A kind of modular six freedom-degree initiative joint type bipod walking robot
Technical field
The present invention relates to the Robotics field, all is active bipod walking robot in particular to a kind of all joints with six-freedom degree that make up with modular approach.
Background technology
Anthropomorphic robot is the superlative degree of current Robotics development and most advanced embodiment.They have the anthropoid profile of class, and also imitation is human on configuration aspects and manner of walking.Its complex structure often is made up of upper body and lower limb, has both legs and both hands, and degree of freedom often reaches 30.The realization of dynamical equilibrium when the difficult point of the core technology of anthropomorphic robot and tool challenge is double feet walking.Since the initial stage of Robotics development, double feet walking just is considered to a challenge the most highly difficult.Occur in before 30 years as far back as famous anthropomorphic robot ASIMO, QRIO and HRP-2, double feet walking is the focus and the difficult point of walking robot development always.Research the earliest and platform development can be traced back to the work that rattan one youth began in nineteen sixty-eight with Oxonian D.C.Witt in 1966 that adds of Waseda.Adding people such as rattan one youth has created in the world first and has both legs and both arms and be subjected to computer-controlled anthropomorphic robot WABOT-1 in 1973.Though be a marked achievement, WABOT-1 can only do static walking movement.Before and after 1980, great research tendency is to realize the dynamic walking of biped, a lot of researchists both at home and abroad exploitation of theoretical investigation and robot platform that begins to throw oneself into.By 1986, many biped robots that can do dynamic walking movement have been developed.Even if anthropomorphic robot has successfully been developed (releasing anthropomorphic robot P2 with Honda in 1996 is sign) today of more than ten years, biped gait planning and control remain a research focus, also have the various bipod walking robots of a lot of research institutions R and D both at home and abroad.
Domestic and international most of bipod walking robot is structurally all complicated, is made of two legs, and the joint all is active, and degree of freedom is more, and the degree of freedom of biped has 8,10, often reaches 12, the human walking of walking manner imitation, and control is complicated.Other has a class walking robot to realize dynamic walking by alternate manner, comprise allow robot at the little slope walk in the effect lower edge of potential energy and under passive walking robot, the stilt type biped robot BIPMAN2 that realizes striding by non-linear runout, realize the simple walking robot that constitutes by three connecting rods of double feet walking and the three-dimensional half passive walking machine that Massachusetts Institute of Technology (MIT) developed four actuators of an equipment by study and evolution algorithm, or the like.These biped robot's structures are simpler, and degree of freedom is less, and the joint mostly is passive or is half passive.Because all or part of joint is non-actv., robot is often realized walking by the characteristics (for example slope) of external environment.Therefore its action radius and place are very little, and walking ability is very limited.
Obviously, exploitation lower-mobility, simple in structure and walking robot that walking ability is stronger meets people's the demand and the developing direction of walking robot.
Summary of the invention
The objective of the invention is to overcome initiatively shortcomings such as walking robot complex structure, degree of freedom are many and limitation such as passive walking robot walking ability is weak, a kind of modular six freedom-degree initiative joint type bipod walking robot is provided.
For realizing purpose of the present invention, the technical solution used in the present invention is as follows:
Described robot adopts six initiatively joints, comprises two I type joints and four T type joints, and two ends are two foots.Each several part adopts series system to connect successively, and order is: foot-I type joint-T type joint-T type joint-T type joint-T type joint-I type joint-foot, promptly four T type joints are in the centre, two I type joints and foot at both ends.The rotating shaft in four T type joints is parallel to each other, and orthogonal with the rotating shaft in the I type joint at two ends.The concrete composition of robot comprises: two I type joint modules, four T type joint modules, two foot modules and a coupling bush.It is inverted U-shaped that the robotic station is immediately, and I type joint module is perpendicular to the ground.The foot module is circular or wheeled, contacts with ground by its end face.
