CA2043885A1 - Skill developing method - Google Patents
Skill developing methodInfo
- Publication number
- CA2043885A1 CA2043885A1 CA002043885A CA2043885A CA2043885A1 CA 2043885 A1 CA2043885 A1 CA 2043885A1 CA 002043885 A CA002043885 A CA 002043885A CA 2043885 A CA2043885 A CA 2043885A CA 2043885 A1 CA2043885 A1 CA 2043885A1
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- motions
- human body
- model
- segment
- calculating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT OF THE DISCLOSURE
A skill developing Method using dynamics analysis comprises analyzing the basic motions of a human body and inputting the force or torque exerted on each joint into a database, dividing each human body segment from other body segments and calculating the movements of the segments by applying dynamic equations, checking constraints including the articulation of the human body and the range of movements of the joints, calculating the motions and forces produced by the restraints by applying inverse dynamics, calculating the movements of individual segments by applying dynamic equations to develop new motions, checking restraints including the articulation of the human body and the range of movements of each joint, calculating the motions and forces due to the restraints by inverse dynamics, and displaying the motions and the forces.
A skill developing Method using dynamics analysis comprises analyzing the basic motions of a human body and inputting the force or torque exerted on each joint into a database, dividing each human body segment from other body segments and calculating the movements of the segments by applying dynamic equations, checking constraints including the articulation of the human body and the range of movements of the joints, calculating the motions and forces produced by the restraints by applying inverse dynamics, calculating the movements of individual segments by applying dynamic equations to develop new motions, checking restraints including the articulation of the human body and the range of movements of each joint, calculating the motions and forces due to the restraints by inverse dynamics, and displaying the motions and the forces.
Description
2 ~ 3 SKILL DEVELOPING METHO~
BACKGROUND OF THE INVENTION
This invention relates to a skill developing method for analyzing various skills in the industrial and performing arts and forming curricula for teaching the skills.
In order to teach new skills in the industrial and performing arts, it is necessary to analyze the motions involved in the skill and then form curricula for teaching the motions. In the past, an analyst observed the technique of an expert ln the skill to be taught and then formed a teaching curriculum on the basis of his observations. However, because observations are sub~ective, the results may not be reliable.
There has recently been proposed a method wherein a sk~ll ls analyæed using a computer, and a teacher can then use the computer analysis to train an unskilled person to perform the sklll. The computer analysis utilizes kinematics, which describes motions in terms of positions, velocities, and acceleratlons using data which depends upon the sub~ect of analysls. Therefore, only a line picture of the human body can be displayed on a screen, and a three-dimensional model of the human body cannot be displayed reallstically.
Accordingly, it is difficult to understand the display and to develop a new skill using the display.
Furthermore, whlle computer analysls of motions for developing a new skill preferably utilizes a method having real time rcsponse, conventional computer analysis methods have no real time response ~ecause they require the :: , - ' ' ~ '~. ' ;~
.
2~3g8~
ascertainment of the contents of actual motions and fine ad~ustment based on the results.
Another method referred ~o as dynamics provides the motions of an object based on the relation between movements and forces. If dynamics is applied to computer analysis of a skill, it is posslble to generate complex behaYior with minimal control However, motion analysis utilizing dynamics requires data on parameters such as the moments of inertia, the centers of mass, ~oint friction, and muscle/ligament elasticity of the human body, which are difficult to measure.
Without such data, dynamic motion analysis provides unreasonable results similar to those produced by kinematic motion analysis. Furthermore, dynamic motion analysis requires the solvlng of rather complex dynamic equatlons. In the case of an articulated human body with 200 degrses of freedom, 600 simultaneous differential equations must be solved.
Conventional skill analysls by computer utilizing dynamics involves the following steps.
~ 1) Constructing a model of the human body;
(2) Applying the actual motlons of a human to the model;
BACKGROUND OF THE INVENTION
This invention relates to a skill developing method for analyzing various skills in the industrial and performing arts and forming curricula for teaching the skills.
In order to teach new skills in the industrial and performing arts, it is necessary to analyze the motions involved in the skill and then form curricula for teaching the motions. In the past, an analyst observed the technique of an expert ln the skill to be taught and then formed a teaching curriculum on the basis of his observations. However, because observations are sub~ective, the results may not be reliable.
