which the load is evenly distributed over the entire body, the position of the center of gravity (5) rides right above the side of the triangle formed by the three support legs, so the so-called stability margin is 0, and this robot is Whether it falls or not, it is at the border. Therefore, by changing the position of each support leg a little, the position of the center of gravity (5)
Must be accommodated sufficiently, or the knee joint of each supporting leg must be bent so that the projected position of the center of gravity also falls within the triangle, but this is not so easy.

In the case of five legs, however, in FIG. 1 (b), there are, for example, four support legs (7, 8, 9, and 10) for one free leg (6), which are made by them. The position (11) of the center of gravity enters the quadrilateral with a sufficient margin, and is stable as it is. Further, as shown in FIG. 1 (c), even if the two legs are swung up to make the two free legs (12 and 13), three support legs (14, It is also an effective action of this leg walking robot that stability can be secured in 15 and 16).

Further, by providing a roll joint near the base of each leg in such a robot, an action of facilitating direction change can be obtained. Further, in such a robot, by providing a linear joint in each leg, the posture of the body can be easily controlled, and an effective action can be obtained, for example, when going up and down an inclined surface or stairs. This is also an effect obtained because the stability is largely secured by the joint structure and the five legs being used together.

[0010]

EXAMPLES Examples will be described with reference to the drawings.
Figure 2 shows the pitch joint (17) and roll joint (1
FIG. 8) is a side view showing an arrangement example of the linear motion joint (19). The number and arrangement order of each joint can be appropriately designed according to the required degree of freedom and the like.

FIG. 3 is a typical example of straight advancement, which is an example of trying to walk to the right in the figure.

FIG. 4 shows a case in which the user is going to change the direction from the rightward direction to the near side of the drawing. The front leg is made to be a free leg and the roll shaft is operated to change the direction toward the near side and step out. It is showing the place.

FIG. 5 shows an example of walking on an inclined surface, especially stairs.
The linear axes of the two lowest support legs are extended to keep the body in a horizontal position.

As shown in FIGS. 3, 4 and 5, 1
Stability is easily secured even if two legs or two legs become free legs. Therefore, by using the roll axis and linear motion axis together, it is easier to change direction or walk on an inclined surface. It becomes easier to realize a walking robot. Furthermore, one or two legs that have become free legs can be used to perform work other than supporting the body, for example, pushing other objects.

[0015]

Since the present invention is constructed as described above, it has the following effects.

By using the joint structure and the five legs together,
The static stability can be significantly increased compared to the case of 4 or less, and the number of legs is 1 compared to the 6-legged one which has been announced as a mechanism with high stability so far. Since it is small, it also has the effects of simplifying the mechanism, reducing weight, space and energy consumption.

This also facilitates the combined use of roll joints and linear joints for each leg, and has the effect of facilitating direction changes and walking on inclined surfaces.

Furthermore, the one or two legs that are free legs also have the effect of being able to appropriately perform work other than supporting the body.

[Brief description of drawings]

FIG. 1 is a plan view showing that the five-legged type has a larger static stability margin than the four-legged type.

FIG. 2 is a side view showing an example of arrangement of pitch joints, roll joints, and linear motion joints in the embodiment.

FIG. 3 is a three-dimensional view showing an example of walking to the right in the drawing in the example.

FIG. 4 is a perspective view showing an example of a case where the direction is changed from the right side of the drawing to the front side of the drawing.

FIG. 5 is a three-dimensional view showing an example of walking on stairs.

[Explanation of symbols]

 1 Free leg in case of four legs 2 Same support leg 3 Same support leg 4 Same support leg 5 Position of center of gravity when load is evenly distributed 6 Free leg 7 in case of 5 legs 7 Same support leg 8 Same support leg 9 The same support leg 10 The same support leg 11 The position of the center of gravity when the load is evenly distributed 12 The free leg 13 for five legs 13 The other free leg 14 The same support leg 15 The same support leg 16 The same support leg 17 Pitch Joint 18 Roll joint 19 Linear joint

Claims (3)

[Claims] 1. A legged walking robot, such as mammals, reptiles and insects, which has five legs in a mechanism for moving by legs having joints. 2. A legged walking robot having five legs, each leg having one or more pitch joints,
In addition, if necessary, one or more roll joints or one or more linear joints are included, and the roll joints at the relatively upper part of the leg can be used to easily change the direction, or the pitch or linear joints A leg walking robot that can control the posture such as keeping the body horizontal even on surfaces and stairs. 3. A leg walking robot in which at least three of the five legs can stably support the body by itself, and the remaining one or two legs can appropriately perform work other than supporting the body.