Above-mentioned modular six freedom-degree initiative joint type bipod walking robot philtrum, described I type joint module are meant to have only a rotational freedom and joint rotating shaft and connecting rod dead in line or parallel joint module.The joint is driven by DC servo motor, and the rear end of motor directly links with the photoelectric encoder that is used to detect corner displacement and cireular frequency, and front end links to each other with harmonic speed reducer, carries out deceleration force amplifier.Harmonic speed reducer outputs to a central straight gear by an axle, and the transition wheel of central straight gear by two symmetrical distributions drives the further deceleration force amplifier of internal tooth straight-tooth crop rotation and keeps transmission direction, another part that inner gear drives joint module relatively rotates, and drives the output in joint at last.Concrete structure comprises servomotor and photoelectric encoder component 1-1, joint sleeve 1-2, motor shaft sleeve 1-3, motor cabinet 1-4, joint pedestal 1-5, roller bearing end cap 1-6, bearing seat 1-7, angular contact ball bearing and outer shaft 1-8, roller bearing end cap 1-9, inner gear 1-10, joint mouth attaching parts 1-11, transition gear axle 1-12, transition gear 1-13, harmonic speed reducer output shaft 1-14, sun gear 1-15, little roller bearing end cap 1-16, axle sleeve 1-17, angular contact ball bearing 1-18, harmonic speed reducer output transition disc 1-19, disc type harmonic speed reducer assembly 1-20.The connection mode of each parts is: servomotor and photoelectric encoder component 1-1 and motor cabinet 1-4 are fastening by axial bolt; Motor shaft links to each other with the wave producer of disc type harmonic speed reducer assembly 1-20 indirectly by motor shaft sleeve 1-3; The input and output of disc type harmonic speed reducer assembly 1-20 just wheel are fastenedly connected with motor cabinet 1-4 and harmonic speed reducer output transition disk 1-19 respectively by axial bolt, and the latter (1-19) is fastenedly connected with axial bolt and harmonic speed reducer output shaft 1-14 again; Joint sleeve 1-2 is enclosed within motor cabinet 1-4 and upward also along the circumferential direction uses radial screw fastening; Motor cabinet 1-4 is fastenedly connected by axial bolt and joint pedestal 1-5; Bearing seat 1-7 is supported on the pedestal 1-5 of joint by angular contact ball bearing and outer shaft 1-8; Angular contact ball bearing and outer shaft 1-8 are by roller bearing end cap 1-6 location and apply predetermincd tension; Harmonic speed reducer output shaft 1-14 is connected with sun gear 1-15 by two keys, and sun gear 1-15 and two transition gear 1-13 engagements that are symmetrically distributed; Two transition gear axle 1-12 are fastenedly connected by screw thread on it and joint pedestal 1-5, and are connected with transition gear 1-13 by bearing; Two transition gear 1-13 and inner gear 1-10 engagement; Inner gear 1-10, joint mouth attaching parts 1-11 and bearing seat 1-7 three are fastenedly connected by axial bolt.
Above-mentioned modular six freedom-degree initiative joint type bipod walking robot philtrum, described T type joint module has only the joint module of a rotational freedom and joint rotating shaft and connecting rod axis normal.The joint is driven by DC servo motor, and the rear end of motor directly links with the photoelectric encoder that is used to detect corner displacement and cireular frequency, and front end links to each other with harmonic speed reducer, carries out deceleration force amplifier.Harmonic speed reducer is exported by an axle, makes further deceleration and reinforcement and changes transmission direction by bevel-gear sett again.Bevel gear wheel relatively rotates by another part that a joint shaft drives joint module, carries out the output of speed and power.Concrete structure comprises servomotor and photoelectric encoder component 2-1, joint sleeve 2-2, motor cabinet 2-3, joint pedestal 2-4, angular contact ball bearing 2-5, bearing collar 2-6, internal axle sleeve 2-7, bevel pinion 2-8, gear end cap 2-9, joint shaft end cap 2-10, joint shaft 2-11, joint lid 2-12, bevel gear wheel 2-13, joint output attaching parts 2-14, joint shaft angular contact ball bearing 2-15, joint shaft end cap 2-16, roller bearing end cap 2-17, roller bearing end cap 2-18, harmonic speed reducer output shaft 2-19, harmonic speed reducer output transition disc 2-20, disc type harmonic speed reducer assembly 2-21, motor shaft sleeve 2-22.The connection mode of each parts is: servomotor and photoelectric encoder component 2-1 and motor cabinet 2-3 are fastening by axial bolt; Motor shaft links to each other with the wave producer of disc type harmonic speed reducer assembly 2-21 indirectly by motor shaft sleeve 2-22; The input and output of disc type harmonic speed reducer assembly 2-21 just wheel are fastenedly connected with motor cabinet 2-3 and harmonic speed reducer output transition disc 2-20 respectively by axial bolt, and the latter (2-20) is fastenedly connected with axial bolt and harmonic speed reducer output shaft 2-19 again; Joint sleeve 2-2 is enclosed within motor cabinet 2-3 and upward also along the circumferential direction uses radial screw fastening; Motor cabinet 2-3 is fastenedly connected by axial bolt and joint pedestal 2-4; Harmonic speed reducer output shaft 2-19 is supported in the joint bearing block 2-4 by angular contact ball bearing and bearing collar 2-5 and 2-6, and mouth is connected with bevel pinion 2-8, and 2-9 is fastening with the gear end cap; Make axially spaced-apart by internal axle sleeve 2-7 between bevel pinion 2-8 and the angular contact ball bearing 2-5; Bevel pinion 2-8 and bevel gear wheel 2-13 engagement, and the latter is installed on the joint shaft 2-11; Joint shaft 2-11 is supported on the pedestal 2-4 of joint with angular contact ball bearing 2-15, and two ends are connected by joint shaft end cap 2-10 and joint attaching parts 2-14.