There has recently been proposed a method wherein a sk~ll ls analyæed using a computer, and a teacher can then use the computer analysis to train an unskilled person to perform the sklll. The computer analysis utilizes kinematics, which describes motions in terms of positions, velocities, and acceleratlons using data which depends upon the sub~ect of analysls. Therefore, only a line picture of the human body can be displayed on a screen, and a three-dimensional model of the human body cannot be displayed reallstically.
Accordingly, it is difficult to understand the display and to develop a new skill using the display.
Furthermore, whlle computer analysls of motions for developing a new skill preferably utilizes a method having real time rcsponse, conventional computer analysis methods have no real time response ~ecause they require the :: , - ' ' ~ '~. ' ;~
.
2~3g8~
ascertainment of the contents of actual motions and fine ad~ustment based on the results.
Another method referred ~o as dynamics provides the motions of an object based on the relation between movements and forces. If dynamics is applied to computer analysis of a skill, it is posslble to generate complex behaYior with minimal control However, motion analysis utilizing dynamics requires data on parameters such as the moments of inertia, the centers of mass, ~oint friction, and muscle/ligament elasticity of the human body, which are difficult to measure.
Without such data, dynamic motion analysis provides unreasonable results similar to those produced by kinematic motion analysis. Furthermore, dynamic motion analysis requires the solvlng of rather complex dynamic equatlons. In the case of an articulated human body with 200 degrses of freedom, 600 simultaneous differential equations must be solved.
Conventional skill analysls by computer utilizing dynamics involves the following steps.
~ 1) Constructing a model of the human body;
(2) Applying the actual motlons of a human to the model;
(3) Analyzlng the motions of the model; and ~ 4) Reproducing the analyzed motions.
In the fourth step (reproduclng the analyzed motions), the dynamic equations may be solved exactly. However, this method is not suitable because of its concep~ual and computational complexity, since when n ls the number of segments constituting the human body model and forming the .
, - -- . . . - .
. ,. , , ~ . - ~. : .
-. ~ . - . .
.--. .
2 ~ 8 ~
minimal units of motion in the motion analysis, the number of calculations, i.e., the computational complexity O(f(n)) becomes a function O(n') of n', and thus is very large, so calculation requires a long time.
On the other hand, a method which reduces the computational complexity to O(n) by neglecting rotations of ~oints about the principal axes has been proposed. However, with this method, only a line picture of the parts constituting the human body can be displayed on a screen, and it is not applicable when the rotations of joints about the principal axes cannot be neglected.
SUMMARY OF THE INVENTIO~
It is an ob~ect of this invention to provide a skill developlng method which can analyze the motions of a human using a computer and develop a new skill in an interactive manner without reguiring trial and error or the intuition of an analyst.
In order to achieve the above ob~ect, in a skill developing method of the present invention, the basic motlons of a human body are analyzed to obtain data on dynamic parameters including the forces and torques exerted on ~oints of the human body, and such data are put into a database as knowledge regarding the basic motions.
In order to develop a new sklll, an analyst accesses the database and modifies the data. A computer can provide the analyst with feedback in real time on the result of constraints and on the result of inverse dynamics, and new .
skills can be developed in an interactive manner by repeating the above processes until satisfactory results are obtained.
The computational complexity in this skill developing method is a function O(n) of the number of segments n ln the model, so the computational complexity is greatly reduced.
Furthermore, it is possible to describe realistic motions of the human body using a three-dimensional smooth modeling picture.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a flow chart of a skill developing method according to the present invention.
Figures 2~a) - 2~c) are control graphs for motion design showing an example of the forces exerted on a joint.
Figures 3~a) - 3~l) are schematic views of a display obtalned using dynamics.
Flgures 4~a) - 4~) are schematic view of a display obtained using inverse dynamics.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Flgure 1 ls a flow chart of the method of the present invention. It includes the following steps.
- ~1) Constructing a model of the human body;
~ 2) Applying the actual motions of a human to the model;
~ 3) Analyzing the resulting motions of the model;
~ 4) Developlng new motions from basic motlons;
~ 5) Applying dynamics to the model;
~ 6) Applying constraints to the model;
. : . - - - : ::
- - , . . .
