RU2272705C2 - Support reaction evaluating method amd method for evaluating moments of articulated joints of double-leg walking body - Google Patents

Abstract

FIELD: measuring technique, possibly measurements of support reaction efforts acting upon legs of walking moving bodies, evaluation of efforts acting upon articulated joints of legs of such bodies.

SUBSTANCE: method comprises steps of evaluating reaction of support according to number of body legs touching support. Calculated values of support reaction efforts are received with use of techniques depending upon respective supporting states. For example, when double-leg walking moving body rests upon one support, designed value of support reaction effort is received from mass value, gravity acceleration and gravity center acceleration of walking body. When double-leg walking body rests upon two supports, designed values of support reaction efforts are received on base of mass value, gravity acceleration and acceleration of gravity center of walking moving body and from positions of concrete part of each leg relative to gravity center. Method for evaluating moments of articulated joints of double-leg walking body is realized due to using reverse-dynamic model while taking into account support reaction efforts.

EFFECT: possibility for determining support reaction efforts acting upon legs of walking body and moments acting upon articulated joints of its leg in real time.

9 cl, 15 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a method for evaluating the reaction forces of a support (floor) acting on the legs of a bipedal walking moving body, such as a person or a bipedal walking robot, and further relates to a method for evaluating the moments acting on the joints of the legs of a bipedal walking moving body, using calculated forces support reactions.

BACKGROUND OF THE INVENTION

For example, when performing operational control of a device to facilitate walking, facilitating human walking movements, or controlling the movements of a moving two-legged walking robot, it becomes necessary to sequentially determine the reaction forces of the support acting on the legs (in particular, the forces acting on the parts of the legs touching the ground from support (gender)) of a person or a two-legged walking robot. By determining the reaction forces of the support, it becomes possible to determine the moments or similar influences acting on the joints of the legs of a bipedal walking moving body, and based on the obtained moments or similar influences, it becomes possible to determine the required forces of the device needed to facilitate walking, or the required torques for the corresponding joints of the biped walking robot or similar device.

The methodology for determining the aforementioned reaction forces of the support is known and described, for example, in publication No. 2000-249570 of the unexamined patent application. In accordance with this methodology, the shape, bearing in mind that the waveform of a temporary change in the reaction force of the support on each leg, periodically changes during the constant walking of the bipedal walking moving body, the reaction force of the support on each leg is perceived as a complex quantity (linear combination) of many trigonometric functions having mutually different periods of 1 / n (n = 1, 2, ...) of the walking period. In this case, as the weight coefficient of each trigonometric function, when combining many trigonometric functions, a predetermined value determined in advance for a two-legged walking moving body, or a value obtained due to its adjustment depending on the geographical and geometric features of the area, was used.

However, despite the fact that the above methodology helps in determining the reaction forces of the support acting on the legs with respect to one step or the set of steps of a two-legged walking moving body, if the walking of the two-legged walking moving body changes sequentially, it is difficult to accurately determine the reaction forces of the support. In addition, to increase the accuracy of determining the reaction forces of the support, it is necessary to establish the above weighting coefficients of trigonometric functions on a bipedal walking moving body, or to adjust them depending on the geographic and geometric features of the terrain or similar factors. Thus, it is difficult to determine the reaction forces of the support with a decrease in the influence of the environment on the movement of the bipedal walking moving body or with a difference in the individuality of the bipedal walking moving body.

For example, in the case of a bipedal walking robot, one is known in which force sensors, for example six-axis force sensors, are attached to the ankles or feet of the corresponding legs, and the reaction forces of the support are obtained due to the output signals of these force sensors. In addition, the methodology of walking a biped walking walking body on a punch plate placed on a support (floor) is also known, and the reaction forces of the support are determined using the output signals of the punch plate.

However, the methodology in which force sensors are used has the disadvantage that when determining the reaction forces of the support on the legs, in particular, of a person, since force sensors must be attached to the ankles or feet of a person, force sensors become obstructive for walking in normal environment of existence. In addition, when using the punch plate, the reaction forces of the support can only be determined in the environment where the punch plate is located.

The present invention was developed in view of the drawbacks of the prior art, and its object was to provide a method for evaluating support reaction forces in real time using a relatively simple technique, and which is suitable for determining support reaction forces with respect to in particular, to a person as a two-legged walking moving body.

In addition, it is an object of the present invention to provide a method for evaluating the moments of joints of a bipedal walking moving body, which enables accurate real-time determination of the moments acting on joints, such as knee joints of the legs, by using the calculated support reaction forces.

SUMMARY OF THE INVENTION

In the beginning, an explanation will be given of the basic principles of the method corresponding to the present invention, of evaluating the reaction force of the support of a bipedal walking moving body.

As the state of movement of the legs of a bipedal walking moving body, for example, as the state of movement of the legs when walking, there is a state of one position (touch), in which, as illustrated in figure 1 (a), only one leg 2 (the leg on the front side in the direction of movement illustrated in the drawing) of both legs 2.2 of the bipedal walking moving body 1 touches the ground, and the state of two positions (touch) in which both legs 2.2 touch the ground, as shown in figure 1 (b).

In this case, first of all, in the above state of one position, the equation of motion for the center of gravity (in particular, the equation of translational displacement of the center of gravity) of a two-legged walking moving body in an absolute coordinate system fixed relative to the ground on which the two-legged walking moving body is given the expression of the dependence in which the product of the acceleration of the center of gravity and the mass of the bipedal walking moving body is equal to the resulting force of gravity acting on the center of gravity (= mass of the two walking body moving (acceleration of gravity), and the reaction force of the support acting from the support on the touching part of the foot touching the ground. In particular, as, for example, shown in Fig. 1 (a), in the absolute coordinate system Cf fixed relative to the support A, it is given that the acceleration components a of the center of gravity G0 of the bipedal walking moving body 1 in the direction of the X axis (horizontal direction in the direction the forward movement of the two walking moving body 1) and the Z-axis direction (vertical direction) are components ax and az, respectively, and the components F of the reaction force of the support acting on foot 2 (foot 2 on the supporting side of the foot) touching the ground in the direction of and X and in the direction of the Z axis are the components Fx and Fz, respectively, and the equation of motion for the center of gravity G0 is the following equation (1):

(in which M is the mass of the bipedal walking moving body, and g is the acceleration of gravity).

The brackets of the part ^T (,) on both sides in equation (1) represent two-component vectors. In the above description, the notation in the form of ^T (,) represents a vector.

Thus, if the acceleration a = ^T (ax, az) of the center of gravity G0 of a bipedal walking moving body 1 is determined, then the calculated value of the force F = (Fx, Fz) of the support reaction can be obtained using the following equation (2) using acceleration a , the mass M of the bipedal walking moving body 1 and the acceleration value g of gravity.

In this case, the mass M necessary to obtain the calculated value of the support reaction force F can be determined in advance by measurement or the like. In addition, with regard to the position of the center of gravity and acceleration G0, a, they can be determined sequentially in accordance with a known method in which the output signals of sensors, for example sensors, are used to determine the bending catch (rotation angles) of the corresponding joints of a biped walking moving body 1, meter accelerations, gyro sensors and so on, as will be described in detail later.

Then, the equation of motion for the center of gravity (in particular, the equation of displacement of the center of gravity) of a bipedal walking moving body in the above state of touching the ground with both legs is given by an expression of dependence in which the product of the acceleration of the center of gravity and the mass of the bipedal walking moving body is equal to the resulting gravity acting on center of gravity (= mass of a bipedal walking moving body × acceleration of gravity), and support reaction forces acting from the support on the corresponding parts of the ground touching their feet (two floor reaction force corresponding to both feet, respectively). In particular, as shown in FIG. 1 (b), if the coordinate components X and Z of the reaction force Ft support the leg 2 on the front side in the forward direction of the bipedal walking moving body 1 are Ffx and Ffz, and the coordinate components X and Z forces of the reaction Fr support on the leg 2 on the rear side are Frx and Frz, respectively, then equation (2) of the center of gravity G0 is expressed by the following equation (3):

The values of ax, az, M, and g in equation (3) are described above.

On the other hand, in accordance with the knowledge of the authors of this application, in the state of two positions of the force Ff, Fr, the support reactions acting on the legs 2, 2, respectively, can seem to act from specific parts 12f, 12r (e.g., ankles) in the vicinity the lower end parts of the corresponding legs 2.2 to the center of gravity G0 of the bipedal walking moving body 1, as shown in figure 1 (b). After this, an expression of a certain relationship is established between the position of the specific part 12f, 12r of the leg 2 relative to the center of gravity G0 and the force Ff, Fr of the support reaction acting on the leg 2, that is, the dependence expression representing the dependence in which the direction of the segment connecting between the center of gravity G0 and the specific part 12f, 12r of leg 2 (the direction of the radius vector of the specific part 12f, 12r relative to the center of gravity G0) is similar to the direction of the reaction force Ff, Fr of the support relating to leg 2.

In particular, as follows from Fig. 1 (b), it is given that the coordinates of the position of the center of gravity G0 in the above-mentioned absolute coordinate system Cf are the coordinates Xg, Zg, the coordinates of the position of the specific part 12f of the front side foot 2 are the coordinates Xf, Zf, and the coordinates the position of the specific part 12r of the legs 2 of the rear side are the coordinates Xr, Zr, while the above expression of dependence take the form of equations (4).

After that, from these equations (4) and the aforementioned equation (3), the following equations (5) are obtained.

(in which ΔZf = Xf-Xg, ΔZf = Zf-Zg, ΔXr = Xr-Xg, ΔZr = Zr-Zg)

Thus, if the acceleration a = ^T (ax, az) of the center of gravity G0 of the bipedal walking moving body 1 is determined and the positions (they are expressed by ΔXf, ΔZf, ΔXr and ΔZr in equations (5)) of the specific parts 12f, 12r, respectively, of the legs are determined 2.2 relative to the center of gravity G0 of the bipedal walking moving body 1, then the calculated values of the forces Ff = ^T (Ffx, Ffz), Fr = ^T (Frx, Frz) of the support reaction acting on the corresponding legs 2.2 can be obtained using the above equations (5) when using the mass value M and the acceleration value of gravity g of a bipedal walking movement egosya body 1 and a certain acceleration and position of specific parts 12f, 12r.

In this case, the mass M necessary to obtain the calculated values of the reaction forces Ff, Fr of the support can be determined in advance by measurement or the like. Regarding the acceleration of the center of gravity G0, the position of the center of gravity G0 and the position of specific parts 12f, 12r relative to the center of gravity G0, although the details will be described later, can be determined sequentially using a known methodology or in a similar way using the output signals of sensors that detect bending angles ( rotation angles) of the corresponding joints of the biped walking walking body 1, acceleration meters, gyro sensors, and so on.

The present invention will now be described based on what has been explained above. To solve the aforementioned problems, a method for evaluating a support reaction force for a bipedal walking moving body in accordance with the present invention, that is, a method for estimating a reaction force of a support acting on each leg of a bipedal walking moving body, comprises a first step of assessing whether the state of movement of the legs of said bipedal a walking moving body with a state of one position in which only one of the legs touches the ground, or a state of two positions in which both legs touch the ground; the second stage, during which successively determine the position of the center of gravity of the specified biped walking moving body and sequentially determine the acceleration of the specified center of gravity in the absolute coordinate system relative to the ground by using data from a time series of positions of the specified center of gravity; and a third step, during which the position of the specific part relative to the specified center of gravity is determined, at least in the indicated state of the two positions, said specific part being predefined in the vicinity of the lower end part of each leg. In this case, the method for evaluating the reaction force of the support in accordance with the present invention is characterized in that it further comprises the step of obtaining calculated values of said reaction force of the support acting on the foot touching the ground, sequentially, in a state of one position of said bipedal walking moving body based on the equation of motion for the specified center of gravity, expressed using mass and acceleration of gravity of the bipedal walking moving body, acceleration of the specified center of gravity and indicated with silt reaction support, acting on the foot, touching the ground; and the step of obtaining the calculated values of the indicated reaction forces of the support, respectively acting on both legs, sequentially, in the state of two positions of the indicated biped walking moving body based on the equation of motion for the specified center of gravity, expressed using mass and acceleration of gravity of the biped walking walking body, acceleration the specified center of gravity and the indicated reaction forces of the support, respectively acting on both legs, and the expression of the relationship between the position of the specified specific part of each leg from ositelno said center of gravity and said force acting on said foot floor reaction wherein said relationship is determined based on the assumption that, acting on each said foot floor reaction force acts from said specific portion of said leg to said center of gravity.