Described circular foot module comprises wheel sufficient 3-1, wheel shaft 3-2, sextuple power/torque sensor 3-3 and is connected transition piece 3-4 and forms.Wheel shaft 3-2 passes the centre hole of the sufficient 3-1 of wheel, and is fastening with pad and nut at axle head; One of the end face of other end is connected with screw with the end face of power/torque sensor 3-3 and is fastening.The other end of power/torque sensor 3-3 also is connected with the transition piece 3-4 that is connected of sleeve-like with screw.The annulus of foot is rubber or foamed plastic partly, has certain elasticity, parallel to the ground with contact, play buffering and absorbing effect, protect robot to avoid large impact.Described power/torque sensor is an outsourcing piece, and 6 DOF is used for detecting along sensor coordinate system x, y, the power that z is three and around x, y, the moment that z is three.
Robot of the present invention has following characteristics:
1) robot has six initiatively joints, comprises two I type joints and four T type joints.The joint adopts series system to connect successively, and order is: I type joint-T type joint-T type joint-T type joint-T type joint-I type joint, and promptly middle is four T type joints, two ends respectively are an I type joint.The rotating shaft in four T type joints is parallel to each other, and orthogonal with the rotating shaft in I type joint, two ends.The robotic station is inverted U-shaped or the arched door shape immediately.
2) mainly form, comprise two I type joint modules, four T type joint modules and two foot modules by eight modules.Connection between the module and fastening by realizing with snap ring at its two ends.The structure of robot is simple, convenient and quick.
3) biped of robot is circular or wheeled module, contacts with ground by having certain elastomeric circumferential section, plays buffering absorbing effect.
The present invention compared with prior art has following advantage and effect:
(1) degree of freedom of robot is few, has only six, realizes initiatively walking with degree of freedom seldom, and the robot architecture is relative simple with control;
(2) the present invention adopts modular approach to make up robot system, and main body only is made up of two kinds of joint modules, makes up easily, design, makes and safeguards that simply cost is lower;
(3) the present invention is directed to the robot construction characteristics, can adopt three kinds of special walking patterns, comprise and reverse gait, traversing gait and upset gait, have control simple, realize easily, good to the comformability of environment, obstacle climbing ability is strong, the little characteristics of energy consumption;
(4) robot body that the present invention created is actually the mechanical arm of a six degree of freedom, and the fixing back of the end other end can be realized various poses in its working space, thereby this robot has certain operating function;
(5), lie in and adjust on the ground a next shape and promptly can be used as the mobile robot and use as long as the robot that the present invention created installs a cardan wheel additional.
Description of drawings
Fig. 1 is a robot External view of the present invention;
Fig. 2 is a robot mechanism scheme drawing of the present invention;
Fig. 3 is an I type joint module External view of the present invention;
Fig. 4 is an I type joint module section-drawing of the present invention;
Fig. 5 is a T type joint module External view of the present invention;
Fig. 6 is a T type joint module section-drawing of the present invention;
Fig. 7 is circular foot module of the present invention and connects External view;
Fig. 8 is circular foot module of the present invention and bonded assembly section-drawing thereof;
Fig. 9 is first kind of walking pattern of robot of the present invention-reverse schematic top plan view of gait;
Figure 10 is the scheme drawing of second kind of walking pattern-traversing gait of robot of the present invention;
Figure 11 is the scheme drawing of the third walking pattern-upset gait of robot of the present invention.
