JP2005103725A - Stably walking method, step controlling method and steering method of leg-type robot and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leg-typed walking robot walking, steering or turning in an arbitrary direction without laterally swinging its trunk while reducing vertical movement of a platform wherever on a flat ground, a slope and an irregular ground, offsetting standing torque by platform load, and keeping a seat horizontal with a chair mounted on the platform. <P>SOLUTION: The walking robot consists of arms R1 and R2 rotating around a hip joint shaft C and legs L1 and L2 pivoted to the tips of the arms. A cam E is coupled to the hip joint shaft C and the vertical movement of a roller 7 following an outline of the cam is transmitted to the platform 5, thereby keeping a constant height of the platform 5 from the ground 4. On the slope, a phase between the shaft C and the cam E is changed by a cam rotational angle phase shifter 9 to stabilize the height of the platform 5 from the slope 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention makes it possible to prevent the vertical movement of the loading platform, to change the stride, to steer and turn at any angle, which has been difficult in legged walking robots that continuously rotate the hip joint, and to perform pitching and yawing (yaw). ), And a method and means for moving a person or an object on flat ground, sloping ground, and rough terrain with reduced rolling (roll). In particular, the present invention relates to a walking technique that enables stable movement and steering in special environments such as gravel roads and mountain roads with many bumps, river beds, shallows, swamps, sandy land and slippery snowy roads.

  At sites where natural disasters such as earthquakes, typhoons, fires, landslides, and other human disasters occur, priority is given to saving lives and preventing the spread of disasters. In cities with many slopes, there is a need for transportation means that does not burden people. A walking vehicle useful for such a field is required to freely change the stride and the traveling direction as needed, and enter the destination without being disturbed by obstacles such as scattered debris. In particular, in the rescue of human life, the cargo bed needs to remain calm without being affected by the disturbance of the scaffold.

  The present invention makes it easy to get over obstacles steadily while suppressing the vertical movement of the loading platform with respect to the ground, change the direction of travel if necessary, or turn on the spot to enter the target location. To. In disaster scenes that are dangerous for humans, mobility is enhanced by walking and steering by wireless control.

  In addition, the present invention uses existing visual sensors and distance sensors in combination to change stride and course by detecting the approach to a groove such as a waterway, not just a protrusion, and rides up, steps down, kicks , Allowing you to walk without waking up. For example, a gap between a platform and a train that serves as a wheelchair barrier can be made barrier-free by the device of the present invention. Even if there is a step there is no problem.

  In raising and lowering home stairs, etc., the stride is automatically adjusted to match the tread interval at that time, and the worry of stepping off the legs is eliminated. Carry your baggage gently without shaking. In addition, it turns around on the landing and changes direction greatly, enabling intermittent turns and up and down stairs.

  Such a capability is effective for commercialization and commercialization of legged walking robots for wheelchairs, or materials transportation robots for rough terrain such as snowy roads, gravel roads, and shallows, and human mobile robots. For this reason, the present invention greatly benefits the development of the vehicle industry that moves on rough terrain and the welfare equipment industry for an aging society.

Various mechanisms and devices related to the legged walking method have been developed so far as a moving method suitable for stepping over steps. For example, there are a multi-joint type such as a biological foot, a crawler type that is not seen in a living organism, and a vertical movement type. However, since these control the legs individually, the pitch, yaw, and roll of the robot body are generated, making walking unstable. Further, it has not yet been possible to keep the fuselage horizontal or reduce the vertical movement of the fuselage. For this reason, the sense of equilibrium of the rider or the animal is disturbed, and in the case of goods, cargo collapse is caused and it is difficult to say that it is a stable moving means.
JP 2002-308159 A Japanese Patent No. 1599141 Yoneda, Funakubo, "Current Status and Issues of Wheelchair / Walking Assistance Device" Journal of the Robotics Society of Japan, Vol. 11, No. 5, pp. 644-648, 1993

  The crawler type is effective for improving the running stability. As an example, there is a stair climbing vehicle for wheelchairs, for example, JP-A-2002-308159. However, these are generally complex structures because of the need to deform the crawler track.

  On the other hand, a simple method has been devised in which a fixed-length arm is continuously rotated around the waist and both the kicking and stepping motions are realized simultaneously with the legs pivotally supported by the arm tips (leg-type running method) And its device, Japanese Patent Application 2002-211286). This method and apparatus are effective for crossing obstacles on the ground or moving up and down stairs with a small number of actuators.

  This device uniquely determines the landing position of the leg without changing the stride. For this reason, even if there is a stone or a groove in the front, it will be forcibly stepped on and will walk without being disturbed by some obstacles. Taking measures to prevent cargo collapse will help to transport goods. However, since the legs are climbed on obstacles or submerged in depressions, the unevenness of the ground makes people and animals uncomfortable.

  Even in robots that are optimally designed according to the size of the stairs at the design stage, in the case of long stairs, the position of the landing landing on the tread surface is gradually shifted due to the influence of accumulated disturbance, and the landing rhythm is eventually destroyed. Falls into an unstable gait. To correct the direction of travel in the middle of walking, the rotational speeds of the left and right hip joints are different, which causes pitch, yaw, and roll, making the robot's posture unstable.

  In addition, since the base of the leg rotates, there is a characteristic that the load is moved up and down. This characteristic not only reduces the efficiency of energy use, but also makes the rider uncomfortable. Furthermore, when walking is stopped in the middle, it is necessary to continue to apply a self-supporting torque to the hip joint axis to maintain the arm posture at that time. For this reason, even when the robot is stopped, it is necessary to output extra energy that is not related to movement by the motor.