In accordance with the present invention, as described above, in the aforementioned first step, it is evaluated whether the state of movement of the legs of the bipedal walking moving body is a state of one position or a state of two positions, and the calculated values of the aforementioned reaction forces of the support are obtained using techniques that depend on the respective reference states . In particular, in the state of one position of the bipedal walking moving body, the calculated value of the aforementioned reaction force of the support acting on the foot touching the ground is obtained from the values of mass, acceleration of gravity and acceleration of the center of gravity of the bipedal walking moving body (see equation (2)) based on the above equation of motion of the center of gravity of a bipedal walking moving body (see equation (1)).

On the other hand, in a state of two positions of a bipedal walking moving body, the calculated values of the reaction forces of the support acting on both legs, respectively, are obtained from mass, acceleration of gravity and acceleration of the center of gravity of the bipedal walking moving body, and the position of the specific part of each leg relative to the center of gravity (see equation (5)) based on the above equation of motion for the center of gravity of a bipedal walking moving body (see equation (3)) and the relationship expression (equation (4)) between the position of the conc the back of each leg with respect to the aforementioned center of gravity and the aforementioned reaction force of the support acting on the leg of the subject. Incidentally, in the state of one position, the reaction force of the support acting on the free leg (the leg not touching the ground) is zero.

In this case, the mass of the bipedal walking moving body necessary to obtain the calculated value of the reaction force of the support can be obtained in advance by measurement or a similar method. As for the position of the center of gravity and acceleration of the bipedal walking moving body and the position of the specific part of each leg relative to the center of gravity, it seems possible to determine them in real time using these output signals of the sensors, which are relatively small in size and easy to attach to the bipedal walking moving the body, for example sensors (potentiometers or similar devices) detecting the bending angles (rotation angles) of the corresponding joints of the biped walking walking bodies, accelerometers, gyro sensors, and so on.

Thus, in accordance with the support reaction force estimation method according to the present invention, it is possible to determine the support reaction forces in real time using a relatively simple technique without attaching force sensors to the ankles or feet of a bipedal walking moving body or using a punch plate.

In the method for evaluating the support reaction force of the present invention as described above, it is preferred that the ankle of the foot is a specific part of each leg. In accordance with this, the reliability of the above assumption is particularly increased in the state of touching the ground with both legs. Thus, the accuracy of not only the calculated value of the support reaction force in the aforementioned state of one position, but also the calculated values of the reaction force of the support in the state of two positions can be increased. That is, the reaction force of the support can be accurately estimated regardless of the state of movement of the legs.

In addition, a method for evaluating the support reaction force according to the present invention includes the step of measuring the up and down acceleration of the lower body supported on both legs through the hip joint of each leg, said lower body being located close to said hip joints, in which in said first step, the state of motion of said biped walking body is evaluated so that if the acceleration of said lower body in an up-down direction increases If it starts to a predetermined threshold value or more, then the indicated state of two positions starts, while the state of one position ends, and if the calculated value of the indicated reaction force of the support acting on the leg, which is going to make a separation (from the ground surface), decreases to a predetermined threshold values or less in the indicated state of two positions, then the indicated state of two positions ends, while the indicated state of one position begins.

In particular, when the state of movement of the legs changes from one state to two states during the movement (while walking) of a two-legged walking moving body, the landing of the free leg causes the lower body to accelerate up and down (acceleration up) to temporarily become extremely great. This phenomenon does not normally occur in another state of leg movement. On the other hand, when the state of movement of the legs changes from the state of two positions to the state of one position, the tearing operation (from the ground surface) of one of the legs causes the reaction force of the support acting on this leg to decrease to zero. Thus, by assessing the state of movement of the legs, as described above, a correct judgment can be obtained on whether they are in the state of one position or in the state of two positions. As a result, the method of calculating the calculated value of the reaction force of the support, which distinguishes the state of one position from the state of two positions, can be activated with adequate synchronization in order to increase the accuracy of the calculated value of the reaction force of the support. The acceleration in the up and down direction of the lower body, necessary for assessing the state of movement of the legs, can simply be determined from the output signals of the acceleration meter, for example, by attaching the acceleration meter to the lower body.

If the aforementioned body, for example, like a human body, has a waist connected to both legs through the hip joints and a chest located on the waist so as to freely deviate from the waist, it is preferable that the acceleration to be measured in the up-down direction of the lower body part was the acceleration of the waist in the up and down direction.

In addition, in the method for evaluating the support reaction force of the present invention, various techniques are considered as methods for determining the position of the center of gravity of a bipedal walking moving body and acceleration of the center of gravity in the aforementioned second step, and it is possible to use various known methods. However, it is preferable to determine the position of the center of gravity and the acceleration of the center of gravity in accordance with the following method.

In particular, the method comprises the step of appropriately measuring the angle of deviation of the body supported on both legs through the hip joint of each leg, the bending angles of at least the hip joint and the knee joint of each leg, and accelerating the predetermined reference point of said biped walking body in the specified absolute coordinate system in which at the specified second stage, based on the deflection angle of the specified body, the bending angles, respectively, of the specified hip joints and said knee joints, a rigid body coupling model formed by expressing said biped walking walking body as a connected body from a plurality of rigid bodies, predetermined masses of corresponding parts of corresponding rigid two-legged walking moving body bodies corresponding to corresponding rigid bodies of said rigid body coupling model, and the provisions of the predefined centers of gravity of the corresponding parts of the rigid body in the corresponding parts of the corresponding are rigid bodies, sequentially determine the position of the center of gravity of the indicated bipedal walking moving body relative to the specified reference point, the acceleration of the specified center of gravity relative to the specified reference point is sequentially determined based on the data of the time series of the positions of the specified center of gravity, and the acceleration of the specified center of gravity in the specified absolute coordinate system is obtained from the acceleration the specified center of gravity relative to the specified reference point and the acceleration of the specified reference point in the specified absolute the exact coordinate system.

In particular, if the reference point is set arbitrarily for the bipedal walking moving body, then the position of the center of gravity of the bipedal walking moving body relative to the reference point is almost determined by the mutual postural dependence in the thigh body of each leg from the hip joint to the knee joint and lower leg on the lower side below the knee joint. By measuring the angle of deviation of the body and the angles of bending, respectively, of the hip joints and knee joints, this postural relationship can be determined from these measurement data. In addition, although the details will be described later, if it is assumed that the aforementioned rigid body coupling model is intended to model a bipedal walking moving body (for example, a model considered as rigid part bodies (including the body) on the upper side of the hip joints of both legs of a bipedal walking moving body body and thighs and lower legs of each leg), then the position of the center of gravity of the bipedal walking moving body relative to the aforementioned reference point can be determined based on the masses corresponding parts corresponding to the rigid bodies of the bipedal walking moving body, the center of gravity of the relevant parts of the rigid body (in particular, the provisions of the relevant parts of the respective rigid bodies in a coordinate system fixed in the relevant parts of the respective rigid bodies) and the aforementioned postural dependence. In addition, the acceleration of the center of gravity relative to the reference point can be obtained as a differentiated second-order value of the position of the center of gravity, which is determined from the data of the time series of the positions of the center of gravity. Thus, by measuring the acceleration of the reference point in the aforementioned absolute coordinate system, the acceleration of the center of gravity of the bipedal walking moving body can be obtained as the total (complex) acceleration of the acceleration of the center of gravity relative to the reference point and the acceleration of the reference point.

In this case, the body deflection angles necessary to obtain acceleration of the bipedal walking moving body, as described above, can be obtained from the output signals of acceleration meters and gyro sensors or deflection meters or similar devices attached to the body, and the flexion angles of the hip joint and knee joint of each legs can be obtained from the output signals of sensors, for example, potentiometers attached to parts of the respective joints. In addition, the acceleration of the reference point in the absolute coordinate system can be obtained from the output signals of the sensors, for example, acceleration meters, attached to the part forming a whole with the reference point. In addition, the masses of the corresponding parts of the corresponding rigid bodies of the biped walking walking body and the positions of the centers of gravity of the corresponding parts of the rigid body in the corresponding parts of the rigid bodies can be obtained in advance by measurement or the like.

Thus, it becomes possible to simply determine in real time the position and acceleration of the center of gravity of a bipedal walking moving body without mounting relatively large sensors and so on to the bipedal walking moving body.

When determining the position and acceleration of the center of gravity of a bipedal walking moving body, it is preferable that the reference point be mounted on the body. Accordingly, sensors, for example acceleration meters, designed to measure the acceleration of a reference point in an absolute coordinate system, can be mounted on the body and, thus, the sensors attached to the legs can be reduced to accordingly prevent a situation in which the sensors begin to interfere with the walking movements of the bipedal walking moving body.

On the other hand, if a body similar to a human body has a waist connected to both legs through the hip joints and a chest located on the waist so as to deviate from the waist, it is preferable that the body deflection angle used to determine the center position severity, contained the angles of deviation of the waist and chest, respectively. In particular, in this case, it is preferable that the aforementioned rigid body communication model is a model expressing the shin located on the lower side of the knee joint of each leg of the bipedal walking moving body, the hip between the knee joint and the hip joint, waist and upper body, located on the upper side of the waist and including the chest, as rigid bodies, respectively.

In accordance with this, especially if the two-legged walking body is a man, then the position of its center of gravity and its acceleration can be precisely determined in order to increase the accuracy of the calculated values of the reaction forces of the support.

When determining the position of the center of gravity of the bipedal walking moving body relative to the reference point based on the body deflection angles and so on, as described above, the position of the specific part of each leg relative to the center of gravity of the bipedal walking moving body can be determined by determining the position of the specific part relative to the reference point on the above third stage. In this case, the parameters necessary to determine the position of a particular part relative to the reference point differ depending on the established position of the reference point. For example, if the specific part is the ankle of each leg, and the reference point is mounted on the body, then you can determine the position of the specific part of each leg relative to the reference point based on the angle of deviation of the body (the angle of deviation of the waist, if the body has a waist and chest, and the reference point is set at the waist), the flexion angles of the hip joint and knee joint of each leg, and the size (length) of the thigh and lower leg of each leg.

In such a case, the moment estimation method for the bipedal walking moving body according to the present invention is a method for estimating the moment acting on at least one joint of each leg of the bipedal walking moving body by using the calculated values of the support reaction force on each leg in series obtained using the aforementioned method for evaluating the reaction force of the support. In such a case, the moment estimation method according to the present invention is characterized in that it comprises the step of appropriately measuring the angle of deviation of the body supported on both legs, through the hip joint of each leg, the flexion angles, respectively, of at least the hip joint and knee joint of each legs, and acceleration of a given reference point of the specified biped walking walking body in the specified absolute coordinate system; the step of sequentially determining the deflection angles of the corresponding parts of the corresponding rigid bodies of the bipedal walking moving body corresponding to the rigid bodies of the indicated rigid body communication model, based on the deflection angle of the specified body, the bending angles of the specified hip joint and the specified knee joint of each leg, and the communication model rigid bodies formed by expressing said biped walking walking body as a connected body from a plurality of rigid bodies; the step of sequentially determining the positions of the centers of gravity of the corresponding parts of the respective rigid bodies relative to the indicated reference point based on the deflection angles of the indicated corresponding parts of the respective rigid bodies, the predetermined masses of the corresponding parts of the corresponding rigid bodies and the positions of the predefined centers of gravity of the corresponding parts of the rigid bodies in the corresponding parts of the corresponding rigid bodies , and sequentially determining the accelerations of the centers of gravity of the co sponding portions corresponding to the rigid bodies with respect to said reference point based on time series data center of gravity position corresponding portions corresponding to the rigid bodies; the step of sequentially determining the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid bodies in the specified absolute coordinate system from the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid bodies relative to the specified reference point, and the accelerations of the specified reference point in the specified absolute coordinate system; the step of sequentially determining the angular velocities of the corresponding parts of the respective rigid bodies based on data from a time series of deviation angles of the corresponding parts of the corresponding rigid bodies; the step of sequentially determining the calculated positions of the point of application of the reaction force of the support of each leg in the indicated biped walking moving body based on at least the angle of deviation of the thigh of the specified leg or the angle of flexion of the knee joint of the specified leg as the corresponding parts of the rigid body of the specified biped walking moving body; and the step of evaluating the moment acting on at least one of the joints of each leg of the indicated biped walking moving body based on the inverse dynamics model using the calculated values of the indicated support reaction force, the calculated position of the indicated application point of the support reaction force, the accelerations of the centers of gravity of the corresponding parts corresponding rigid bodies and angular velocities of said respective parts of corresponding rigid bodies in said absolute coordinate system, deviation angles corresponding x parts of the respective rigid bodies, predetermined masses and sizes of the corresponding parts of the respective rigid bodies, the positions of the predetermined centers of gravity of the corresponding parts of the rigid body in the corresponding parts of the respective rigid bodies, and the predetermined moments of inertia of the corresponding parts of the respective rigid bodies.