- . .
- : , . , : ' :
., ,:. ~
.. . ~ ~ ~ . . .
- . . . - -' . : -2 ~ 8 ~
(7) Applying inverse dynamics to the model; and ~8) Displaying the result.
In the first step (constructing a model), the human body is divided into a plural~ty of segments connected by joints, each of the segments acting as a minimal unit of motion. A
model then is constructed on the basis of constraints including the nature of each segment, the articulation of the body, and the range of movement of the ioints connecting the segments. Data defininq ~he model are stored in a computer as a database.
In the second step (applying actual motions), a film is taken of the actual motions of'a human~, àhd for each frame of the film, the positions of the body parts of the human are quantified and input to the computer. This data is applied to the model, and the computer calculates the position, velocity, and acceleration of each segment of the model. When the human ls simultaneously filmed from a plurality of directions, the analysis in the next step can be executed more concretely.
In the third step ~analyzing the motions of the model), the motions of the segments determined in the second step are analyzed using inverse dynamics to determine the center of gravity of each body segment, the force and torque exerted on each ~olnt, the position of the center of gravity of the whole body, and the force and torque exerted on the center of gravity of the whole body. When only the analysis of motions i8 deslred, the center of gravity of each body segment, the force and torgue exerted on each joint, the center of gravlty of the whole body, and the force and torque exerted on the '' i-. :. .
--- . ~
' '.': . ' -' ' , ' ` : ' .
- 2~3~8~
center of gravity of the whole body, which are obtained in the third step, are displayed on a screen by arrows or other symbols superimposed on a display of the human body model.
Next, a method for developing a new skill on the basis of the results of the preceding analysis will be explained.
In order to develop a new skill, the data on the human body obtained in the first step, the data on the actual motions of the human body obtained in the second step, and the data on the resul~s of the analysis obtained in the third step are previously input to the database.
In the fourth step (developing new skills), an analyst chooses a plurality of basic motions from the database. ~he basic motions are represented quantitatively by control graphs each showlng the force acting on one of the joints of the model as a function of time. Figures 2(a) - 2(c) are control graphs of the forces acting on the left elbow in the directions of x, y, and z orthogonal axes as a function of time. The two forces exerted on any given ~oint are equal in magnitude and opposite 1n direction. A compllcated motion is represented by a plurality of graphs. The control graphs for motlons of other body segments can be designed ln the same manner as for the illustrated control graphs for the left elbow.
Next, global modlflcatlon and local modlfication of forces are performed. Global modification involves producing a uniform change in forces actlng on all the body segments.
Local modificatlon involves the modification of physical parameters such as the force exerted on a specific segment of - . . :
: . - . . , . .
.
- ~ .
` ' : , : ' ' , ' - ' . -2~3~
the human body.
In the fifth step (application of dynamics), the motion of each body segment is calculated on the basis o~ the forces corresponding to the basic motions selected by the analyst and the dynamic equatlons governing movement of the segments. In this calculation, although the articulation of the human body is essentially as shown in Figure 3(a), each body segment is treated as being separate from the others to reduce the amount of computation, and the constraints on the articulat~on of the human body and the range of movement of joints are neglected for the moment.
In order to calculate the motion of each segment, Newton's e~uation of motion is used to determine the linear acceleration of the center of gravity, and Euler's equations are used to derive the angular acceleration of each segment about its center of gravity. once the linear and angular acceleratlons are obtalned, they are integrated a first tlme to flnd velocitles and integrated a second time to find positions.
In the sixth step ~appllcation of constralnts), the artlculatlon of the human body and the range of the movements of body ~olnts are checked for each of the motions calculated ln the flfth step. The process of applying constralnts starts at a segment referred to as a root segment, and the posltlon and the orlentation of each segment in a subclass of the root segment are checked seguentlally. Here, two types of checks are performed. One is a check whether a subclass segment ls always connected to lts superclass segment. The other ls a 2~3~5 check whether the movement of each joint exceeds a specified range. If the subclass segment is not connected to its superclass segment as shown in Figure 4 (~), the subclass segment is translated until it becomes connected to its superclass segment. If the movement of each segment joint exceeds the specified range, the movement of the joint is ad~usted to be within the range by rotation of the corresponding segment, thus modifying the positions of the segments to obtain a posture as shown in Figure 4~b).