  A displacement corresponding to the vertical movement of the robot body is generated in the reverse direction using the rotational movement of the hip joint, and this cancels the vertical movement displacement of the loading platform. That is, the loading platform is separated from the hip joint, and the upward movement due to the arm rotation is canceled by the downward movement generated separately by the same arm. For this reason, an axisymmetric cam having a predetermined angle with respect to the extending direction of the arm is fixed to the rotation shaft of the hip joint. Further, a roller for fixing the shaft to the loading platform is made to follow the cam from the hip joint shaft. By this method, the roller is lowered by the amount that the hip joint is raised, or the roller is raised by the amount that the hip joint is lowered, so that the height of the loading platform from the ground is kept constant and the vertical movement is eliminated.

  The cam means that the load on the platform is transmitted to the hip joint shaft via a roller. The hip joint torque due to this load acts in a direction to cancel out the self-supporting torque of the robot received from the ground. As a result, the energy given to the motor to make the robot independent can be reduced. By this effect, the present invention automatically cancels the self-supporting torque by the load on the platform. Moreover, the conventional unstable walk is solved by such means.

  Furthermore, the present invention pays attention to the fact that the legs do not always have to be vertical if the legs can support the load, and the walking speed is changed by changing the left and right leg steps uniformly, or the left and right steps are changed in the reverse direction. Steer. This point is also a new means and contributes to solving the conventional problems.

  The robot is equipped with a tilt angle sensor and automatically detects the angle at which the body tilts with respect to the horizontal. This is generally equal to the ground inclination angle θs, and this situation is assumed in the following description. Further, the continuous rotation angle θa of the arm around the hip joint axis is detected. Further, the value of the leg deflection angle γ when the arm is horizontal is input as command information from the operator. Then, the posture angle of the leg with respect to the rotation angle θa of the arm is calculated by an arithmetic unit and output to the servo mechanism to be incorporated.

  The present invention can be applied to a robot having a plurality of hip joints, but in the following, for the purpose of simplifying the explanation of the entire mechanism of the robot, one hip joint is provided on each of the front part and the rear part, and each hip joint has the same number of arms. It shall be equipped with legs (2 or 3). In addition, the suspension mechanism necessary for each leg can be easily realized by existing technology, so that it will be omitted in the following description.

  In short, the present invention takes the following means. (1) An axially symmetric cam is fixed to the hip joint, and the loading platform is supported by the shaft of a roller guided above the hip joint axis by a long hole while rolling on the cam. (2) Increase the stride angle by opening the leg to the outside and increasing the stride, and closing it inward to decrease the stride. (3) Change the walking speed without changing the arm rotation speed by uniformly changing the stride of the left and right legs. (4) Change the stride by controlling one of the left and right legs to open outward and the other to close inward, and change the direction of walking while keeping the torso horizontal. (5) Turn on the spot while keeping the torso of the left and right legs and rotating the left and right hip joint axes in opposite directions to keep the body horizontal. (6) As an instruction from the operator, walking is realized by selectively inputting a leg deflection angle, a distinction between outer opening and inner closing, a direction and speed of hip joint axis rotation, and a leg posture angle pattern. (7) Realize stable walking and steering of the robot using a total of four actuators, two for left and right hip joint drive and two for leg posture control. In walking on a sloping ground, one actuator is added for controlling the posture of the roller guide slotted plate and one for controlling the cam mounting angle.

  In the present situation where it is difficult to develop a bipedal walking robot that carries people and luggage on the back, the method and apparatus of the present invention, such as stepping stones, stairs, pedestrian bridges, etc. suitable for biped walking made by nature, or biped walking made by humans, Providing technology that makes the environment movable with four legs. In particular, there is an advantage that step length control can be added to the basic movements of stepping and kicking up by floating a cylindrical shaft concentrically on the hip joint axis and floating it separately from the hip joint. Also. Reducing the number of rotation axes has the advantage of simplifying the motion mechanism and reducing the number of parts required to generate leg motion. Further, by synchronizing the four legs, the number of motors required for movement is reduced, and the control is simplified.

  In slope residential areas nationwide, there are many elderly and disabled people who have difficulty moving, so they need a means of transportation that allows them to ride with peace of mind. However, in reality, there are no easy-to-use means, effective measures cannot be found, and it is difficult to go to hospital, go out, and even shop for everyday life. In particular, Nagasaki City with many slopes, which is said to be a slope city, has set up a tilt monorail and a tilt elevator with the cooperation of citizen volunteer organizations to solve the problem.

  However, these are public orbital outdoor transportation means and do not provide a transportation means around the house or indoors. On the other hand, the present invention provides a stable walking means that crosses over an obstacle on an irregular ground and avoids / detours by reducing vertical movement regardless of whether it is indoors or outdoors, and whether there are stairs or stone steps. provide.

  For example, the stride can be easily adjusted by increasing or decreasing the stride before the step, or the stride initially specified in the artificial regular staircase can be fine-adjusted while moving up or down, or the step can be stepped on an irregular staircase such as a mountain path. Provide technology such as landing at a certain distance from the wall. In addition, various embodiments are possible for rough terrain. One example is the movement between the platform and the train already mentioned. The present invention, which only needs to leave small footprints intermittently, can be considered as an embodiment as a moving means for carrying out farming work without damaging the fields.