If, as described above, the second stage in the aforementioned method for evaluating the support reaction force provides for a corresponding measurement of the deflection angle of the body, then the bending angles of the hip joint and knee joint of each leg and the acceleration of the reference point of the biped walking moving body in the absolute coordinate system must be measured again to determine the position of the center of gravity of a bipedal walking moving body relative to a reference point and so on. In addition, the rigid body coupling model may be similar to the rigid body coupling model used to determine the center of gravity of a bipedal walking moving body and so on.

In the method for estimating the moment corresponding to the present invention, as described above, by measuring the angle of deviation of the body and the flexion angles of the hip joints and knee joints, respectively, it is possible to obtain from the measurement data the deviation angles of the corresponding parts of the corresponding rigid bodies (they represent the mutual postural dependence of the corresponding parts of the corresponding rigid bodies), such as the body, hips, legs, and so on, of a two-legged walking moving body. In this case, based on the masses of the corresponding parts of the corresponding rigid bodies, the positions of the centers of gravity of the corresponding parts of the rigid body in the corresponding parts of the corresponding rigid bodies (in particular, the positions of the corresponding parts of the rigid body in the coordinate system fixed relative to the corresponding parts of the rigid bodies) and the deflection angles of the corresponding of the parts of the corresponding rigid bodies, it seems possible to determine the positions of the centers of gravity of the corresponding parts of the corresponding rigid bodies respect to a reference point. In addition, the acceleration of the center of gravity of each corresponding part of the rigid body relative to the reference point is obtained as a second-order differential value of the position of the center of gravity, which is obtained from the data of the time series of the positions of the center of gravity, thus, by measuring the acceleration of the reference point in the absolute coordinate system, it can be obtained acceleration of the center of gravity of each corresponding part of the rigid body of a two-legged walking moving body in the absolute coordinate system as complex (total) acceleration of the acceleration of the center of gravity relative to the reference point and acceleration of the reference point (acceleration in the absolute coordinate system).

In addition, the angular velocity of each corresponding part of the rigid body is obtained as a differentiated second-order value of the deflection angle, which is determined from the data of the time series of deflection angles of each corresponding part of the rigid body.

In accordance with the knowledge of the authors of this application, the position of the point of application of the reaction force of the support of each leg in a bipedal walking moving body, for example, the position of the point of application of the reaction force of the support of each leg relative to the ankle of the foot, has a close correlation with the angle of deviation of the thigh of each leg as the corresponding part of the bipedal walking body moving body, and the angle of flexion of the knee joint of each leg. Thus, it is possible to obtain the estimated position of the point of application of the reaction force of the support in the bipedal walking moving body based on at least the angle of deviation of the thigh of each leg and the angle of flexion of its knee joint.

In this case, if the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid bodies of the bipedal walking moving body, the angular velocities of the corresponding parts of the corresponding rigid bodies and the calculated position of the point of application of the support reaction force are obtained as described above, it is possible to evaluate the moments acting on the knee the joint and hip joint of each leg based on the well-known so-called reverse dynamics model using those data and so on together with the calculated values and the reaction forces of the support obtained using the aforementioned method for evaluating the reaction force of the support. In short, a technique based on this inverse dynamics model uses the equation of motion for the center of gravity transfer of the corresponding part of each rigid body of a bipedal walking moving body and the equation of motion for the rotation motion of the corresponding part of the rigid body (for example, the rotation motion around the center of gravity of the corresponding part of the rigid body) and makes it possible to obtain moments acting on the corresponding joints of a biped walking walking body, corresponding to the corresponding pose (s) of a rigid body link model, in order from the joint closest to the point of application of force of the floor reaction. Although the details will be described later, assuming that, for example, each leg is a connected body having a hip and lower leg as corresponding parts of a rigid body, respectively, the force (joint reaction force) acting on the knee joint of the leg can be obtained by applying acceleration the center of gravity of the lower leg, the calculated value of the reaction force of the support acting on the legs, and the mass of the lower leg in the equation of motion for the movement of the center of gravity of the lower leg of each leg. In addition, the moment of the knee joint of the leg can be estimated by applying the reaction force of the support acting on the knee joint of the leg, the angular velocity of the leg of the leg, the estimated position of the point of application of the reaction force of the leg support, the estimated value of the reaction force to the legs, data values related to the center position the severity of the lower leg in the lower leg and the size (length) of the lower leg, the moment of inertia of the lower leg, the value of the angle of deviation of the lower leg in the equation of motion for the motion of rotation of the lower leg.

In addition, the joint reaction force acting on the hip joint of the leg can be obtained by applying acceleration of the center of gravity of the thigh, the reaction force of the joint acting on the knee joint of the leg, and the value of the mass of the thigh in the equation of motion of the transfer of the center of gravity of the thigh. In addition, the moment on the hip joint of the leg can be estimated by applying the reaction forces of the joint, respectively, acting on the knee joint and hip joint of the leg, the angular velocity of the hip of the leg, data values related to the position of the center of gravity of the thigh in the thigh and the size (length) of the thigh , and the hip deflection angle in the equation of motion for the hip rotation movement.

According to the moment estimation method according to the present invention, as described above, by evaluating the moments acting on the leg joints using the calculated support reaction force values obtained by the aforementioned support reaction force estimation method according to the present invention, it seems relatively easy to evaluate in real time, the moments acting on the joints of the leg without mounting relatively large sensors and so on to the bipedal walking moving body.

Brief Description of the Drawings

Figure 1 is a schematic diagram provided to explain the basic principle of a method for evaluating the reaction force of a support according to the present invention.

Figure 2 is a schematic illustration of a person as a bipedal walking moving body and the composition of devices attached to a person, in one embodiment of the present invention.

Figure 3 is a block diagram shown to explain the functions of the arithmetic processor provided in the devices illustrated in figure 2.

FIG. 4 is a diagram illustrating a rigid body communication model used in data processing of the arithmetic processor illustrated in FIG. 3.

5 is a diagram illustrating the correlation between the components of the forward direction of the vector of the point of application of the reaction force of the support and the angle of deviation of the thigh during normal walking.

6 is a diagram illustrating the correlation between the components of the vertical direction of the vector of the point of application of the reaction force of the support and the angle of deviation of the thigh during normal walking.

7 is a diagram illustrating the correlation between the components of the forward direction vector of the point of application of the support reaction force and the angle of flexion of the knee joint when sitting on a chair.

Fig. 8 is a diagram illustrating the correlation between the components of the forward direction vector of the point of application of the reaction force of the support and the angle of flexion of the knee joint when rising from a chair.

9 is a diagram illustrating the correlation between the components of the forward direction of the vector of the point of application of the reaction force of the support and the angle of the deviation of the thigh when climbing the stairs.

Figure 10 is a diagram illustrating the correlation between the components of the forward direction of the vector of the point of application of the reaction force of the support and the angle of the deflection of the thigh when descending down the stairs.

11 is a diagram for explaining data processing in the arithmetic processor illustrated in FIG. 3, designed to evaluate the moment of the joint.

12 is a graph illustrating the state of temporary changes in the calculated values of the reaction forces of the support during normal walking, which are obtained using an embodiment of the present invention.

13 is a graph illustrating the state of temporary changes in the calculated values of the reaction forces of the support when climbing stairs, which are obtained using an embodiment of the present invention.

Fig. 14 is a graph illustrating the state of temporary changes in the calculated values of the support reaction forces when standing up from a chair, which are obtained using an embodiment of the present invention.

Fig is a graph illustrating the state of temporary changes in the calculated values of the moments acting on the knee joint and hip joint, which are obtained using an embodiment of the present invention.

Detailed Description of a Preferred Embodiment of the Present Invention

One embodiment will be described with reference to the aforementioned FIGS. 1 and 2-10.

The present embodiment is an embodiment in which a method for evaluating a support reaction force and a moment estimating method according to the present invention are applied to a person who is an example of a two-legged walking moving body.

Figure 2 shows as an example an illustration of man 1, on which, in accordance with the approximate classification of his structure, a man has a pair of legs 2, 2 (left and right leg), a trunk 5 containing a waist 3 and a chest 4, a head 6 and a pair hands 7, 7 (left and right hand). Waist 3 is connected to the corresponding legs 2, 2 through a pair of hip joints 8, 8 (left and right), so that the trunk 5 is supported on both legs 2, 2. In addition, the chest 4 of the trunk 5 is located on the upper side of the waist 3 so so as to freely deviate to the front of man 1 relative to the waist 3. And finally, the arms 7, 7 extend from both left and right side parts of the upper chest 4, and the head 6 is supported on the upper end of the chest 4.

Each of the legs 2, 2 has a hip 9 extending from the hip joint 8, and a shin 11 extending from the tip of the hip 9 through the knee joint 10, and the foot 13 is connected to the end part of the leg 11 through the ankle (ankle joint) 12.

In the present embodiment of the present invention, to assess the reaction force of the support acting on each leg 2 of a person 1 having the structure described above, and to further evaluate the moments acting on the knee joint 10 and the hip joint 8, the person 1 is equipped with the following devices.

In particular, a gyro sensor 14 (hereinafter referred to as the chest gyro sensor 14) is mounted on the chest 4 of the body 5, which generates output signals corresponding to the angular velocity of the deflection of the chest 4, an acceleration meter 15 (referred to below as the chest acceleration meter 15 in the forward-backward direction ), which generates output signals corresponding to the acceleration of the chest 4 in the forward-backward direction, the arithmetic processor 16, comprising a central processor, random access memory, th storage device, and so on, and a battery 17 serving as a power source for the arithmetic processor 16 and so on. In this case, these devices: a chest gyro sensor 14, a chest acceleration meter 15 in the forward-backward direction, an arithmetic processor 16 and a battery 17 are placed, for example, in a receiving element 18, made in the form of a satchel, which is mounted on the chest 4 with using a belt or similar fastener (not shown), and unitarily attached to the chest 4 through the receiving element 18.

The acceleration represented by the outputs of the chest acceleration meter 15 is more specifically acceleration in the forward and backward direction in the horizontal section of the chest 4 (in the direction perpendicular to the central axis of the chest 4). In the state in which person 1 stands straight (vertically) on a flat platform, it is acceleration in the horizontal direction (in the direction of the X axis of the absolute coordinate system, as illustrated in FIG. 2) back and forth, while in the state in which the waist 3 or the chest 4 deviates from the vertical direction (the Z axis direction of the absolute coordinate system, as illustrated in FIG. 2), it is an acceleration in the direction deviated relative to the horizontal direction by the angle of the chest deflection 4 relative but vertical direction.

In addition, the gyro sensor 19 (hereinafter referred to as the waist gyro sensor 19) for generating output signals corresponding to the angular velocity of the deflection of the waist 3, an acceleration meter 20 (referred to as the front and back waist acceleration meter 20) for generating output signals corresponding to the acceleration waist 3 in the front-back direction, and an acceleration meter 21 (hereinafter referred to as the waist acceleration meter 21 in the up-down direction) for generating output signals, respectively vuyuschih waist acceleration in the up-down unitarily mounted / fixed to the body 5 of the waist 3 through fastening means such as a belt (not shown).