In the seventh step (application of inverse dynamlcs), Lagrange equations which describe the relationship between forces and movement are used to calculate the forces exerted on each ~oint of the body.
If the desired results are not at first obtained, the 5th - 7th steps can be repeated, and the new motlons can be developed in an interactive manner.
In the eighth step (displaying the result), the new motlons whlch have been partially or completely designed are displayed on the screen. The position of the center of gravity of the human body and the direction of forces exerted thereon can be superimposed on the display of the human body.
Furthermore, in the displaying step, the results obtained in the thlrd step in which the motlons of the model are analyzed can also be dlsplayed.
In the present invention, since the sequence ~s executed by a simple line feedback algorithm, the computational complexity of the inverse dynamics becomes a function O(n) of the number of segments n. By using inverse dynamics, a ' ' . ' . ' 2~38~
reasonable and complete combination of forces can be obtained.
In contrast, without lnverse dynamics, it is impossible for the analyst to find the complete dPsign of forces. In the present invention, if the orientation of a body segment is such that the range of movement of either of its joints is exceeded, the orientation of the segment is changed so that the position of the body segment satisfies the physical constraints of the human body. Since the motions of the human body thus obtained are natural motions wherein a subclass segment is always connected to its superclass segment and the movement of each ~oint does not exceed its specified range, such motions can be displayed realistically using a three-dimensional modeling picture.
Furthermore, according to the present invention, it is possible to develop a new motion in an interactive manner uslng a computer without requiring trial and error or the lntu~tion of the analyst.
As mentioned above, the sklll developing method accordlng to the present invention comprises the steps of analyzing the basic motions of an actual human body and developing new motlons. The analysis of the baslc motions of the human body ls achieved in three steps: constructing a human body model, applylng the actual motlons of a human to the model, and analyzlng the motions of the segments of the model. The development of new motlons is achieved in three steps:
appllcatlon of dynamics, application of constraints, and application of inverse dynamics. In the step of applying dynamics, the human body ls divided ~nto a plurallty of _9_ "~
2043~85 independent body segments (50, for example) connected by joints, and the motion of each body segment is calculated independently of the other segments using Newton's equation of motion and Euler's equations. In the step of applying constraints, the articulation of the body and the range of movement of the ~oints are checked. In the step of applying inverse dynamics, the force modified by the constraints and generating new forces are calculated. Thus, the whole computational complexity becomes O(n).
Accordingly, the s~ill developing method according to the present invention can eliminate the computational complexity of conventional methods, it permits dynamics to be applied to actual skill development, and it permits feedback in real time uslng dynamics.
Furthermore, in order to calculate the motions of each segment of the human body, since the linear acceleration of the center of gravlty is calculated using Newton's equation of motlon and the angular acceleration of the center of gravity ls calculated using Euler's equations, it is possible to determlne and display not only the positlon of and the force exerted on the center of gravity of each segment, but also the position of and the force exerted on the center of gravity of the whole human body. In other words, since the position of the center of gravity of the human body and the direction and magnitude of the forces involved in the movement can be displayed, it is possible to easily teach the skill being developed.
It is possible according to the present invention to - . .
.
.
. . .
.
.: : . : . -.. . . . . . . .
- .
2 ~
realistically display the motions of a human body using smooth three-dimenslonal modeling pictures rather than line drawings.
In addition, an analyst can look at the human body model on the screen from various directions, and can translate or rotate various segments of the human body in an interactive manner. Thus, the analyst can ascertain the relationship between the picture and the human body model correctly.
In conventional skill developing methods, basic data on the motions of the human body and the constraints that define the range of movements of individual joints are obtained using the intuition of the analyst. In contrast, in the skill developinq method according to the present invention, actual dynamic parameters are obtained by analyzing the actual motlons of the human body. Accordingly, the motions derived from these parameters are reliable and provide realistic motions.
An ob~ect-oriented paradigm has recently been used in a number of areas. As a user interface, the object-oriented philosophy leads to a direct manipulation paradigm. In this direct manipulation paradigm, since the images displayed on a screen correspond to ob~ects, by using the skill developlng method according to the present invention, the ob~ects can be manipulated directly in the space of the ob~ects.