  Pitch, yaw, and roll that occur in the robot body are phenomena peculiar to legged robots, but the technique of the present invention has an advantage of eliminating these by using a cam and synchronously driving the legs. In addition, the rotation angle of the hip joint is taken into account, and the stride is changed by slightly changing the leg direction. In addition, the tilt angle sensor and servo mechanism are used to suppress the vertical movement of the cargo bed with respect to the ground, regardless of whether it is flat or sloping, so that the passengers who are walking do not feel anxiety or fear.

  On flat ground, the direction of travel is controlled to be large or small by changing one of the left and right legs to open outward, the other to close inward, and the size of opening and closing. Furthermore, the left and right hip joint axes are reversed to enable a large change of direction and turn on the spot.

  If the visual sensor informs you of obstacles in front of walking or the danger of a leg collision with a step, it will be properly steered or the stride will be changed to avoid an accident such as a collision or stepping off.

  FIG. 1 shows a hip joint mechanism of a walking robot having a cam E as Embodiment 1 of the present invention. Two arms R1 and R2 extend in the opposite directions from the hip joint axis C, and the legs L1 and L2 are pivotally supported by the knee joints J1 and J2 of each arm tip. However, in the simplest configuration, power transmission means S1, S2 such as sprockets placed coaxially with the hip joint and power transmission means S1 ', S2' such as sprockets fixed to the base of each leg are The power transmission means B1 and B2 are coupled respectively.

  The radii of S1 and S1 ′ and S2 and S2 ′ are equal, and when S1 and S2 are fixed to the robot body 1, the legs always face a specific direction, for example, the vertical direction regardless of the rotation angle of the arm. FIG. 2 shows the movement of the arm and leg in this case as a line drawing. However, in the figure, the case where the arm is rotated in steps of 20 degrees while keeping the hip joint in the same position is viewed from the hip joint axis direction.

  If the legs and hip joints that move as described above are arranged at the four corners of the robot and symmetrically in the front-rear and left-right directions, the side appearance of the robot standing on a flat ground is as shown in FIG. However, the motor and power transmission means are omitted from the figure (hereinafter the same). Although it is a three-dimensional structure with four hip joints, the left and right sides overlap and appear to be a planar structure. The elongated frame indicates the robot body 1, the both ends thereof indicate the hip joint axis C, and the center indicates the center position G.

  The robot is most stable when landing on four legs (8 legs in total). FIG. 4 shows a state where the arm is rotated from this state and is walked to the right. It can be seen from the figure that while one leg of the arm tip extending in the opposite direction is landed, the other is rotating as a free leg and then landed and replaced with the previous landing leg. However, for ease of viewing, the depiction is stopped before landing again.

  The alternate landing movement of each leg moves the robot center position G at the same time as kicking up the ground. The step length Q is equal to the interval 2r between the knee joints J1 and J2. Hereinafter, the postures of the legs parallel to each other at any position as in this walking are referred to as a standard posture, and the stride at that time is referred to as a standard value.

  The left and right hip joints rotate synchronously in phase in the same direction or in opposite directions, so no yaw or roll occurs in the walking robot. However, a pitch is generated. That is, G is repeatedly displaced up and down during the walking process (G, G ′, G ″,... In FIG. 4). This up and down movement occurs regardless of the level or the slope.

  In the present invention, a cam is coupled to the hip joint shaft in order to eliminate this vertical movement. In particular, in a flat ground walking robot, the structure is simplified by fixing the cam directly to the hip joint axis. That is E in FIG. This cam E takes the form of two peaks (a) and three peaks (b) in FIG. (a) and (b) also show how the cam is fixed to the hip joint axis. The reason for maximizing the cam radius in the direction in which the arm extends and maximizing in the direction in which the arm does not extend is to recover the amount of descent of the cargo bed caused by the rotation of the arm. The shape seen from the side is like an airplane propeller.

  The cam rolls the roller 7 on the hip joint shaft (see FIG. 1). In addition, the shaft is guided by a long hole on the side plate of the robot body 1 and fixed to the loading platform 5 to move it up and down. As a result, the vertical movement opposite to the vertical movement of the hip joint is generated by the cam, and the height of the loading platform 5 from the landing is changed. If this height is always at the top, the maximum cam radius is generally equal to the length of the arm.

  Specifically, the difference between the maximum radius and the minimum radius of the cam is determined to be the arm length. A cam mechanism for shortening the cam radius compared to the arm in consideration of the strength of the cam and the radius of the roller is also realized by using various known displacement enlarging mechanisms.

  FIG. 6 explains in detail the operation related to the first embodiment of FIG. In particular, the situation of cam and roller action at different rotation angles of the arm is shown from above and from the side. In both cases, the case where the hip joint rotates several tens of degrees in the clockwise direction is shown on the left, and the case where the hip joint is rotated further is shown on the right. The situation when the arm is horizontal and vertical is shown in FIG. However, the left side is horizontal, the right side is vertical, the side is up, and the front is down. H is a link that integrates the left and right roller shaft guide slots. From these figures, it is clear that the loading platform 5 maintains almost the same height from the ground even if the robot body 1 moves up and down.

  Furthermore, the roller 7 on the shaft fixed to the loading platform 5 presses the cam downward with the loading of the loading platform. Therefore, a load torque (Tc in FIG. 6) is generated on the hip joint axis C. On the other hand, the hip joint axis C receives a self-supporting torque (TL in FIG. 6) from the ground to support the robot. The torques Tc and TL act in opposite directions and cancel each other.