In this case, the waist acceleration meter 20 in the front-back direction, more specifically, is a sensor similar to the chest acceleration meter 15 in the front-back direction, designed to detect acceleration in the front-back direction in the direction of the horizontal section of the waist 3 (in the direction perpendicular the central axis of the waist 3). In addition, the waist-up acceleration meter 21 is more specifically a sensor for detecting the up-down acceleration in the direction of the center axis of the waist 3 (i.e., perpendicular to the acceleration detected by the waist-acceleration meter 20 in the front-back direction) . Incidentally, the waist acceleration meter 20 in the front-back direction and the waist acceleration meter 21 in the up-down direction can be unitarily formed as a biaxial acceleration meter.

In addition, on the hip joint 8 and knee joint 10 of each leg 2, a sensor 22 of the angles of the hip joint and a sensor 23 of the angles of the knee joint are mounted, which generate output signals corresponding to the relative bending angles Δθc and Δθd. As for the sensors 22 of the angles of the hip joint, although Fig. 2 shows only the sensor 22 of the angles of the hip joint related to the hip joint of 8 legs 2 on this side (the right side of the person 1 is facing forward), on the hip joint 8 of the legs 2 on the other side (the left side of the person 1 is facing back) a sensor of 22 angles of the hip joint is mounted, tolerably with a sensor of 22 angles of the hip joint on this side.

These angle sensors 22 and 23 are formed, for example, by potentiometers and attached to each leg 2 through, for example, a tape element (not shown). In this case, the bending angle Δθc detected by each sensor 22 of the angles of the hip joint, more specifically, is the angle of rotation of the hip 9 of the leg 2 around the hip joint 8 (around the central axis of the hip joint in the left-right direction of the person 1) relative to the waist 3, when used in as a criterion of a condition in which a postural relationship between the waist 3 and the thigh of the leg 2 is given (for example, a postural relationship in which the central axis of the waist 3 and the central axis of the thigh 9 become essentially pairs allelic when person 1 is upright). Similarly, the bending angle Δθd detected by each knee angle sensor 23 is the angle of rotation of the lower leg 11 around the knee joint 10 (around the central axis of the knee joint 10 in the left-right direction of person 1) relative to the hip 9, when used as a condition criterion , in which a postural relationship between the thigh 9 and the lower leg 11 of the leg 2 is specified (for example, a postural dependence in which the central axis of the thigh 9 and the central axis of the lower leg 11 become substantially parallel to each other).

Incidentally, the above-mentioned respective sensors 14, 15 and 19-23 are connected to the arithmetic processor 16 via signal lines (not shown) for inputting output signals (sensors) to the arithmetic processor 16.

As illustrated in FIG. 3, the aforementioned arithmetic processor 16 is provided with functionality. In particular, the arithmetic processor 16 is provided with means 24 for assessing the movement of the legs, designed to assess whether the state of movement of the legs 2, 2 of the person is a state of one position (the state illustrated in figure 1 (a)) or a state of two positions (state illustrated in FIG. 1 (b)), using the detection data of the waist acceleration meter 21 in the up-down direction and the calculated reaction force value of the support of each leg 2 obtained using the later described means 36 for evaluating the reaction force supports. In addition, the arithmetic processor 16 is provided with means 25 for measuring chest deflection angles for measuring chest deflection angle θa 4 in the absolute coordinate system Cf (specifically, the deflection angle θa relative to, for example, the vertical direction; see FIG. 2) , using the detection data of the chest acceleration meter 15 in the forward and backward direction and the chest gyro sensor 14, and with the means 26 for measuring the waist deviation angles intended to measure the angle θb from the deviation of the waist 3 in the absolute coordinate system Cf (specifically, the deviation angle θb relative to, for example, the vertical direction; see FIG. 2), using the detection data of the waist acceleration meter 20 in the front-back direction and the waist gyro sensor 19.

Incidentally, the arithmetic processor 16 is provided with means 27 for measuring the reference acceleration intended to obtain acceleration (acceleration of displacement) a ₀ = ^T (a ₀ x, a ₀ z), in the absolute coordinate system Cf, the coordinate origin of the coordinate system Cp of the body (xz coordinates, as shown in FIG. 2), which is set on the waist 3 as the reference point of person 1 in the present embodiment of the present invention, as illustrated in FIG. 2, using the detection data of the forward acceleration meter 20 red-back and the waist acceleration meter 21 in the up-down direction and the waist deflection angle data θb 3, measured by means 26 for measuring the waist deflection angle. In this case, the body coordinate system Cp is more specifically a coordinate system (a coordinate system whose directions of three axes are similar to the directions of the above-mentioned absolute coordinate system Cf), in which the origin of coordinates O is set, for example, at the midpoint of the line connecting the corresponding centers left and right hip joints 8, 8 of a person 1, the direction of the z axis is set in the vertical direction, and the direction of the x axis is set in the horizontal direction of the forward moving person and 1.

In addition, the arithmetic processor 16 is provided with means 28 for calculating the position of the legs, designed to obtain the angles θc and θd of deviation relative to the hip 9 and lower leg 11 of each leg 2 in the absolute coordinate system Cf (in particular, the angles θc and θd of the deviation relative to, for example, vertical direction; see FIG. 2), using the detection data of the sensor 22 of the angles of the hip joint and the sensor 23 of the angles of the knee joint of the leg 2 and the data of the angle θb of the deflection of the waist 3 obtained using the aforementioned means 26 for and measuring the angle of deviation of the waist.

In addition, the arithmetic processor 16 is provided with means 29 for calculating the position of the center of gravity of the corresponding part, designed to determine the positions of the centers of gravity of the corresponding parts of the corresponding rigid body (in particular, the positions of the centers of gravity in the aforementioned body coordinate system Cp) of the person 1 corresponding to the model described later connection of rigid bodies, using the data of the angle of deflection of the chest 4, angle of deflection 3 of the waist 3, angle 9 of the hip 9 and angle of the deflection and 11 of each leg 2 obtained using the aforementioned means 25 for measuring the angle of deviation of the chest, means 26 for measuring the angle of deviation of the waist and means 28 for calculating the position of the legs: with means 30 for calculating the position of the center of gravity of the body, intended to obtain the position of the center of gravity total person 1 in the aforementioned system of coordinates of the body coordinates, using these positions of the centers of gravity of the corresponding parts of the corresponding rigid body: with means 31 for calculating the position of the ankle, designated for - using position data G0 center of gravity of the person 1 (see Figure 1; referred to below as the body’s center of gravity G0) and data on the corresponding deflection angles θc and θd of the hip 9 and lower leg 11 of each leg 2 using the aforementioned means 28 for calculating the position of the leg — the position of the ankle 12 of each leg 2 as a specific part of each leg 2 in the present embodiment relative to the center of gravity G0 of the body (in particular, ΔX, ΔZ, ΔXr and ΔZr in the above equations (5)); and with the means 32 for calculating the acceleration of the center of gravity of the body, designed to determine the acceleration a = ^T (ax, az) (see Fig. 1) of the center of gravity G0 in the absolute coordinate system Cf using the position of the center of gravity of the body obtained using the above means 30 for calculating the position of the center of gravity of the body, and the acceleration data a _{0 of the} origin 0 of the coordinates of the coordinate system Cp of the body coordinates obtained using the means 27 for measuring the reference acceleration.

In addition, the arithmetic processor 16 is provided with means 33 for calculating the acceleration of the corresponding part of the leg, designed to determine the accelerations (accelerations of displacement) of the centers of gravity of the thigh 9 and lower leg 11 of each leg 2 in the absolute coordinate system Cf, using these positions of the centers of gravity of the corresponding parts of the corresponding the rigid body of a person 1 (in particular, the provisions of the centers of gravity of the corresponding parts of the rigid body related to each leg 2) obtained using the above means 29 To calculate the position of center of gravity of the corresponding part, and data of the acceleration a ₀ of the origin O of the coordinate system Cp body coordinate obtained by the aforementioned means 27 for measuring the reference acceleration: with a means 34 for calculating the angular velocity of the respective leg, intended to determine the angular velocity of the thigh 9 and lower leg 11 of each leg 2 in the absolute coordinate system Cf, using data on the corresponding angles θc and θd of the deviation of the thigh 9 and lower leg 11 of leg 2 obtained using the aforementioned tool and 28 to calculate the position of the feet; and with means 35 for evaluating the point of application of the reaction force, designed to assess the position of the point of application of the reaction force of the support of each leg 2, touching the ground, using the data of the angle of deviation θc hip 9 obtained using the above means 28 for calculating the position of the legs, and the angle θd flexion of the knee joint 10, measured using the aforementioned sensor 23 angles of the knee joint.

In addition, the arithmetic processor 16 is provided with a support reaction force estimator 36 for estimating a support reaction force acting on each leg 2 using the acceleration data of the body center of gravity obtained using the above-mentioned means 32 for calculating the acceleration of the center of gravity body, data of the position of the ankle 12 of each leg 2 relative to the center of gravity of the body, obtained using the above-mentioned means 31 for calculating the position of the ankle, and data on the result of judging the state of motion ia legs 2, 2 obtained using the aforementioned means 24 for assessing leg movement; and with means 37 for evaluating the moment of the joint, designed to assess the moments acting on the knee joint 10 and the hip joint 8, respectively, of each leg 2, using data on these calculated values of the reaction force of the support, data of accelerations of the centers of gravity of the thigh 9 and lower leg 11 each leg 2 obtained using the aforementioned means 33 for calculating the acceleration of the corresponding part of the leg, the data of the angular velocities of the thigh 9 and lower leg 11 of each leg 2 obtained using the above means 34 for calculating the angular soon the corresponding part of the leg, the data of the estimated position of the point of application of the support reaction force obtained by the above-mentioned means 35 for estimating the point of application of the reaction force of the support, and the angles θc and θd of the deviation of the hip 9 and lower leg 11, respectively, of each leg 2 obtained from using the aforementioned means 28 for calculating the position of the legs.

Now, the operation of this embodiment will be described together with more detailed data processing contents of the corresponding means of the aforementioned arithmetic processor 16.

In the present embodiment of the present invention, if the person 1 turns on the power supply switch (not shown) of the arithmetic processor 16 in a state in which both legs 2, 2 touch the support (floor), for example, when moving legs 2, 2, for example, when walking , then the data processing by the arithmetic processor 16 is performed in sequence for a predetermined cycle time, as will be described below, in order to subsequently receive the calculated values of the reaction forces of the support and so on acting on each leg 2.

In particular, the arithmetic processor 16 first performs data processing of the aforementioned means 24 for estimating the movement of the leg. When processing the data of the means 24 for estimating the movement of the leg, the detection data of the acceleration of the waist 3 in the upward direction obtained by the aforementioned measuring instrument 21 of the acceleration of the waist in the up-down direction is compared with a predetermined threshold value determined in advance for the aforementioned cycle time. In this case, if the detected acceleration value exceeds the threshold value, then it is believed that the state of two positions begins, as illustrated in the above drawing of Fig. 1 (b), while the state of one position, as shown in Fig. 1 (a), ends . In particular, when moving from a state of one position to a state of two positions during walking of a person 1, touching the foot 2 of the side of the free foot of the floor (support) causes the waist 3 near the hip joints 8 to generate substantially higher acceleration (acceleration that cannot be generated) in the normal state of one position). Thus, by comparing the detection data of the acceleration of the waist 3 in the upward direction obtained by the measuring tool 21 of the acceleration of the waist in the up-down direction with a predetermined threshold value, as described above, the aforementioned means 24 for assessing the movement of the legs determines the beginning of the state of two positions and the end state of one position.