-, , ... . .
In the fourth step (reproduclng the analyzed motions), the dynamic equations may be solved exactly. However, this method is not suitable because of its concep~ual and computational complexity, since when n ls the number of segments constituting the human body model and forming the .
, - -- . . . - .
. ,. , , ~ . - ~. : .
-. ~ . - . .
.--. .
2 ~ 8 ~
minimal units of motion in the motion analysis, the number of calculations, i.e., the computational complexity O(f(n)) becomes a function O(n') of n', and thus is very large, so calculation requires a long time.
On the other hand, a method which reduces the computational complexity to O(n) by neglecting rotations of ~oints about the principal axes has been proposed. However, with this method, only a line picture of the parts constituting the human body can be displayed on a screen, and it is not applicable when the rotations of joints about the principal axes cannot be neglected.
SUMMARY OF THE INVENTIO~
It is an ob~ect of this invention to provide a skill developlng method which can analyze the motions of a human using a computer and develop a new skill in an interactive manner without reguiring trial and error or the intuition of an analyst.
In order to achieve the above ob~ect, in a skill developing method of the present invention, the basic motlons of a human body are analyzed to obtain data on dynamic parameters including the forces and torques exerted on ~oints of the human body, and such data are put into a database as knowledge regarding the basic motions.
In order to develop a new sklll, an analyst accesses the database and modifies the data. A computer can provide the analyst with feedback in real time on the result of constraints and on the result of inverse dynamics, and new .
skills can be developed in an interactive manner by repeating the above processes until satisfactory results are obtained.
The computational complexity in this skill developing method is a function O(n) of the number of segments n ln the model, so the computational complexity is greatly reduced.
Furthermore, it is possible to describe realistic motions of the human body using a three-dimensional smooth modeling picture.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a flow chart of a skill developing method according to the present invention.
Figures 2~a) - 2~c) are control graphs for motion design showing an example of the forces exerted on a joint.
Figures 3~a) - 3~l) are schematic views of a display obtalned using dynamics.
Flgures 4~a) - 4~) are schematic view of a display obtained using inverse dynamics.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Flgure 1 ls a flow chart of the method of the present invention. It includes the following steps.
- ~1) Constructing a model of the human body;
~ 2) Applying the actual motions of a human to the model;
~ 3) Analyzing the resulting motions of the model;
~ 4) Developlng new motions from basic motlons;
~ 5) Applying dynamics to the model;
~ 6) Applying constraints to the model;
. : . - - - : ::
- - , . . .
- . .
- : , . , : ' :
., ,:. ~
.. . ~ ~ ~ . . .
- . . . - -' . : -2 ~ 8 ~
(7) Applying inverse dynamics to the model; and ~8) Displaying the result.
In the first step (constructing a model), the human body is divided into a plural~ty of segments connected by joints, each of the segments acting as a minimal unit of motion. A
model then is constructed on the basis of constraints including the nature of each segment, the articulation of the body, and the range of movement of the ioints connecting the segments. Data defininq ~he model are stored in a computer as a database.
In the second step (applying actual motions), a film is taken of the actual motions of'a human~, àhd for each frame of the film, the positions of the body parts of the human are quantified and input to the computer. This data is applied to the model, and the computer calculates the position, velocity, and acceleration of each segment of the model. When the human ls simultaneously filmed from a plurality of directions, the analysis in the next step can be executed more concretely.
In the third step ~analyzing the motions of the model), the motions of the segments determined in the second step are analyzed using inverse dynamics to determine the center of gravity of each body segment, the force and torque exerted on each ~olnt, the position of the center of gravity of the whole body, and the force and torque exerted on the center of gravity of the whole body. When only the analysis of motions i8 deslred, the center of gravity of each body segment, the force and torgue exerted on each joint, the center of gravlty of the whole body, and the force and torque exerted on the '' i-. :. .
--- . ~
' '.': . ' -' ' , ' ` : ' .
- 2~3~8~
center of gravity of the whole body, which are obtained in the third step, are displayed on a screen by arrows or other symbols superimposed on a display of the human body model.
Next, a method for developing a new skill on the basis of the results of the preceding analysis will be explained.