  This can be said at any hip rotation angle. The cam shape in the figure is the result of such a design. In addition, Tc and TL increase or decrease in the same manner according to the load on the loading platform. Due to such a relationship, the power of the motor that must be supplied for independence even during a stop is automatically canceled by the load torque, and energy supplied to the motor from the outside is saved.

  FIG. 8 shows a second embodiment of the present invention. That is, a change in leg posture for changing the stride is shown. This is realized by relatively changing the mounting angle of the hip joint side sprocket to the robot body according to the rotation angle of the hip joint. From this figure, the increase in the stride Q is clear.

  FIG. 9 shows a third embodiment of the present invention in which the stride Q is made small. It can be seen from both figures that the stride can be freely changed by simply controlling the leg posture. This changing method is described in detail below because it relates to the tilt angle of the robot body. In Examples 2 and 3 in which the stride is changed, the front and rear hip joint axes rotate synchronously to keep the body 1 always horizontal, but are displaced up and down every half rotation. In fact, the torso 1 is set to the lowest position when the arm is horizontal and to the highest position when the arm is vertical (see FIG. 7). If the opening and closing angles of the legs are the same, the vertical displacement width is the same for both the katakana “ha” shape of FIG. 8 and the “so” shape of FIG. The walking with these up and down movements gives discomfort to the rider as in FIG. For this reason, the present invention is equipped with a cam that rotates integrally with the arm, follows the roller, and supports the loading platform by the shaft of the roller.

  That is, the cargo bed is separated from the fuselage and always kept at the highest level. Therefore, the roller is raised when the arm is horizontal, and lowered when the arm is vertical. FIG. 10 shows a walking state of the second and third embodiments including the cam and roller and the loading platform.

  In the figure, E is a cam, and 7 is a roller guided by the elongated hole to follow the cam above the crotch axis C. The shaft of the roller 7 is fixed to the loading platform 5, presses the roller downward by the load, and positions the loading platform at a height determined by the shape of the cam.

  In particular, for walking on flat ground, there is an advantage that the propeller-shaped cam E can be mechanically fixed to the arm. As a result, the vertical movement width V1 of the body 1 becomes approximately the arm length (= R1 = R2), whereas the vertical movement width V2 of the loading platform 5 becomes extremely narrow (see FIG. 10).

  Further, in this figure, the mechanical facts explained in FIG. 6 are just as effective. That is, the load acting on the loading platform rotates the hip joint axis C in the clockwise direction via the roller and the cam. On the other hand, when the hip joint C is self-supporting in the situation shown in FIG. Since these directions are opposite to each other, the hip joint torque necessary for self-supporting is automatically subtracted by the load acting on the loading platform. As a result, the driving energy of the motor can be reduced.

  The flat ground walking robot of FIG. 10 shows that it is stable even at different strides, but when entering the slope as it is, the position of the center of gravity shifts to the valley side and the tilt becomes unstable. In order to eliminate this instability, the present invention detects the ground oblique angle θs and controls the posture angle of the leg using this and the arm rotation angle θa. By this control, the state of FIG. 11 is automatically realized. Each part of the robot transitions as shown in FIG.

  Here, it should be noted that a cam that is fixed to the arm is not useful for walking on a sloping ground. This is because the robot body tilts, and not only can the vertical movement of the loading platform be eliminated, but also the self-supporting torque cannot be compensated. In order to solve this problem, according to the present invention, the angle of attachment of the cam to the hip joint axis is determined semi-fixed based on the output of the computing unit 10 using the arm rotation angle and the ground inclination angle measured during walking.

  That is, as in the fourth embodiment of the present invention in FIG. 13, the gear U1 is fixed to the hip joint shaft, and the gear U2 is meshed therewith. Then, the gear U3 integrated on the same shaft as U2 is meshed so as to be inscribed in the outer frame inner gear U4. This mechanism is similar to the planetary gear mechanism in which U1 is a sun gear, U2 and U3 axes are planetary axes, and U4 is an internal gear, but it is special in that the planetary gears are composed of U2 and U3.

  The planetary axis Je on the three outer circumferences of the hip joint axis C forms a planet carrier 8 that rotates concentrically with the hip joint axis. Further, the cam E is fixed to the outer frame of the internal gear U4. The gear U1 is used as an input shaft, the planet carrier 8 is fixed, and the internal gear U4 is used as an output shaft. The planet carrier 8 is fixed on a flat ground, but is used for adjustment to deviate the angle of the output shaft relative to the input shaft when the ground is inclined. In this sense, it is semi-fixed.

  In order to explain this, the planetary carrier 8 in the figure is provided with a lever 6. The present invention is not limited to this, and other means such as a gear and a belt may be used. FIG. 14 shows an external appearance sketch of Example 4 that employs the cam rotation angle phase shifter 9 of FIG.

  Note that the angle at which the planetary carrier 8 is deflected is an output θd from a calculator to be described later. However, since the pitch circle radii of the gears U1, U2, U3, U4 are r1, r2, r3, r4 and r1 · r3 = r2 · r4, the cams coincide with the rotational speed of the arm and rotate in opposite directions. Therefore, the mounting angle is changed as shown in FIGS. 10 to 15 by utilizing the axial symmetry of the cam. The biggest reason why the planetary gear is composed of U2 and U3 is that the rotation amounts of C and E are the same. Further, by doing so, the planetary carrier 8 is deflected by half of the angle θd so that the cam mounting angle can be changed to the specified angle θd.