The specific embodiment
In order to understand the present invention better, below in conjunction with accompanying drawing the present invention is done to describe further, but embodiments of the present invention are not limited thereto.
Fig. 1 and Fig. 2 show the External view and the structural scheme of mechanism of the robot of the present invention's structure respectively.As shown in the figure, robot has six-freedom degree, has eight modules.Body is made up of six joint module 0-2 and 0-3, and two ends respectively meet a sufficient module 0-1.Each module connects with series system successively, and order is: foot-force gauge-I type joint-T type joint-T type joint-T type joint-T type joint-I type joint-force gauge-foot.The centre is four T type joint module 0-3, and middle the adjustment with a transition sleeve 0-4 connects distance.Connect with snap ring 0-4 between each joint module.The interior ring vertical section of snap ring is recessed dovetail groove, and snap ring has individual opening, and opening portion passes bolt, tightens two parts that screw bolt and nut on the snap ring can will link to each other and is fastenedly connected.The joint rotating shaft of four T type joint module 0-3 is parallel to each other, and vertical with the joint shaft of the I type joint module at two ends.They constitute a four-bar linkage.Can change the shape of this four-bar linkage and then the center of gravity of adjustment robot by the angular transposition that changes these four T shape joints simultaneously.When robot was upright, the side of two wheel foots contacted with ground, and two I type joints are perpendicular to the ground, and the configuration of robot is the U word of handstand, and two legs is identical and symmetrical.
Be respectively the External view and the section-drawing of I type joint module as shown in Figure 3 and Figure 4.The rotating shaft of I type joint module and the dead in line of joint connecting rod or parallel.Parts comprise: servomotor and photoelectric encoder component 1-1, joint sleeve 1-2, motor shaft sleeve 1-3, motor cabinet 1-4, joint pedestal 1-5, roller bearing end cap 1-6, bearing seat 1-7, angular contact ball bearing and outer shaft 1-8, roller bearing end cap 1-9, inner gear 1-10, joint mouth attaching parts 1-11, transition gear axle 1-12, transition gear 1-13, harmonic speed reducer output shaft 1-14, sun gear 1-15, little roller bearing end cap 1-16, axle sleeve 1-17, angular contact ball bearing 1-18, harmonic speed reducer output transition disc 1-19 and disc type harmonic speed reducer assembly 1-20.Drive motor is a DC servo motor, and motor is integrated with the photoelectric encoder that is used for angular transposition and angular velocity detection, and promptly direct connection photoelectric encoder in motor shaft rear end becomes servomotor and photoelectric encoder component 1-1.The front end face of motor is connected with screw (vertically) with motor cabinet 1-4.The end of the joint sleeve 1-2 of motor outside is enclosed within on the motor cabinet 1-4, and along the circumferential direction is connected with screw (radially) with motor cabinet 1-4.Motor cabinet 1-4 and joint pedestal 1-5 are also fastening vertically with screw.The output shaft of motor is connected with motor shaft sleeve 1-3, and is fastening with two radial direction top threads.Motor shaft sleeve 1-3 is connected with the wave producer of harmonic speed reducer 1-20, by a straight key transmitting movement and power.In order to obtain less joint module length, one-level is slowed down and is adopted the harmonic speed reducer three-major-items 1-2 of flat disk, input wherein just wheel is fastening vertically with screw with motor cabinet 1-4, output just wheel is fastenedly connected with harmonic speed reducer transition disk 1-19 vertically with screw, and transition disk 1-19 uses by screw again and is connected with harmonic speed reducer output shaft 1-14.Ripple reducer output shaft 1-14 is supported among the pedestal 1-5 of joint by a pair of angular contact bearing 1-18, and inner ring sleeve 1-17 is arranged between two bearings, and an end is located and pretension with bearing carrier ring 1-16.A straight gear is installed as sun gear 1-15 on the mouth of ripple reducer output shaft 1-14, by two the straight key transmitting movements and the power of symmetry.The transition straight gear 1-13 engagement of sun gear 1-15 and two symmetrical distributions.Each transition straight gear 1-13 is bearing on its gear wheel shaft 1-12 by the bearing in the endoporus, and the latter (1-12) is fixedly mounted on the pedestal 1-5 of joint by the screw thread on it.Transition straight gear 1-13 and inner gear 1-10 engagement.It is fastening that inner gear 1-10, bearing seat 1-7 and joint mouth attaching parts 1-11 three are connected by axial bolt, becomes the last output block of joint module.This output output block is bearing on the pedestal 1-5 of joint by a pair of angular contact ball bearing and outer shaft 1-8.Roller bearing end cap 1-6 carries out axial location and pretension to this diagonal angle contact ball bearing.The working process and the motion principle of this joint module are as follows: the output shaft of motor orders about motor shaft sleeve 1-3 and rotates, and motor shaft sleeve 1-3 drives the wave producer of harmonic speed reducer 1-20.Harmonic speed reducer 1-20 deceleration force amplifier, by output shaft 1-14 will move and transmission of power to sun gear 1-15.Sun gear 1-15 drives two transition gear 1-13, and then drives inner gear 1-10.Inner gear 1-10 and bearing seat 1-7 and joint mouth attaching parts 1-11 are fastening, finish the motion of whole joint module and the output of power.