In order to develop a new skill, the data on the human body obtained in the first step, the data on the actual motions of the human body obtained in the second step, and the data on the resul~s of the analysis obtained in the third step are previously input to the database.
In the fourth step (developing new skills), an analyst chooses a plurality of basic motions from the database. ~he basic motions are represented quantitatively by control graphs each showlng the force acting on one of the joints of the model as a function of time. Figures 2(a) - 2(c) are control graphs of the forces acting on the left elbow in the directions of x, y, and z orthogonal axes as a function of time. The two forces exerted on any given ~oint are equal in magnitude and opposite 1n direction. A compllcated motion is represented by a plurality of graphs. The control graphs for motlons of other body segments can be designed ln the same manner as for the illustrated control graphs for the left elbow.
Next, global modlflcatlon and local modlfication of forces are performed. Global modification involves producing a uniform change in forces actlng on all the body segments.
Local modificatlon involves the modification of physical parameters such as the force exerted on a specific segment of - . . :
: . - . . , . .
.
- ~ .
` ' : , : ' ' , ' - ' . -2~3~
the human body.
In the fifth step (application of dynamics), the motion of each body segment is calculated on the basis o~ the forces corresponding to the basic motions selected by the analyst and the dynamic equatlons governing movement of the segments. In this calculation, although the articulation of the human body is essentially as shown in Figure 3(a), each body segment is treated as being separate from the others to reduce the amount of computation, and the constraints on the articulat~on of the human body and the range of movement of joints are neglected for the moment.
In order to calculate the motion of each segment, Newton's e~uation of motion is used to determine the linear acceleration of the center of gravity, and Euler's equations are used to derive the angular acceleration of each segment about its center of gravity. once the linear and angular acceleratlons are obtalned, they are integrated a first tlme to flnd velocitles and integrated a second time to find positions.
In the sixth step ~appllcation of constralnts), the artlculatlon of the human body and the range of the movements of body ~olnts are checked for each of the motions calculated ln the flfth step. The process of applying constralnts starts at a segment referred to as a root segment, and the posltlon and the orlentation of each segment in a subclass of the root segment are checked seguentlally. Here, two types of checks are performed. One is a check whether a subclass segment ls always connected to lts superclass segment. The other ls a 2~3~5 check whether the movement of each joint exceeds a specified range. If the subclass segment is not connected to its superclass segment as shown in Figure 4 (~), the subclass segment is translated until it becomes connected to its superclass segment. If the movement of each segment joint exceeds the specified range, the movement of the joint is ad~usted to be within the range by rotation of the corresponding segment, thus modifying the positions of the segments to obtain a posture as shown in Figure 4~b).
In the seventh step (application of inverse dynamlcs), Lagrange equations which describe the relationship between forces and movement are used to calculate the forces exerted on each ~oint of the body.
If the desired results are not at first obtained, the 5th - 7th steps can be repeated, and the new motlons can be developed in an interactive manner.
In the eighth step (displaying the result), the new motlons whlch have been partially or completely designed are displayed on the screen. The position of the center of gravity of the human body and the direction of forces exerted thereon can be superimposed on the display of the human body.
Furthermore, in the displaying step, the results obtained in the thlrd step in which the motlons of the model are analyzed can also be dlsplayed.
In the present invention, since the sequence ~s executed by a simple line feedback algorithm, the computational complexity of the inverse dynamics becomes a function O(n) of the number of segments n. By using inverse dynamics, a ' ' . ' . ' 2~38~
reasonable and complete combination of forces can be obtained.
In contrast, without lnverse dynamics, it is impossible for the analyst to find the complete dPsign of forces. In the present invention, if the orientation of a body segment is such that the range of movement of either of its joints is exceeded, the orientation of the segment is changed so that the position of the body segment satisfies the physical constraints of the human body. Since the motions of the human body thus obtained are natural motions wherein a subclass segment is always connected to its superclass segment and the movement of each ~oint does not exceed its specified range, such motions can be displayed realistically using a three-dimensional modeling picture.
Furthermore, according to the present invention, it is possible to develop a new motion in an interactive manner uslng a computer without requiring trial and error or the lntu~tion of the analyst.