In addition, when processing the means 24 for assessing the movement of the legs of the calculated values of the support reaction forces Ft and Fr (see Fig. 1 (b)) acting on both legs 2, 2, respectively, which are obtained in the state of two positions using the means 35 for estimates of the point of application of the support reaction force, as will be described later, the calculated value of the support reaction force Fr = ^T (Frx, Frz) (in particular, the absolute value = √ (Frx ² + Frz ² ) of the support reaction force Fr obtained during the previous cycle arithmetic processor 16) acting on leg 2 on the back side relative to directions of a person’s forward movement are compared with a predetermined threshold value (a positive value of approximately “0”) determined in advance. In this case, if the absolute value of the calculated value of the support reaction force Fr falls to a threshold value or lower, then it is assumed that the state of two positions ends and the state of one position begins. In the present embodiment, the initial state of the state of movement of the legs 2, 2 is a state of two positions, and the means 24 for evaluating the movement of the legs considers that the state of the movement of the legs 2, 2 is a state of two positions until the calculated value of the reaction force of the support acting on each of legs 2, 2, will not drop to the above threshold value or less.

In parallel with the processing of the data of the means 24 for estimating the movement of the legs, as described above, the arithmetic processor 16 performs data processing using the aforementioned means 25 for measuring the angles of the chest and means 26 for measuring the angles of the waist. In this case, when processing the data of the means 25 for measuring the angles of chest deflection, the chest deflection angle θa 4 in the absolute coordinate system Cf is obtained sequentially for the duration of the previous cycle in accordance with the known method using data processing of the so-called Kalman filter based on the detection of chest acceleration cells 4 in the forward-backward direction and angular velocity of the chest 4, which are injected from the chest acceleration meter 15 back and forth and the chest sensor 14 Christmas trees, respectively. Similarly, when processing the data of the means 25 for measuring the angle of the waist deviation, the waist deflection angle θb 3 in the absolute coordinate system Cf is obtained sequentially using the processing of the Kalman filter data based on the detection data of the acceleration of the waist 3 in the forward-backward direction and the angular velocity of the waist 3, which are introduced from the meter 20 acceleration of the waist in the front-back direction and gyro sensor 19 of the waist, respectively. In this case, in the present embodiment of the present invention, the angles θa and θb of the deflection of the chest 4 and waist 3, respectively, in the absolute coordinate system Cf are the deflection angles relative to, for example, the vertical direction (direction of gravity).

It is also possible to obtain the deflection angles of the chest 4 and waist 3, for example, by integrating the angular velocity detection data by means of gyro sensors 14 and 19. However, as in the present embodiment, the deflection angles θa and θb of the chest 4 and waist 3 can be accurately measured using Kalman filter data processing.

In this case, the arithmetic processor 16 performs data processing of the aforementioned means 28 for calculating the position of the legs and data processing of the aforementioned means 27 for measuring the reference acceleration.

When processing the data using the aforementioned means 28 for calculating the position of the leg, the deviation angles θc and θd (deviation angles with respect to the vertical direction; see FIG. 2) of the hips 9 and lower legs 11 of each leg 2 in the absolute coordinate system Cf are obtained for the aforementioned cycle time as follows. In particular, the hip deflection angle θc of each leg 2 is calculated from the current time value of the flexion angle detection information Δθc of the hip joint 8 by means of the aforementioned hip joint angle sensor 22 attached to the leg 2 and the current value of the waist deflection angle θb of the waist 3 obtained by the aforementioned means 25 for measuring the deflection angles of the waist, using the following equation (6).

In this case, the deviation angle θb of the waist 3 assumes a negative value if the waist 3 is deviated relative to the vertical direction so that the upper end part of the waist 3 protrudes in front of the person 1 in comparison with its lower end part, and the flexion angle Δθc of the hip joint 8 takes a positive value, if the thigh 9 is deflected relative to the central axis of the waist 3 so that the lower end part of the thigh 9 projects forward of person 1.

In addition, the leg deflection angle θd of the lower leg 11 of each leg 2 is calculated from the current time value of the hip deflection angle θc obtained in the manner described above and the current time value of the bend angle detection information Δθd of the knee joint 10 obtained by the aforementioned knee angle sensor 23 attached to the leg 2, using the following equation (7).

In this case, the bending angle of the knee joint 10 takes a positive value if the lower leg 11 deviates relative to the central axis of the thigh 9 to the back of the thigh 9.

In addition, when processing the data of the aforementioned means 27 for measuring the reference acceleration, the acceleration a ₀ = ^T (a ₀ x, a ₀ z) of the coordinate origin of the aforementioned body coordinate system Cp in the absolute coordinate system Cf is obtained as follows. In particular, if it is given that the current time value of the detection data of the acceleration of the waist 3 in the forward-backward direction by the aforementioned measuring instrument 20 of the acceleration of the waist in the front-backward direction is ap, and the current time value of the data of the detection of the acceleration of the waist 3 in the up-down direction by the aforementioned of the waist acceleration meter 21 in the up and down direction is equal to aq, then the acceleration a ₀ = ^T (a ₀ x, a ₀ z) in the absolute coordinate system Cf is obtained from the detection data ap and aq and the current angle θb from the deviation of the waist 3 obtained by the aforementioned means 25 for measuring the angle of deviation of the waist, using the following equation (8).

In this case, the arithmetic processor 16 performs data processing of the aforementioned means 29 for calculating the position of the center of gravity of the corresponding part and determines the position (position relative to the origin of the coordinate system Cp of the body coordinates) of the centers of gravity of the corresponding parts of the corresponding rigid bodies of the person 1 in the aforementioned system of Cp coordinates of the body when using the model communication of rigid bodies described below.

As shown in FIG. 4, the rigid body coupling model R used in the present embodiment of the present invention is a model that expresses (represents) person 1 by binding together the rigid bodies R1, R1 corresponding to the hips 9 of the corresponding both legs, rigid bodies R2 , R2 corresponding to lower legs 11, 11, rigid body R3 corresponding to waist 3, and rigid body R4 corresponding to part 38 (referred to below as upper part 38 of the body) in a combination of the above chest 4, bodies 7, 7 of the arm and head 6. B in this case, the part is mutually tie between each rigid body R1 and the rigid body R3 and the relationship between the part rigid body R1 and the rigid body R2 correspond to the hip joint 8 and the knee joint 10, respectively. In addition, part of the relationship between the rigid body R3 and the rigid body R4 is part 39 of the center of the hinge for the chest 4 relative to the waist 3.

In the present embodiment, the positions of the centers of gravity G1, G2, G3 and G4 of the corresponding rigid bodies (hips 9 and lower legs 11 of each leg 2, waist 3 and upper body 38) of a person 1 corresponding to rigid bodies R1-R4 of such a rigid body communication model R in the corresponding parts of the respective rigid bodies, recorded in advance and stored in the memory (not shown) of the arithmetic processor 16.

In this case, the positions of the centers of gravity G1, G2, G3 and G4 of the corresponding parts of the respective rigid bodies, recorded / stored in the arithmetic processor 16, are the positions in the coordinate system, which is fixed relative to the corresponding part of each rigid body. In this case, as data representing each of the positions of the centers of gravity G1, G2, G3 and G4 of the corresponding parts of the respective rigid bodies, for example, the distance in the direction of the central axis of the corresponding part of the rigid body from the central point of the joint at one end part of such corresponding part is used hard body. In particular, for example, as shown in FIG. 4, the position of the center of gravity G1 of each hip 9 is given as the position with a distance t1 in the direction of the central axis of the hip 9 from the center of the hip joint 8 of the hip 9, the position of the center of gravity G2 of each lower leg 11 is given as position c the distance t2 in the direction of the central axis of the lower leg 11 from the center of the knee joint 10 of the lower leg 11, and the values of these distances t1 and t2 are obtained in advance and recorded / stored in the arithmetic processor 16. This also applies to the positions of the centers of gravity G3, G4 of other corresponding parts th rigid body.

Strictly speaking, the position of the center of gravity G4 of the upper body 38 is influenced by the movements of the arms 7, 7 that make up the upper body 38. However, due to the fact that the arms 7, 7 during walking generally occupy a symmetrical relative position relative to the central axis of the chest 4, the position of the center of gravity G4 of the upper body 38 does not change much and essentially corresponds, for example, to the position of the center of gravity G4 of the upper body parts 38 in a state of direct (vertical) position.

In addition, in the present embodiment, in addition to data representing the positions of the centers of gravity G1, G2, G3 and G4 of the corresponding parts of the rigid bodies (hip 9 and lower leg 11 of each leg 2, waist 3 and upper body 38), arithmetic processor 16 is predetermined and mass data of the corresponding parts of the respective rigid bodies and data on the sizes of the corresponding parts of the respective rigid bodies (for example, data on the lengths of the corresponding parts of the respective rigid bodies) are recorded / stored.

The mass of the leg 11 is the mass including the foot 13 ((approx. Per.) Mass of the foot). In addition, data previously recorded / stored in the arithmetic processor 16, as described above, can be obtained by actual measurement or the like, or can be obtained by calculation from the height and mass of person 1 based on statistics of a normal person. In general, the positions of the centers of gravity G1, G2, G3 and G4, the masses and sizes of the above-mentioned corresponding parts of the corresponding rigid bodies correlate with the height or weight of the person, and based on this correlation, the positions of the centers of gravity G1, G2, G3 and G4 can be estimated relatively accurately , masses and sizes of the aforementioned corresponding parts of the respective rigid bodies from data on the height and weight of a person.

The above-mentioned means 29 for calculating the position of the center of gravity of the corresponding part determines the position of the centers of gravity G1, G2, G3 and G4 of the corresponding parts of the corresponding rigid bodies in the body coordinate system Сp (coordinates x, z in FIG. 4) having the coordinate origin O fixed on the waist 3, from previously recorded / stored in the arithmetic processor 16, as described above, the current time values of the chest deflection angle θa 4 (= upper body deflection angle 38) and waist deflection angle θb obtained using the above medium 25 for measuring the angle of deviation of the chest and means 26 for measuring the angle of deviation of the waist, respectively, and the current time values of the angles θc and θd of the deviation of the thigh 9 and lower leg 11, respectively, of each leg 2, obtained using the aforementioned means 28 for calculating the position of the leg .

In this case, since the deflection angles θa-θd of the corresponding parts of the corresponding rigid bodies (hips 9 and lower legs 11 of each leg 2, waist 3 and upper body 38) are obtained as described above, the positions and postures of the corresponding parts of the corresponding rigid bodies in the body coordinate system Cp, the deviations and data on the dimensions of the corresponding parts of the corresponding rigid bodies can be determined from the data of the angles θa-θd Thus, the positions of the centers G1, G2, G3 and G4 of the corresponding parts of the corresponding rigid bodies are determined in the body coordinate system Cp.

In particular, for example, with reference to FIG. 4, with respect to the leg 2 located on the left side of FIG. 4, since the angle of deviation of the hip 9 in the body coordinate system CP (the angle of deviation relative to the direction of the z axis) is θc (in this case, θc < 0, as shown in Fig. 4), then the coordinates of the position of the center of gravity center G1 of the hip 9 with the coordinate system Cp of the body become (t1 · sinθc, -t1 · cosθc). On the other hand, since the angle of deviation of the lower leg 11 in the body coordinate system Ср is equal to θd (θd <0, as shown in Fig. 4) and it is given that the length of the thigh 9 is Lc, the coordinates of the position of the center of gravity G2 of the lower leg 11 in the coordinate system С bodies become (Lc · sinθc + t2 · sinθd, -Lc · cosθc-t2 · cosθd). The centers of gravity of the thigh 9 and lower leg 11 of the other leg 2, waist 3 and upper body 38 can be defined in the same way as described above.

After determining the positions of the centers of gravity G1, G2, G3 and G4 of the corresponding parts of the respective rigid bodies in the body coordinate system Cp using the means 29 for calculating the position of the center of gravity of the corresponding part, as described above, the arithmetic processor 16 performs data processing of the aforementioned means 30 for calculating the position the center of gravity of the body and determines the position (Xg, zg) of the center G0 of the body’s gravity in the body coordinate system Cp using these positions of the centers of gravity G1, G2, G3 and G4 of the corresponding parts, respectively existing bodies and given masses of the corresponding parts of the corresponding rigid bodies.