Be respectively the External view and the section-drawing of T type joint module as shown in Figure 5 and Figure 6.The rotating shaft of T type joint module and the axis of joint connecting rod are orthogonal.Parts comprise: servomotor and photoelectric encoder component 2-1, joint sleeve 2-2, motor cabinet 2-3, joint pedestal 2-4, angular contact ball bearing 2-5, bearing collar 2-6, internal axle sleeve 2-7, bevel pinion 2-8, gear end cap 2-9, joint shaft end cap 2-10, joint shaft 2-11, joint lid 2-12, bevel gear wheel 2-13, joint attaching parts 2-14, joint shaft angular contact ball bearing 2-15, joint shaft end cap 2-16, roller bearing end cap 2-17, roller bearing end cap 2-18, harmonic speed reducer output shaft 2-19, harmonic speed reducer output transition disc 2-20, disc type harmonic speed reducer assembly 2-21 and motor shaft sleeve 2-22.Drive motor is a DC servo motor, and motor is integrated with the photoelectric encoder that is used for angular transposition and angular velocity detection, and promptly direct connection photoelectric encoder in motor shaft rear end becomes servomotor and photoelectric encoder component 2-1.The front end face of motor is connected with screw (vertically) with motor cabinet 2-3.The end of the joint sleeve 2-2 of motor outside is enclosed within on the motor cabinet 2-3, and along the circumferential direction is connected with screw (radially) with motor cabinet 2-3.Motor cabinet 2-3 and joint pedestal 2-4 are also fastening vertically with screw.The output shaft of motor is connected with motor shaft sleeve 2-22, and is fastening with two radial direction top threads.Motor shaft sleeve 2-22 is connected with the wave producer of harmonic speed reducer 2-21, by a straight key transmitting movement and power.In order to obtain less joint module length, one-level is slowed down and is adopted the harmonic speed reducer three big 2-21 of flat disk, input wherein just wheel is fastening vertically with screw with motor cabinet 2-3, output just wheel is fastenedly connected with harmonic speed reducer transition disk 2-20 vertically with screw, and transition disk 2-20 uses by screw again and is connected with harmonic speed reducer output shaft 2-19.Ripple reducer output shaft 2-19 is supported among the pedestal 2-4 of joint by a pair of angular contact bearing 2-5, between two bearings bearing carrier ring 2-6 is arranged, and an end carries out axial location and pretension with bearing carrier ring 2-18.A bevel pinion 2-8 is installed on the mouth of ripple reducer output shaft 2-19, and by two the straight key transmitting movements and the power of symmetry, 2-9 makes axial locking with the gear end cap.Make axially spaced-apart with internal axle sleeve 2-7 between bevel pinion 2-8 and the angular contact bearing 2-5.Bevel pinion 2-8 and bevel gear wheel 2-13 engagement, and the latter is installed on the joint shaft 2-11, by pair of straight key transmitting movement and power.Joint shaft 2-11 is supported on the pedestal 2-4 of joint with a pair of angular contact ball bearing 2-15, and two roller bearing end cap 2-17 diagonal angle contact ball bearing 2-15 carry out axial location and pretension.Joint shaft 2-11 two ends are connected by two end cap 2-10 and joint attaching parts 2-14, and carry out axial location and locking with end cap 2-16.The working process and the motion principle of this joint module are as follows: the output shaft of motor orders about motor shaft sleeve 2-22 and rotates, and motor shaft sleeve 2-22 drives the wave producer of harmonic speed reducer 2-21.Harmonic speed reducer 2-21 deceleration force amplifier, by output shaft 2-19 will move and transmission of power to bevel pinion 2-8.Bevel pinion 2-8 drives bevel gear wheel 2-13, has realized that 90 degree of sense of motion change.Bevel gear wheel 2-13 will move and transmission of power to joint shaft 2-11, and the latter and joint shaft end cap 2-10 are affixed, will move with transmission of power to joint attaching parts 2-14.The motion of whole joint module and power are by joint attaching parts 2-14 output.