  Eventually, the computing unit 10 outputs half (θd / 2) of the cam mounting eccentric angle determined according to the tilt of the robot body detected from the sensor, and responds to the tilt angle of the ground using a servo mechanism not shown. The cam mounting angle θd to the arm is realized.

  Since FIG. 10 is for flat ground, it is possible to mechanically fix the cam to the arm as in FIG. 5, but on an oblique ground, the cam is tilted by the angle of the arm when all legs (8 legs) land. It is necessary to deviate and bond to the arm. For this reason, Example 4 of FIG. 13 is adopted.

  As a result, the vertical movement width V2 of the loading platform can be made extremely small even when walking on slopes, and the self-supporting torque can be compensated by the load torque. However, it is necessary to construct a four-joint parallel link mechanism with the two long sides facing the front and back of the long hole plate that guides the roller, and always use the oblique angle θs to position the long hole direction directly above the hip joint axis. is there. Since such a mechanism is realized by a known technique, description thereof is omitted. The position of the roller 7 in FIG. 15 indicates the situation obtained in this way.

  As in FIG. 10, it is clear that the vertical movement width V1 of the loading platform 5 is narrowed while the vertical movement width V1 of the robot body 1 is large. At the same time, the load of the loading platform 5 is transmitted to the hip joint axis C via the cam. This is the same even when the stride is changed as shown in FIGS. However, the illustration in this case is omitted.

  Next, step length control and steering control will be described in detail. For explanation, as shown in FIG. 16, the relative deflection angle θc of the sprocket (S1, S2) with respect to the trunk is determined using the arm rotation angle θa, the trunk inclination angle θs, and the leg posture angle θb. However, the angles θa, θs, θb, and θc in the figure are based on the front of the body, the horizontal plane, or the vertical plane, and the arrow direction is positive. θa is an angle measured using a rotary encoder, θs is an inclination sensor, and the like.

  The input / output information related to the arithmetic unit 10 necessary in the present invention is shown in FIG. However, the function f1 is the leg posture angle θb, the function f2 is θc (= θs−θb) when the number of arms extending from the hip joint is 2, the function f3 is θa−θs, and the function f3 is the cam mounting angle. The eccentric angle θd of the change lever 6 is determined. This is an input to a servo mechanism (not shown) that changes the mounting angle of the cam without leading to a special device. In particular, it is indispensable when walking on slopes stably. When the leg deflection angle γ and the identifier i of the posture angle pattern Pi are specified in addition to θa and θs, the functions f1, f2, and f3 are actually calculated. However, it is assumed that the step opening and closing is determined by the difference in the sign of γ, and the step length is determined by the difference in value.

  Note that θa increases or decreases with the number of rotations of the arm, and the arithmetic unit 10 always replaces it with 0 & ltθa & lt2π. Furthermore, every time θa increases by π radians, the arithmetic unit 10 adds the current stride, and every time π radians decrease, decreases the stride at that time, and determines the accumulated value as a movement distance from the walking start point. The function f1 must be a periodic function of θa, and is generally limited to the following four.

(Equation 1)
θb = γcos {θa−θs}
(Equation 2)
θb = γsin {2 (θa−θs)}
(Equation 3)
θb = γcos {3 (θa−θs)}
(Equation 4)
θb = tan-1 {(tanγcos (θa−θs)) / (1 + tanγsin (θa−θs))}

  Assuming that the four patterns represented by the above formulas 1, 2, 3, and 4 are P1, P2, P3, and P4, respectively, these are represented by a, b, c, and d in FIG. The figure of the slip also shows the leg posture when the arm rotates around the hip joint axis C by 20 degrees. However, the right indicates outward opening (0 <γ), and the left indicates inward closing (γ <0). The pattern when the function f1 defines θb = 0 irrespective of θa is shown in FIG. 2, and the stride is a standard value.

  In the four types of patterns in FIG. 18, the amount of the inner closing and the outer opening of the legs associated with each other is the same. For this reason, the corresponding left and right legs position the hip joint at the same height from the ground. This is the principle and advantage of the steering method of the present invention in which one of the left and right legs is controlled to open outward and the other is controlled to close inward to keep the robot body horizontal. As described above, the function f1 is calculated one by one in the arithmetic unit 10 by applying a trigonometric function to γ and (θa−θs), and the output is θb. If numerical processing is performed without relying on algebraic expressions, patterns other than the four examples a to d can be uniquely determined.

  Although it is conceivable to create such a pattern by following the contour using a cam instead of the computing unit 10, the stride and the steering angle cannot be flexibly changed as necessary. For this reason, the generation of the walking pattern by the cam is virtually meaningless.

  In the upper part of FIG. 19, the above pattern P2 is used, and a robot with an equal length (assumed to be 40 cm) of arms and legs is set to γ = + 20 degrees (from the left to the right) on an oblique ground with an angle of 30 degrees (large stride) (Embodiment 5) The embodiment 5 of the present invention is ascending with a small step). The calculated step length is Qmax = 96 cm. However, the step length when γ = 0 is a standard value of 80 cm.

  Similarly, the lower part of FIG. 19 employs the pattern P2 described above, and a robot having an isometric arm (for example, 40 cm) and an arm and a leg having an angle of 30 degrees from left to right γ = −20 degrees ( Embodiment 6 of the present invention rising with a small step) will be described. The calculated stride is Qmin = 68cm.