In this case, it is given that the position of the center of gravity G3 of the waist 3 in the body coordinate system CP and its mass are (x3, z3) and m3, respectively, the position of the center of gravity G4 of the upper body 38 in the body coordinate system CP and its mass are (x4 , z4) and m4, respectively, the position of the center of gravity center G1 of the thigh 9 legs 2 on the left side of the person 1, facing forward, in the CP coordinate system of the body and its mass are (x1L, z1L) and m1L, respectively, the position of the center of gravity center G2 of the lower leg 11 of the same leg in the CP coordinate system of the body and its mass are (x2L, z2L) and m2L, respectively, the position of the center of gravity G1 of the thigh 9 legs 2 on the right side in the body coordinate system CP and its mass are (x1R, z1R) and m1R, respectively, the position of the center of gravity center G2 of the tibia 11 of the same leg in the body coordinate system CP and its mass are (x2R , z2R) and m2R, respectively, and the mass of person 1 is M (= m1L + m2L + m1R + m2R + m3 + m4), and the position (Xg, zg) of the person’s center of gravity G0 in the body coordinate system Cp is determined using the following equations (9).

After processing the data of the means 30 for calculating the position of the center of gravity of the body, as described above, the arithmetic processor 16 further performs the data processing of the above means 32 for calculating the acceleration of the center of gravity of the body and processing the data of the above means 31 for calculating the position of the ankle.

In this case, when processing the data of the means 32 for calculating the acceleration of the center of gravity of the body, first when using the data of the time series of positions (Xg, zg) of the center of gravity G0 of the body in the body coordinate system Cp obtained by means of 30 for calculating the position of the center of gravity of the body on the time of the preceding cycle, a differentiated second-order value of the position (Xg, zg) of the body’s center of gravity G0 in the body coordinate system CP is determined, that is, the acceleration ^T (d ² xg / dt ² , d ² zg / dt ² ) of the body’s gravity center G0 relative to the beginning About the coordinates of the system CPco nate body. In this case, by determining the vector sum of the acceleration ^T (d ² xg / dt ² , d ² zg / dt ² ) and the acceleration a ₀ = ^T (a ₀ x, a ₀ z) determined using the above-mentioned means 27 for measuring the reference accelerations, the origin of the coordinates of the body coordinate system Cp in the absolute coordinate system Cf determine the acceleration a = ^T (ax, az) of the body's center of gravity G0 in the absolute coordinate system Cf.

In addition, when processing data of the aforementioned means 31 for calculating the position of the ankle, at the beginning of the current time values of the angles θc and θd of the deviation of the thigh 9 and lower leg 11, respectively, of each leg 2, obtained using the aforementioned means 28 for calculating the position of the leg, values the current time of the data of the angle of deviation of the waist θb obtained using the aforementioned means 26 for measuring the angle of deviation of the waist, and data on the size (length) of the thigh 9 and ankle 11, determine the position of the ankle 12 of each leg 2 in the above bodily coordinate system Cp by processing similar to the aforementioned data processing means 29 for calculating the position of center of gravity of the respective parts. In particular, with reference to FIG. 4 with respect to the leg 2 located on the left side of FIG. 4, it is given that the length of the lower leg 11 (the length from the center of the knee joint 10 to the ankle 12) is Ld, with coordinates (x12, z12) of the position of the ankle 12 in the body coordinate system Cp, they become (Lc · sinθc + Ld · sinθd, -Lc · cosθc-Ld · cosθd) (where θc <0 and θd <0), as shown in FIG. 4. This also applies to the other leg 2.

In this case, the current time values of the position data (x12, z12) of the ankle 12 in the body coordinate system CP and the position (Xg, zg) of the center of gravity G0 in the body coordinate system CP obtained using the aforementioned means 30 for calculating the position of the body's center of gravity are determined the radius vector ^T (x12-xg, z12-zg) of the ankle 12 of each leg 2 relative to the center of gravity G0 of the body, i.e., ΔXf, ΔZf, ΔXr and ΔZr in the above equations (5).

In this case, the arithmetic processor 16 performs data processing of the aforementioned means 36 for estimating the reaction force of the support as follows. In particular, in this data processing, if the state of movement of the legs 2, 2, determined using the aforementioned means 24 for evaluating the movement of the legs, during the current cycle is a state of one position, then the calculated value of the reaction force F = ^T (Fx, Fz) is obtained the support acting on the foot 2, touching the ground, from the values of the mass M and acceleration g of the gravity of the person 1 (they are stored in the arithmetic processor 16) and the values of the current acceleration time a = ^T (ax, az) of the center of gravity G0 of the body in the absolute system Cf coordinates obtained using the above of the means 32 for calculating the acceleration of the center of gravity of the body, using the above equation (2). In this case, the reaction force of the support acting on the leg 2, not touching the ground (free leg 2), is ^T (0, 0).

On the other hand, if the state of movement of the legs 2, 2, determined using the aforementioned means 24 for assessing the movement of the legs, during the current cycle is a state of two positions, then the calculated values of the forces Ff = ^T (Ffx, Ffz) and Ff = ^T ( Frx, Frz), respectively, of the reaction of the support acting on the legs 2, from the values of the mass M and the acceleration g of the person’s gravity 1, the values of the current acceleration time a = ^T (ax, az) of the body’s center of gravity G0 in the absolute coordinate system Cf obtained using the aforementioned means 32 for calculating the acceleration of the center of gravity ate, and the data of the values of the current time of the position of the ankle 12 of each leg 2 relative to the center G0 of gravity of the body (the values of the current time of the data on ΔXf, ΔZf, ΔXr and ΔZr in the above equations (5)) obtained using the aforementioned ankle position calculator using the above equation (5).

On the other hand, in parallel with the data processing, the means 30 for calculating the position of the center of gravity of the body, the means 32 for calculating the acceleration of the center of gravity of the body, the means 31 for calculating the position of the ankle and the means 36 for evaluating the reaction force of the support, as described above, the arithmetic processor 16 performs data processing the aforementioned means 33 for calculating the acceleration of the corresponding part of the leg, means 34 for calculating the angular velocity of the corresponding part of the leg, and means 35 for estimating the point of application of the support reaction force.

In this case, when processing the data of the aforementioned means 33 for calculating the acceleration of the corresponding part of the leg, at the beginning it is similar to the aforementioned means 32 for calculating the acceleration of the center of gravity of the body, using data from the time series of the positions of the centers of gravity G1 and G2 of the thigh 9 and lower leg 11, respectively, which are the corresponding parts of each leg 2 in the body coordinate system Cp, which are obtained using the aforementioned means 29 for calculating the position of the center of gravity of the corresponding part for the time preceding of the second cycle, differential values of the second order of the positions of the centers of gravity of the thigh 9 and lower leg 11, respectively, are obtained in the body coordinate system Сp, that is, the acceleration (acceleration relative to the origin О of the coordinate system of the body coordinate system Сp) of the corresponding center of gravity of the hip 9 and lower leg 11 in the CP coordinate system of the body. In this case, by obtaining the vector sum of these corresponding accelerations and accelerations a ₀ = ^T (a ₀ x, a ₀ z) of the waist 3 in the absolute coordinate system Cf using the aforementioned means 27 for measuring the reference acceleration, accelerations (more specifically, coordinate acceleration components in the absolute coordinate system Cf) of the thigh 9 and lower leg 11, respectively, in the absolute coordinate system Cf.

In addition, when processing the data of the aforementioned means 34 for calculating the angular velocity of the corresponding part of the leg, using the data of the time series of the angles θc and θd of the deviation of the thigh 9 and lower leg 11, respectively, of each leg 2, obtained using the aforementioned means 28 for calculating the position of the legs at the time of the previous cycle, differential values of the second order of the angles θc and θd of the deviation of the thigh 9 and lower leg 11, respectively, that is, the angular velocities of the thigh 9 and lower leg 11, respectively, are obtained.

In addition, when processing data of the means 35 for estimating the point of application of the support reaction force with respect to the foot 2 touching the ground, a vector (radius vector of the application of the reaction force of the support relative to the ankle 12; hereinafter referred to as the vector of the application point of the support reaction force) from the ankle is determined 12 feet 2 to the point of application of the reaction force of the support of the foot 13 of the foot 2 (the point at which the total reaction force of the support acting on the part of the foot 13 touching the ground is considered concentrated) is obtained as data representing the position of the application point with support reaction arms, for example, from the current time value of the hip deflection angle θc obtained using the aforementioned leg position calculating means 28 based on a predetermined correlation, as shown in FIG. 5 and FIG. 6.

In particular, in accordance with the knowledge of the authors of this application, the angle of deviation of the thigh 9 or the angle Δθd of bending of the knee joint 10 of the leg 2 touching the ground has a relatively large correlation with the point of application of the support reaction force. The aforementioned support point reaction force application point vector, in particular, the components of the support reaction force application point vector in the forward direction (X axis direction) of the person 1, and the support reaction force application point vector vector in the vertical direction (Z axis vector), respectively, change depending, for example, on the angle θc deviation of the thigh 9, as shown in Fig.5 and Fig.6. In this case, the negative deflection angle θc of the hip 9 is the angle if the hip 9 is deflected relative to the central axis of the waist 3 so that the foot 2 extends to the back of the person 1 (for example, foot 2 on the right side of the person 1 facing forward in FIG. 2) while the positive angle θc is the angle if the hip 9 is deflected relative to the central axis of the waist 3 so that the leg 2 is on the front side of the person 1 (for example, leg 2 on the left side of the person 1 facing forward in FIG. 2).

Thus, in the present embodiment, approximate expressions using the hip deflection angle θc of 9 as a parameter that represents the correlations illustrated in FIGS. 5 and 6 are obtained and pre-recorded and stored in the arithmetic processor 16. In this case, when processing the data of the aforementioned means 35 for estimating the point of application of the support reaction force, the value of the current time of the hip deflection angle θc obtained using the aforementioned leg position calculating means 28 is substituted into the aforementioned approximate expression, in accordance with this vector to obtain the above-mentioned force application points of floor reaction (particularly, the components of the application point of the floor reaction force in the X direction and in the direction of the axis of the axis Z).

In this case, in the correlations illustrated in FIGS. 5 and 6, in which the hip deflection angle θc has a minimum value, even at the same hip deflection angle θc, the value of the support reaction force application point vector differs between the step of decreasing the deflection angle θc and the stage its increase. Thus, in the present embodiment, upon receipt of the aforementioned approximate expression, the transition of the aforementioned correlation from the landing of the heel of the foot 13 to the floor (to the support) for removing the tips of the toes from the support is classified in the first phase (phase a1 in FIG. 5; phase b1 in FIG. 6), in which the angle of deviation θc of the thigh 9 is positive, the second phase (phase a2 in FIG. 5; phase b2 in Fig.6), in which the angle θc of deviation of the hip 9 is negative, and the rate of change of the angle of deviation θc, i.e. the angular velocity of the hip deflection 9, which is negative, and in the third phase (phase a3 in Fig. 5; phase b3 in Fig. 6), in which the angle of deviation of the hip is θc and the angular velocity of the deviation of the hip 9 is positive, and these phases are approximated by a similar function or other functions relative to the components of the direction of the X axis and the components of the direction of the Z axis of the vector of the point of application of the support reaction force, respectively. The approximate expression of the phase in the combination of the first and second phases a1 and a2 in the correlation of Fig. 5, if it is given that the components of the direction of the axis of the vector of the point of application of the support reaction force are px, are expressed, for example, by a sixth-order polynomial function in the form

px = x ₁ · θc ⁶ + x ₂ · θc ⁵ + x ₃ · θc ⁴ + x ₄ · θc ³ + x ₅ · θc ² + x ₆ · θc + x ₇

(where x ₁ -x ₇ are constant values).

In addition, the approximate expression of the third phase a3 in the correlation of Fig. 5 is expressed, for example, by a fourth-order polynomial function in the form

px = x ₈ · θc ⁴ + x ₉ · θc ³ + x ₁₀ · θc ² + x ₁₁ · θc + x ₁₂

(where x ₈ -x ₁₂ are constant values).

In addition, the approximate expression of the phase in the combination of the first and second phases b1 and b2 in the correlation of FIG. 6, if it is given that the components of the direction of the Z axis of the point of application of the support reaction force are pz, are expressed, for example, by a sixth order polynomial function in the form

pz = z ₁ · θc ⁶ + z ₂ · θc ⁵ + z ₃ · θc ⁴ + z ₄ · θc ³ + z ₅ · θc ² + z ₆ · θc + z ₇

(where z ₁ -z ₇ are constant values).