Be the External view and the section-drawing of foot module and connecting bridge thereof as shown in Figure 7 and Figure 8., take turns sufficient module and comprise wheel sufficient 3-1, wheel shaft 3-2, sextuple power/torque sensor 3-3 and be connected transition piece 3-4 composition as circular foot with trundle.Wheel shaft 3-2 passes the centre hole of the sufficient 3-1 wheel hub of wheel, and is fastening with pad and nut at axle head; The end face of other end is connected with screw with the end face of a power/torque sensor 3-3 and is fastening.The other end of power/torque sensor 3-3 also is connected with the transition piece 3-4 that is connected of sleeve-like with screw.The annulus of foot is rubber or foamed plastic partly, has certain elasticity, parallel to the ground with contact, play buffering and absorbing effect, protect robot to avoid large impact.Described power/torque sensor is an outsourcing piece, and 6 DOF is used for detecting along sensor coordinate system x, y, the power that z is three and around x, y, the moment that z is three.
It is multiple walking pattern that biped robot of the present invention has multiple gait, shown in Fig. 9,10 and 11.Be illustrated in figure 9 as and reverse gait (birds-eye view, circular represent foot position), the numeral among the figure is a sequence of operation number.Its concrete steps are: 1) Shang Duan four T type joint T1~T4 drive the four-bar linkage motion that is made of them, the barycenter of robot or ZMP (zero-g is apart from point) are adjusted in the bearing surface that feet forms (for example sequence number is 2 left foot among the figure); 2) motion is continued in four T type joints of upper end, and another pin (pin that moves about, for example sequence number is 1 right crus of diaphragm among the figure) is lifted away from ground; 3) ankle-joint of feet (for example I type joint I1) rotates robot is rotated around the ankle-joint axle of vertical ground, the position of the pin that moves about is changed (for example sequence number is that 1 right crus of diaphragm position is 3 right crus of diaphragm position to sequence number from figure); 4) Shang Duan four T types joint motions, the pin that will move about is put into ground; 5) feet and the role exchange of pin of moving about, the step above repeating, the front and back of two foots change in proper order, and robot can be realized advancing, retreat, turn to, turning round and various walkings actions such as stair activity.
Be traversing gait (lateral plan) as shown in figure 10, numeral is a sequence of operation number among the figure.Its concrete steps are: 1) Shang Duan four T type joint T1~T4 drive the four-bar linkage motion that is made of them, and the barycenter of robot or ZMP (zero-g is apart from point) are adjusted in the bearing surface that feet forms; 2) motion is continued in four T type joints of upper end, another pin (pin moves about) is lifted away from ground, and makes it mobile forward or backward, and feet (for example I type joint I1) reverses to change direction of travel in case of necessity; 3) motion is continued in four T type joints of upper end, and the pin that will move about is put into ground; 4) role exchange of the feet and the pin that moves about, the front and back order of two foots is constant, the step above repeating, robot is promptly realized various walking actions.
Be upset gait (lateral plan) as shown in figure 11, numeral is a sequence of operation number among the figure, its concrete steps are: 1) Shang Duan four T type joint T1~T4 drive the motion of its four-bar mechanism, and the barycenter of robot or ZMP (zero-g is apart from point) are adjusted in the bearing surface that feet forms; 2) Shang Duan four T type joints are rotated further, and another pin (pin moves about) is lifted away from ground, rising, and around the upset of the T type joint of feet upper end, feet (for example I type joint I1) reverses to change direction of travel in case of necessity; 3) four T type joints of upper end are done to continue motion, and ground falls, is put in the underfooting of will moving about; 4) role exchange of the feet and the pin that moves about, the step above repeating, the front and back of two foots change in proper order, and robot is realized various walking actions.