  In order not to make the knee joint collide with the step when the stairs are raised or lowered, it is desirable that the leg tip precedes the knee, and the choice of the posture angle pattern is meaningful. As such candidates, the right in patterns a and b in FIG. 18 and the right in pattern d are recommended. That is, the outward opening by the patterns P1 and P2 and the outward opening walking by the pattern P4 are effective. Which of patterns P1 to P4 is selected depends on the application of the robot. In order to avoid sudden changes in walking motion, it is necessary to match the timing for changing the leg opening / closing and the amount of opening / closing, that is, the leg deflection angle γ and posture angle pattern Pi, to the timing when the arm is vertical. desirable.

  The loading platform 5 can mount a sitting chair as a leg walking chair. In this case, the seat is required to remain horizontal regardless of the inclination of the ground. For this reason, in the present invention, as shown in FIG. 20, an axis Jc parallel to the hip joint axis is placed on the front side of the loading platform 5 separately from the roller axis as shown in FIG. FIG. 21 shows Example 7 when viewed from the top. However, this figure shows a state where the right leg is steered forward and the right leg is shaped like a letter S and the left leg is shaped like a letter C.

  On flat ground, the cam E can be fixed to the arm as shown on the left in FIG. 20, but on sloping ground the cam E is attached to the robot body via the cam rotation angle phase shifter 9 as shown on the right. Is changed according to the oblique angle θs. In this case, the torque Tc acting on the hip joint axis appears in the same direction as the self-supporting torque TL, but is reversed in the inside because of the cam rotation angle phase shifter 9, and the load torque compensates the self-supporting torque. It will not change.

  The link H is necessary for positioning the front and rear roller shaft guiding slot holes on the hip joint shaft even in sloping ground. This constitutes one side of the four-node parallel link mechanism having four nodes at both ends and the front and rear hip joint axes. Then, based on the ground inclination angle θs input from the sensor, the link mechanism is changed to a different quadrilateral using a servo mechanism (not shown), and the elongated hole is directed right above the hip joint.

  The tilt angle θs is simultaneously used for controlling the tilt angle of the rotation axis Jc of the seat by another servo mechanism. As a result, the seat surface of the seat 11 is leveled to prevent the passenger 12 from sliding down. It is also possible to apply a bias signal to the servomechanism and control the seat chair upward so that the occupant can always hang deeply on the chair. The reason for placing the axis Jc on the front side of the loading platform is to eliminate the psychological fear given to the passengers in consideration of the general usage pattern in which the line of sight is directed to the valley side.

  Furthermore, the present invention enables steering during walking by rotating one of the left and right leg strides outwardly and closing the other inward to rotate the left and right hip joints in the same direction. On flat ground, the left and right leg strides are unified to either open or closed, and the left and right hip joints are rotated in the opposite direction to enable in-situ turning. In addition, the step size to be unified is changed, and the turning angle is arbitrarily set.

  FIG. 22 shows this turning from above. It can be seen that the four landing legs slide on the ground with the rotation of the hip joint and turn the robot to the right. In addition, the black circle in a figure shows the projection point on the ground of a landing leg. The arm at the moment of becoming vertical loses its apparent length.

  FIG. 23 shows a stride control device for controlling the sprockets S1 and S2 to + θc and −θc when the number of arms is 2 as the eighth embodiment of the present invention. That is, while the legs are always in the vertical posture in FIG. 1, the sprockets S1 and S2 are pivotally supported on the hip joint axis, and the mounting angle with respect to the robot body is swung in the range of + θc and −θc. Indicates a device that automatically creates a figure-shaped or S-shaped leg posture.

  The main shaft of the bevel gear is controlled to the output θc (= θs−θb) of the function f2 by the servo mechanism, and the rotation angle of the two driven gears meshed with this is connected to the other end of the double cylindrical shaft that is coaxial with the hip joint. Tell. Sprockets S1 and S2 are fixed at each end, and the angles are controlled synchronously to + θc and −θc, respectively.

  This mechanism makes it easy to create the various patterns shown in FIG. The main shaft rotation angle of the bevel gear is measured by a potentiometer and used as a feedback signal for the servo mechanism. The bevel gear is characterized in that it swings forward and backward and does not rotate continuously.

  FIG. 24 shows a stride control device in the case of the arm number 3 as the ninth embodiment of the present invention. Also in this case, the same number of sprockets S1, S2, and S3 as the arms are arranged on the same hip joint axis. In addition, a cylindrical shaft fixed to each of the three swing rods that swing while being guided by the rotation shaft of the crank mechanism is mounted on the same hip joint shaft in triplicate. Each shaft connects the corresponding three sprockets and rocking rods in order.

  The crank mechanism is arranged at a place where the movement of the belt or the like meshing with the sprocket is not hindered, and the driving shaft thereof is controlled by the dedicated actuator to the output θc (= θa−θs) of the function f2 of the calculator 10.

  Although the rotation of the crankshaft is continuous, the motion of the swing rod is a reciprocating motion, so that the three sprockets have a swing motion. FIG. 25 illustrates the detailed connection between the hip joint axis and the crank mechanism as viewed from the hip joint axis direction. From the figure, it can be seen that the three cylindrical shafts always oscillate sequentially without disturbing the phase due to the movement of the three crankshafts synchronized with the rotation of the hip joint shaft.