In addition, the approximate expression of the third phase b3 in the correlation of Fig.6 is expressed, for example, by a polynomial function of the third order in the form

pz = z ₈ · θc ³ + z ₉ · θc ² + z ₁₀ · θc + z ₁₁ (where z ₈ -z ₁₁ are constant values).

In this case, when determining the vector of the point of application of the reaction force of the support, it is determined whether the angle of deviation of the hip 9 is positive or negative, and it is further determined whether the angular velocity of the hip calculated by differentiating the first order of the time series data of the angle of deviation of the hip 9 is positive or negative. In addition, from a certain positive or negative angle θc and a certain positive or negative angular velocity of deviation, it is determined which phase is currently being manifested, and by substituting the current time of the angle of deviation θc of the hip 9 into the approximate expression of the estimated phase, the point of application of the reaction force is calculated supports. In accordance with this, the magnitude of the vector of the point of application of the force of support of the support at the stage of decreasing the angle θc of deviation of the hip 9 and the magnitude of the vector of the point of application of the force of the reaction of support at the stage of increasing it can be discriminated.

In the present embodiment, the correlation between the deflection angle θc of the hip 9 of the leg and the support force reaction point vector is approximated by polynomials so as to obtain the support reaction force application point vector. However, it is also possible to record / store the correlations illustrated in FIGS. 5 and 6 in the form of a data table, and when using the data table, to obtain the vector of the support reaction force application point from the hip deflection angle θc 9.

In addition, the position of the point of application of the support reaction force also has a correlation with the bending angle of the knee joint 10 of the leg 2 touching the ground. Thus, the position of the point of application of the support reaction force can be determined from the bending angle Δθd of the knee joint 10, measured by the knee angle sensor 23, instead of the hip deflection angle θc 9. In an alternative embodiment, using both the hip deflection angle θc 9 and the bending angle Δθd of the knee 10, the position of the point of application of the support reaction force can be estimated using a map or the like.

In addition, if person 1 sits on a chair or rises from a chair from a sitting position, then the correlation illustrated in Fig. 7 (when sitting on a chair) or in Fig. 8 (when rising from a chair) is established between the position of the point of application of the reaction force the support and the angle Δθd of bending the knee joint 10, and when climbing or descending the stairs, Fig. 9 (when climbing the stairs) or Fig. 10 (when lowering the stairs), a correlation is established between the position of the point of application of the reaction force of the support and the deviation angle θc hips 9. So, when sitting on while standing or getting up from a chair, the position of the point of application of the reaction force of the support from the angle Δθd of bending of the knee joint 10 can be estimated based on the correlation illustrated in Fig. 7 or Fig. 8, whereas when climbing stairs or lowering the stairs, the position of the point of application of the reaction force the support can be estimated from the angle θc deviation of the thigh 9 based on the correlation illustrated in Fig.9 or Fig.10.

In this case, after evaluating the position of the point of application of the reaction force, as described above, the arithmetic processor 16 performs data processing of the aforementioned means 37 for estimating the joint moment and obtains the moments acting on the knee joint 10 and the hip joint 8 of each leg 2. This data processing is carried out based on the so-called reverse dynamics model, using the current time values of the data, respectively obtained using the aforementioned means 36 for assessing the reaction force of the support, means 33 for calculating For accelerating the corresponding part, means 34 for calculating the angular velocity of the corresponding part of the leg, means 35 for estimating the point of application of the reaction force of the support, and means 28 for calculating the position of the leg. This reverse dynamics model uses the equation of motion for the transport movement of each corresponding part of the rigid body of a person 1 and the equation of motion for the movement of its rotation in order to obtain the moments acting on the joints properly from the joint closer to the point of application of the support reaction force. In the present embodiment, the moments acting on the knee joint 10 and the hip joint 8 of each leg 2 are obtained appropriately.

More specifically, as follows from Fig. 11, at the beginning, with regard to the lower leg 11 of each leg 2, the force (reaction force of the joint) acting on the ankle 12 at the tip of the lower leg 11, the force (reaction force of the joint) acting on part of the knee joint 10 of the leg 11, and the acceleration of the transfer of the center of gravity G2 of the leg 11, respectively, are given as ^T (F ₁ x, F ₁ z), ^T (F ₂ x, F ₂ z) and ^T (a ₁ x, a ₁ z) in in accordance with the designation system of the components in the absolute coordinate system Cf, and the mass of the leg 11 is given as m ₂ . In this case, the following equation (10) becomes the equation of motion of the transfer of the center of gravity of the lower leg 11.

^T (m ₂ · a ₂ x, m ₂ · a ₂ z) = ^T (F ₁ xF ₂ x, F ₁ zF ₂ zm ₂ · g).

Hence,

In this case, the acceleration ^T (a ₂ x, a ₂ z) of the center of gravity G2 of the lower leg 11 is obtained using the means 33 for calculating the acceleration of the corresponding part of the leg. In addition, the joint reaction force ^T (F ₁ x, F ₁ z) acting on the ankle 12 at the tip of the lower leg 11 is approximately equal to the calculated value of the support reaction force obtained using the aforementioned means 36 for assessing the reaction force of the support for leg 2 having drumstick 11. More specifically, in a single position, if leg 2 is on the ground, then the joint reaction force ^T (F ₁ x, F ₁ z) is the force ^T (Fx, Fz) of the support reaction obtained by the above equation (2) , and if foot 2 is a free foot, then ^T (F ₁ x, F ₁ z) = ^T (0, 0). On the other hand, in a two-position state, if leg 2 is a foot on the back of person 1 facing forward in the forward direction, then the joint reaction force ^T (F ₁ x, F ₁ z) is the reaction force ^T (Fx, Fz) support of the above equations (5), and if leg 2 is a foot of the front side, then it is the reaction force ^T (Ffx, Ffz) of the support of the above equations (5).

Thus, the force ^T (F ₂ x, F ₂ z) of the joint reaction acting on the knee joint 10 of each leg 2 is determined from the acceleration data ^T (a ₂ x, a ₂ z) of the center of gravity G2 of the lower leg 11 obtained by means of 33 to calculate the acceleration of the corresponding part of the leg, data on the support reaction force ^T (F ₁ x, F ₁ z) obtained by means of 36 for evaluating the reaction force of the support, the leg mass data mz obtained in advance, and the gravity acceleration value g, using the above equation (10).

In addition, as follows from Fig. 11, it is given that the moment acting on the ankle 12 at the tip of the lower leg 11 is M ₁ , the moment acting on the part of the knee joint 10 of the lower leg 11 is equal to M ₂ , the moment of inertia around the center of gravity G2 of the lower leg 11 is equal to I _G2 , and the angular velocity around the center of gravity G2 of the lower leg is α ₂ . In addition, it is given that in accordance with the above figure 4, the distance between the center of gravity G2 of the lower leg 11 and the center of the knee joint 10 is t ₂ , and the distance between the center of gravity G2 of the lower leg 11 and the ankle 12 is t ₂ '(= Ld-t ₂ ), and the equation of motion for the motion of rotation around the center of gravity G2 of the lower leg becomes the following equation (11).

I _G2 · α ₂ = M ₁ -M ₂ + F ₁ x · t ₂ '· cosθd-F ₁ z · t ₂ ' · sinθd + F ₂ x · t ₂ · cosθd-F ₂ z · t ₂ · sinθd.

Hence,

In this case, M ₁ in equation (11) is the moment obtained as the vector product of the point of application of the reaction force of the support obtained by the aforementioned means 35 for estimating the point of application of the reaction force of the support with respect to the leg 2 having the lower leg 11 related to the equation (11) and the floor reaction force vector produced by the above means 36 to estimate the floor reaction force with respect to the leg 2. α ₂ is the angular velocity of the crus 11 determined by the above means 34 to calculate the angular Scabbers the corresponding part of the foot. θd is the deflection angle of the lower leg 11 determined by the aforementioned means 28 for calculating the position of the leg. ^T (F ₁ x, F ₁ z) is, as described above, the calculated value of the support reaction force obtained by the aforementioned means 36 for evaluating the support reaction force. In addition, ^T (F ₂ x, F ₂ z) is obtained using the above equation (10). The moment I _{G2 of} inertia is determined in advance and stored in the arithmetic processor 16 together with the data of mass m ₂ and the size of the lower leg 11 and so on.

Thus, the moment M ₂ acting on the knee joint 10 is obtained from the data of the calculated value of the support reaction force obtained by means 36 for estimating the support reaction force, the data of the support reaction force application point vector obtained by means 35 for evaluating the application point the reaction force of the support, the data of the angular velocity α _{2 of the} lower leg 11 determined using the means 34 for calculating the angular velocity of the corresponding part of the leg, the data of the angle θd of the deviation of the lower leg 11 determined using the means 28 for calculating the position of the leg, joint reaction force data ^T (F ₂ x, F ₂ z) obtained using the aforementioned equation (10) and inertia moment I _G2 , size Ld and t ₂ position t _{2 of} gravity center G2 11 obtained in advance using the above equation ( eleven).

After receiving the moment M ₂ acting on the part of the knee joint 10 of the lower leg 11, as described above, the means 37 for estimating the moment of the joint in accordance with data processing similar to the processing of the data for calculating the moment of the knee joint calculates the moment acting on the part of the hip joint 8 of the thigh 9 The main idea of this data processing is similar to the technique for obtaining the moment M _{2 of the} knee joint 10, and thus, there is no need for a detailed illustration and explanation thereof. Below are its main principles.

In particular, at the beginning, the joint reaction force ^T (F ₃ x, F ₃ z) is obtained, acting on the part of the hip joint 8 of the hip 9, using the following equation (12) (an equation of the same form as the above equation (10)), based on the equation of motion for the motion of the center of gravity transfer G1 (see figure 4) of the hip 9.

In this case, the force ^T (F ₂ x, F ₂ z) is the reaction force of the knee joint 10, previously obtained using the above equation (10). The acceleration ^T (a ₁ x, a ₁ z) is the acceleration (transfer acceleration) of the center of gravity G1 of the hip 9 in the absolute coordinate system Cf, which is obtained using the above-mentioned means 33 for calculating the acceleration of the corresponding part of the leg. In addition, the mass m ₁ is the mass of the thigh 9 obtained in advance, and g is the acceleration of gravity.

In this case, the moment M ₃ is obtained, acting on the part of the hip joint of the thigh 9, using the following equation (13) based on the equation of motion for the rotation around the center of gravity G1 of the thigh 9.

In this case, M ₂ is the moment of the knee joint 10 obtained using the above equation (11), the force ^T (F ₂ x, F ₂ z) is the reaction force of the knee joint 10 obtained using the above equation (10), the force ^T ( F ₃ x, F ₃ z) is the reaction force of the hip joint 8 obtained using the above equation (12), I _G2 is the moment of inertia around the center of gravity G1 of the thigh 9 obtained in advance, the angular velocity α ₁ is the angular velocity of the thigh 9 obtained using the aforementioned means 34 for calculating the angular velocity awns corresponding leg, and θs is the angle of deflection of the thigh 9, obtained via the aforementioned means 28 for calculating the position of the legs. In addition, the distance t ₁ is the distance from the center of the hip joint 8 to the center of gravity G1 of the thigh 9 (see FIG. 4), and the distance t ₁ 'is the distance from the center of the knee joint 10 to the center G1 of the gravity of the thigh 9 (Lc-t ₁ on 4), which are determined based on the position of the center G1 of gravity and the size (length) of the thigh 9 obtained in advance.

The data processing described above is sequentially performed for the cycle time of the aforementioned arithmetic processor 16, so that the support reaction force acting on each leg 2 and the moments acting on the knee joint 10 and the hip joint 9 of each leg 2 are sequentially evaluated in real time .

Although this application does not provide a detailed description, the calculated values of the moments acting on the knee joints 10 and hip joints 8 are used to control, for example, a device that promotes walking of a person 1 (the device contains electric motors or similar actuators, which can apply auxiliary torques to the knee joints 10 and the hip joints 8).