  24 and 25, D indicates the distance between the hip joint shaft and the crank mechanism drive shaft. This distance governs the maximum deflection angle of sprockets S1, S2, and S3, and is used for stride length control. That is, the distance D is reduced to realize the outward opening of the leg, and the distance D is increased to achieve the inner closing control. Thereby, the pattern P4 can be easily generated. The distance D is uniquely related according to the output θb of the function f1 of the computing unit 10, and can be controlled by a known technique.

  FIG. 26 shows an overview of the apparatus 13 for inputting commands necessary for steering walking and turning walking in an easily understandable manner as the tenth embodiment. It is composed of a control stick and an operation panel. The operation panel is regarded as a walking robot, and the head of the control stick is tilted in the traveling direction, and the force to be tilted is adjusted according to the walking speed. Rotation around the control stick gives information to command turning motion. Switch W on the operation panel selects and switches the type of posture angle pattern. The adjacent rotary knob inputs the leg deflection angle γ. For example, + (external opening) on the right,-(internal closing) on the left, and γ = 0 are input on the intermediate scale.

  The embodiment has been described above with reference to the drawings. Motors, batteries, belts, gears, sprockets, shaft support means, cams, displacement expansion mechanisms, tilt angle sensors, potentiometers and their signal processing circuits, servo mechanisms that control to specified angles, bevel gear mechanisms, crank mechanisms, A device for changing the distance between the rotating shafts can be found in a commercially available product or specially processed and easily procured.

  In short, the present invention eliminates the vertical movement of the loading platform, which was a drawback of the legged walking robot, and at the same time compensates the self-supporting torque with the load torque of the loading platform, saves driving energy and stably transports the load. Further, the leg is controlled to the posture specified by the computing unit 10 to change the stride, so that the bumps are crossed over the bumps to avoid the collision with the obstacle and the falling into the groove. Alternatively, a technique is provided in which one of the left and right legs is controlled to open outward and the other is controlled to close inward, and the direction of travel is continuously changed while the robot body is kept horizontal to bypass obstacles.

  In the stairs, the stride is adjusted to the tread interval peculiar to the stairs, and the leg is landed at the center of the tread to avoid collision with the stepped wall and to eliminate the stepping off. On flat ground, technologies are provided such that the left and right hip joint axes are reversed while the left and right leg strides are the same, and the robot turns on the spot.

  In the leg-type walking robot, the rotational torque necessary for self-supporting is compensated by the load on the loading platform to reduce the supply energy to the hip joint drive motor, and the loading platform is separated from the robot body, and the cam is coupled to the arm. The vertical movement width of the loading platform is reduced by supporting the roller shaft to follow. Furthermore, the present invention provides a method and apparatus for controlling the stride of left and right legs to change the course in an arbitrary direction, or turning on the spot with the rotation directions of the left and right hip joints reversed.

  The method and apparatus of the present invention is useful for detouring to avoid collisions with obstacles encountered during walking on rough terrain. Further, it is effective to avoid the legs that are moving up and down the stairs from colliding with the stepped wall or removing the tread. For this reason, we provide new technologies not only for new development of indoor and outdoor rough moving vehicles, but also for the development of legged walking chairs that can lift and lower stairs that serve as wheelchair barriers. What contributes to the development of

Example of cam arrangement that helps to eliminate vertical movement during walking (Example 1) Synchronized arm and leg movement with hip rotation Walking robot that stands on flat ground Trajectory of trunk, arms, and legs when walking on flat ground Cam contour and fixed angle to the arm (left when arm number is 2 and right when arm is 3) Cam operation of the first embodiment Principle of canceling the vertical movement of the cargo bed of Example 1 Example 2) Trajectory of walking on a flat ground with outer legs Trajectory of walking on flat ground with inner closed legs (Example 3) Dissolving body vertical movement and self-supporting torque compensation in Examples 2 and 3 A walking robot that stands on a sloping ground taking into account the slant angle θs Transition of torso, arms and legs when walking on sloping ground Cam mounting angle changing mechanism (Example 4) External appearance sketch of Example 4 Effect of cam to eliminate up / down movement of bed even in sloping ground Definition of angle variables Input / output information of arithmetic unit Various types of leg opening (right figure) and inner closing (left figure) (a, b, c, d correspond to posture angle patterns P1, P2, P3, P4) Body and arm and leg motion trajectories when walking on sloping ground with posture angle pattern P2, upper open walking (Example 5), lower closed walking (Example 6) Seat chair attached to the carrier (Example 7) Example 8 seen from above In-situ turning motion A bevel gear mechanism for leg posture angle control when the number of arms is 2 (Example 9) Crank mechanism for leg posture angle control when arm number is 3 (Example 10) Example 9 seen from the axial direction Device for inputting robot walking commands (Example 10)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leg type walking robot body 2 Bevel gear mechanism 3 Crank mechanism 4 Ground, flat ground, sloping ground, stairs, etc. 5 Loading platform 6 Cam mounting angle changing lever 7 Cam contour copying roller 8 Planet carrier 9 Cam rotation angle phase shifter
10 Calculator
11 seats
12 Passengers
13 Walking command input device r Arm length, gear radius
B Timing belt or chain
C Hip axis
D Distance between hip joint axis and crank drive axis
E-cam
F Operating force (Fx for left / right direction component, Fy for front / rear direction component)
G Robot body center position
H Long hole plate connection link for left / right or front / rear roller shaft guide
J knee joint
Jc seat rotation axis
Je planetary axis
L leg
M hip drive motor
Q stride length
R arm
S Hip side gear or sprocket
S 'Knee joint gear or sprocket
T rotational force, rotational torque
U gear
V Robot body and vertical movement width of loading platform
W Posture angle pattern selection switch θa Hip joint rotation angle θb Leg posture angle θc Deflection angle of sprocket S θs Ground inclination angle (including stairs)
θd Cam mounting deviation angle to the robot body γ Leg deflection angle when the arm is horizontal (leg posture angle in general)

Claims (12)

  In a walking robot having a leg as a leg pivotally supported by an arm tip that rotates continuously around a hip joint, a cam is coupled to the hip joint shaft, and the roller is guided through a slot provided in a hip joint upper side plate of the robot body. And the rotation axis of the roller is fixed to the loading platform to keep the loading platform height constant with respect to the ground, and at the same time, the hip joint torque necessary for the robot to stand on its own with the loading load including the loading platform. A stable walking method for a legged robot, which compensates for this, thereby eliminating the vertical movement of the loading platform and reducing the drive energy of the hip joint.   The walking robot according to claim 1, wherein the posture angle of the leg (= θb) is expressed by an arithmetic unit using the tilt angle (= θs) of the robot body relative to the gravity direction and the rotation angle of the arm (= θa). The function f (θs, θa) is defined as a periodic function of θa, that is, f (θs, θa) = f (θs, θa + 2nπ) to ensure the continuity of the leg posture change and further extend in opposite directions. Satisfy the condition to control one armtip leg to lean forward and the other to lean backward, that is, f (θs, θa) + f (θs, θa + π) = 0 A stride control method for a legged robot characterized in that the stride forward and backward can be changed by controlling to close or open outward.   With respect to the stride according to claim 2, by setting one of the left and right legs to be outwardly open, the other to be inwardly closed, and equally defining the angular width of the outwardly open and inwardly closed, all hip joints are synchronously driven in the same direction. A legged robot steering method characterized in that the robot body can be moved in an arbitrary direction without being tilted left and right while keeping the robot body horizontal.   3. In claim 2, the left and right hip joints are synchronously driven in the opposite directions to perform in-situ turning at an angle depending on the stride, or in claim 3, the left and right hip joints are synchronously rotated in the opposite directions. A steering method for a legged robot, characterized in that the turning motion and movement at an angle depending on the stride can be realized.   In the hip joint, an axisymmetric cam that is fixed to the arm, a roller that rolls on the outer periphery of the cam, and a long hole on the side of the robot body that supports the lower part of the side of the loading platform and allows the roller to reciprocate above the hip joint axis. A stable walking device that implements the walking method according to claim 1.   6. The walking device according to claim 5, further comprising a servo mechanism for changing a cam mounting angle in a semi-fixed manner in accordance with an output from a computing unit, and canceling the vertical movement of the loading platform with respect to the ground even when walking on a slope. A stable walking device characterized in that the driving energy of the vehicle is reduced.   A bevel gear mechanism, and a servo control mechanism that determines the main driving shaft of the bevel gear as an output value (= θs−θb) of the bevel gear when the number of arms mounted on one hip joint is two and the arms extend in opposite directions; The method according to claim 2, 3 or 4, further comprising: a cylindrical shaft arranged in a double manner on the hip joint shaft for the purpose of transmitting the reverse rotational movement of the opposite driven shaft of the bevel gear as a change in leg posture. Equipment that realizes   When the number of arms to be equipped in one hip joint is 3 and the arms extend in the direction of equally dividing the circle, a cylindrical shaft arranged in three on the hip joint axis, a ring fixed to one end of each cylindrical shaft, and parallel to the hip joint axis A three-part split crank mechanism having a driving shaft, three swing rods fixed at one end to the ring and having an elongated hole at the other end and individually slidably guided to the crank shaft of the crank mechanism; a hip joint rotating shaft; And a servo mechanism for controlling the driving shaft of the crank mechanism to an output value (θa−θs) of the computing unit. 4. A robot stride control device and a steering device, characterized in that the method according to 4 is realized.   9. The steering apparatus according to claim 7, wherein a device for changing a rotational direction is interposed between the left and right bevel gear main shafts, and both of them can be driven by one actuator, and the steering according to claim 8. In the apparatus, an apparatus for changing a moving direction is interposed between two left and right moving mechanisms that change a distance between a hip joint rotation shaft and a crank mechanism driving shaft, and both can be driven by one actuator.   9. The arithmetic unit according to claim 6, 7 or 8, the step length at that time is added every time the rotation angle θa of the arm increases by π radians, and the step length at that time is reduced every time π radians decrease, and these are accumulated. A robot stride control device and a steering device characterized in that a walking distance can be measured.   7. The loading platform according to claim 6, wherein a rotary shaft attached to the front side in parallel with the hip joint axis, a seat chair fixed with the back facing the rotary shaft, and the rotary shaft controlled to an output angle from an inclination angle sensor. A stable walking device characterized in that the sitting chair is always kept horizontal regardless of the inclination of the ground.   A control panel with a built-in sensor that inputs the direction and force for tilting the heel, and the rotation direction and rotational force around the heel axis, an operation panel to which a change-over switch for selecting the posture angle pattern of the leg to be used, and an operation panel And a walking command input device comprising: a rotation direction and a rotational force of the hip joint using information from the operation panel; a circuit for determining a distinction between opening and closing of the legs and an opening and closing width; Item 12. The apparatus according to Items 5 to 11.

Images