The states of temporary changes in the calculated values of the support reaction forces (in particular, the absolute values of the calculated values of the support reaction forces) obtained by the above-mentioned data processing of the arithmetic processor 16 are shown in Figs. 12-14 by solid lines. In addition, the state of temporary changes in the calculated values of the moments on the knee joint 10 and the hip joint 8 obtained by processing the data of the arithmetic processor 16 are shown in Fig. 15 by solid lines. In this case, FIG. 12 and FIG. 15 are illustrations in which person 1 is walking on a flat platform at substantially constant speed, FIG. 13 is an illustration in which person 1 is walking up the stairs, and FIG. 14 an illustration is shown in which person 1 rises from a state of sitting on a chair. 12-14, dotted lines also illustrate comparative examples (corresponding to the true values of the support reaction forces) obtained by actually measuring the reaction forces of the support using a force meter or similar measuring device. In addition, FIG. 15 also shows comparative examples (corresponding to the true values of the moments on the knee joint 10 and the hip joint 8), obtained by actually measuring the moments on the knee joint 10 and the hip joint 8 using a torque meter or a similar measuring device. .

12-14, it becomes apparent that in accordance with the present invention, the exact calculated values of the reaction forces of the support are obtained regardless of the type of movement of the environment of the legs 2. In addition, in the present embodiment, as shown in FIG. 15, moments on the knee joint 10 and the hip joint 8 can also be estimated with relatively high accuracy using the calculated support reaction forces.

As described above, in accordance with this embodiment, it is possible to simply evaluate in real time the reaction force of the support acting on the hip joint 8 and knee joint 10 of each leg 2, using relatively small and light sensors, for example, sensors 22 and 23, attached to the hip joints 8 and knee joints 10, respectively, and gyro sensors 14 and 19 and meters 15, 20 and 21 attached to the body 5, without the attachment of such sensors to the legs 2, as this prevents walking or çäàåò load leg movement 2. In addition, such an assessment may be made with relatively high accuracy irrespective of the motion type or motion environment of legs 2, that is, whether there is a person on the flatland, whether the ladder is raised, and so on.

In the embodiment described above, the description was given for a case taken as an example in which the present invention is applied to human 1. However, the present invention also applies to a biped walking robot, taken as a biped walking walking body. Here, in the case of a bipedal walking robot, it can have a structure in which the waist and chest are made as one unit. In this case, it is possible to attach the gyro sensor and the acceleration meter in the forward-backward direction to the waist or chest and evaluate the reaction forces of the support and the moments on the joints of the legs in the same way as in the present embodiment. In addition, in the case of a bipedal walking robot, it also seems possible to determine the bending angles of the hip joints and knee joints based on the control values of the controller for the actuators of these joints.

In the aforementioned embodiment, the detection data of the waist acceleration meter 21 in the up and down direction is used to assess the state of movement of the legs 2. However, instead of such detection data, for example, the acceleration components a0 of the waist 3 in the vertical direction (in the Z-axis direction) in the absolute system can be used Cf coordinates that are obtained using the aforementioned means 27 for measuring reference acceleration.

Industrial applicability

As described above, the present invention is useful in facilitating walking or regulating the walking of a bipedal walking moving body, such as a person or a robot, while support reaction forces and joint moments acting on the legs of the moving body can be determined.

Claims (9)

1. A method of evaluating the reaction force of the support acting on each of the legs of a bipedal walking moving body, comprising a first step in evaluating whether the state of movement of the legs of the biped walking body is a state of one position in which only one of the legs touches the ground, or a state of two positions in which both legs touch the ground; the second stage of sequentially determining the positions of the center of gravity of the indicated biped walking moving body and sequentially determining the accelerations of the specified center of gravity in the absolute coordinate system fixed relative to the ground by using data from a time series of the positions of the specified center of gravity; a third step of sequentially determining the positions of a particular part with respect to the indicated center of gravity in at least two states in the indicated state, said specific part being predetermined in the vicinity of the lower end part of each leg; the step of obtaining the calculated values of the indicated reaction force of the support acting on the foot touching the ground, sequentially, in the state of one position of the indicated biped walking moving body based on the equation of motion for the specified center of gravity, expressed using mass and acceleration of gravity of the biped walking walking body, acceleration the specified center of gravity and the indicated reaction force of the support acting on the foot touching the ground; the step of obtaining the calculated values of the indicated reaction forces of the support acting on both legs, sequentially, in the state of two positions of the specified biped walking moving body based on the equation of motion for the specified center of gravity, expressed using mass and acceleration of gravity of the biped walking walking body, acceleration of the specified center the severity and the indicated reaction forces of the support acting on both legs, and the expression of the relationship between the position of the specified specific part of each leg relative to the specified center STI and said floor reaction force acting on said leg, said expression is determined depending on the assumption that said floor reaction force acting on each leg body acts from said specific portion of said leg to said center of gravity. 2. The method according to claim 1, wherein said specific part of each leg is an ankle of said leg. 3. The method according to claim 1, further comprising the step of measuring acceleration in the up-down direction of the lower body supported on both legs by the hip joint of each leg, said lower body being located near said hip joints, wherein the movements of said bipedal walking moving body are evaluated so that if the acceleration of said lower body in the up-down direction increases to a predetermined threshold value or more, then the specified state of two positions is determined, while the state of one position ends, and if the calculated value of the indicated reaction force of the support acting on the leg, which is going to make a separation, decreases to a predetermined threshold value or less in the specified state of two positions, then the specified state of two positions ends , while the indicated state of one position begins. 4. The method according to claim 1, further comprising the step of appropriately measuring the angle of deviation of the body supported on both legs by the hip joint of each leg, the bending angles of at least the hip joint and knee joint of each leg, and accelerating the predetermined reference point of the indicated bipedal walking body in the specified absolute coordinate system in which at the specified second stage, based on the angle of deviation of the specified body, the bending angles of the specified hip joints and the specified track joints, a rigid body coupling model formed by representing the indicated biped walking walking body as a connected body from a plurality of rigid bodies, predetermined masses of the corresponding parts of the corresponding rigid body of the biped walking walking body, corresponding to the corresponding rigid bodies of the specified rigid body coupling model, and positions, predefined centers of gravity of the corresponding parts of the rigid body in the corresponding parts of the corresponding rigid body, the positions of the center of gravity of the indicated biped walking moving body relative to the indicated reference point are determined, the accelerations of the specified center of gravity relative to the indicated reference point are successively determined based on the time series of the positions of the specified center of gravity, and the acceleration of the specified center of gravity in the specified absolute coordinate system is determined from the acceleration of the specified center gravity relative to the specified reference point and the acceleration of the specified reference point in the specified absolute system coordinates. 5. The method according to claim 4, in which the specified reference point is installed on the specified body. 6. The method according to claim 4, in which the specified body has a waist associated with both legs through the hip joints, and a chest located on the waist so as to deviate from the specified waist, and the angle of deviation of the specified body used to determine the position of the specified center severity, contains the angles of deviation of the waist and chest. 7. The method according to claim 6, in which the specified model of the connection of rigid bodies is a model representing the lower leg located on the lower side of the knee joint of each leg of a bipedal walking moving body, the hip between the specified knee joint and the specified hip joint, the specified waist and upper body located on the upper side of the specified waist and including the specified chest, as rigid bodies. 8. A method for evaluating the moment acting on at least one joint of each leg of a bipedal walking moving body by using the calculated values of the reaction force of the support on each leg, sequentially determined using the method according to claim 1, comprising a step of appropriately measuring a body deflection angle supported on both legs by a hip joint of each leg, bending angles of at least a hip joint and a knee joint of each leg, and accelerating a predetermined reference point of the indicated biped walking moving body in the indicated absolute coordinate system; the step of sequentially determining the deflection angles of the corresponding parts of the corresponding rigid body of the bipedal walking moving body, corresponding to the corresponding rigid bodies of the specified rigid body coupling model, based on the deflection angle of the specified body, the bending angles of the indicated hip joint and the specified knee joint of each leg and the rigid body coupling model, formed by representing the indicated two-legged walking moving body as a coherent body of many rigid bodies; the step of sequentially determining the positions of the centers of gravity of the corresponding parts of the corresponding rigid body relative to the indicated reference point based on the deflection angles of the indicated corresponding parts of the corresponding rigid body, the predetermined masses of the corresponding parts of the corresponding rigid body and the positions of the predefined centers of gravity of the corresponding parts of the rigid body, in the corresponding parts of the corresponding rigid body and sequential determination of accelerations cent s gravity of the respective rigid-body portions relative to said reference point based on time series data positions corresponding to the centers of gravity corresponding to the rigid body parts: the step of sequentially determining the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid body in the specified absolute coordinate system from the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid body relative to the specified reference point and the accelerations of the specified reference point in the specified absolute coordinate system; the step of sequentially determining the angular velocities of the corresponding parts of the corresponding rigid body based on data from a time series of deviation angles of the corresponding parts of the corresponding rigid body; a step of sequentially determining the calculated positions of the point of application of the reaction force of the support of each leg in the indicated biped walking moving body based on at least the angle of deviation of the thigh of the specified leg and the angle of flexion of the knee joint of the specified leg as the corresponding parts of the rigid body of the specified biped walking moving body and the step of evaluating the moment acting on at least one of the joints of each leg of the indicated biped walking moving body based on the inverse dynamics model using the calculated values of the indicated support reaction force, the calculated position of the indicated application point of the support reaction force, the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid body and angular velocities of the indicated corresponding parts of the corresponding rigid body in the specified absolute coordinate system, deviation angles respectively uyuschih parts corresponding rigid body of predetermined weight and dimensions of the respective parts of the corresponding rigid bodies of predetermined positions corresponding to the centers of gravity of the rigid body portions in the respective parts of the respective rigid-body and the pre-defined moments of inertia of the respective portions corresponding to the rigid body. 9. A method for evaluating the moment acting on at least one joint of each leg of a bipedal walking moving body by using the calculated values of the reaction force of the support on each leg, sequentially determined using the method of claim 4, comprising the step of sequentially determining the deviation angles in the indicated absolute coordinate system of the corresponding parts of the corresponding rigid body of the bipedal walking moving body corresponding to the rigid bodies of the specified rigid body communication model, based on the deflection angle of the specified body, the bending angles of the specified hip joint and the specified knee joint of each leg and the specified rigid body communication models; the step of sequentially determining the positions of the centers of gravity of the corresponding parts of the corresponding rigid body relative to the indicated reference point based on the deflection angles of the indicated corresponding parts of the corresponding rigid body, the predetermined masses of the corresponding parts of the corresponding rigid body and the positions of the centers of gravity of the corresponding parts of the rigid body in the corresponding parts of the corresponding rigid body and sequential determining accelerations of the centers of gravity corresponding to stey appropriate rigid body with respect to said reference point based on time series data corresponding to positions of centers of gravity of the corresponding parts of the rigid body; the step of sequentially determining the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid body in the specified absolute coordinate system from the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid body relative to the specified reference point and the accelerations of the specified reference point in the specified absolute coordinate system; the step of sequentially determining the angular velocities of the corresponding parts of the corresponding rigid body based on data from a time series of deviation angles of the corresponding parts of the corresponding rigid body; the step of sequentially determining the calculated positions of the point of application of the reaction force of the support of each leg in the indicated biped walking moving body based on at least the angle of deviation of the thigh of the specified leg and the angle of flexion of the knee joint of the specified leg as the corresponding parts of the rigid body of the specified biped walking moving body and the step of evaluating the moment acting on at least one of the joints of each leg of the indicated biped walking moving body based on the inverse dynamics model using the calculated value of the indicated support reaction force, the calculated position of the indicated support reaction force application point, the accelerations of the centers of gravity of the corresponding parts of the corresponding rigid body and angular velocities of the indicated corresponding parts of the corresponding rigid body in the specified absolute coordinate system, deviation angles respectively pertinent part a corresponding rigid body of predetermined weight and dimensions of the respective parts of the corresponding rigid bodies of predetermined positions corresponding to the centers of gravity of the rigid body portions in the respective parts of the respective rigid-body and the pre-defined moments of inertia of the respective portions corresponding to the rigid body.

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