As mentioned above, the sklll developing method accordlng to the present invention comprises the steps of analyzing the basic motions of an actual human body and developing new motlons. The analysis of the baslc motions of the human body ls achieved in three steps: constructing a human body model, applylng the actual motlons of a human to the model, and analyzlng the motions of the segments of the model. The development of new motlons is achieved in three steps:
appllcatlon of dynamics, application of constraints, and application of inverse dynamics. In the step of applying dynamics, the human body ls divided ~nto a plurallty of _9_ "~
2043~85 independent body segments (50, for example) connected by joints, and the motion of each body segment is calculated independently of the other segments using Newton's equation of motion and Euler's equations. In the step of applying constraints, the articulation of the body and the range of movement of the ~oints are checked. In the step of applying inverse dynamics, the force modified by the constraints and generating new forces are calculated. Thus, the whole computational complexity becomes O(n).
Accordingly, the s~ill developing method according to the present invention can eliminate the computational complexity of conventional methods, it permits dynamics to be applied to actual skill development, and it permits feedback in real time uslng dynamics.
Furthermore, in order to calculate the motions of each segment of the human body, since the linear acceleration of the center of gravlty is calculated using Newton's equation of motlon and the angular acceleration of the center of gravity ls calculated using Euler's equations, it is possible to determlne and display not only the positlon of and the force exerted on the center of gravity of each segment, but also the position of and the force exerted on the center of gravity of the whole human body. In other words, since the position of the center of gravity of the human body and the direction and magnitude of the forces involved in the movement can be displayed, it is possible to easily teach the skill being developed.
It is possible according to the present invention to - . .
.
.
. . .
.
.: : . : . -.. . . . . . . .
- .
2 ~
realistically display the motions of a human body using smooth three-dimenslonal modeling pictures rather than line drawings.
In addition, an analyst can look at the human body model on the screen from various directions, and can translate or rotate various segments of the human body in an interactive manner. Thus, the analyst can ascertain the relationship between the picture and the human body model correctly.
In conventional skill developing methods, basic data on the motions of the human body and the constraints that define the range of movements of individual joints are obtained using the intuition of the analyst. In contrast, in the skill developinq method according to the present invention, actual dynamic parameters are obtained by analyzing the actual motlons of the human body. Accordingly, the motions derived from these parameters are reliable and provide realistic motions.
An ob~ect-oriented paradigm has recently been used in a number of areas. As a user interface, the object-oriented philosophy leads to a direct manipulation paradigm. In this direct manipulation paradigm, since the images displayed on a screen correspond to ob~ects, by using the skill developlng method according to the present invention, the ob~ects can be manipulated directly in the space of the ob~ects.
-, , ... . .
Claims (2)
1. A skill developing method comprising:
dividing a human body into a plurality of segments connected by joints, each of the segments acting as a minimal unit of motion, constructing a human body model on the basis of constraints including the inherent future of each segment, the articulation of the body, and the range of the movement of each joint, and inputting the human body model into a database;
applying the actual motions of a human body to the model;
calculating the resulting motions of the model using inverse dynamics and calculating the center of gravity of each segment, the force and torque exerted on each joint, the center of gravity of the whole body, and the force and torque exerted on the center of gravity of the whole body;
choosing a plurality of basic motions from the database, and modifying physical parameters of the basic motions;
calculating the motions of each segment when forces corresponding to the basic motions are applied to the segments using dynamics while neglecting constraints on the articulation of the human body and the range of movements of the joints;
checking and modifying the physical constraints on the articulation of the human body and the range of movements of the joints; and displaying the resulting motions of the human model on a screen.
dividing a human body into a plurality of segments connected by joints, each of the segments acting as a minimal unit of motion, constructing a human body model on the basis of constraints including the inherent future of each segment, the articulation of the body, and the range of the movement of each joint, and inputting the human body model into a database;
applying the actual motions of a human body to the model;
calculating the resulting motions of the model using inverse dynamics and calculating the center of gravity of each segment, the force and torque exerted on each joint, the center of gravity of the whole body, and the force and torque exerted on the center of gravity of the whole body;
choosing a plurality of basic motions from the database, and modifying physical parameters of the basic motions;
calculating the motions of each segment when forces corresponding to the basic motions are applied to the segments using dynamics while neglecting constraints on the articulation of the human body and the range of movements of the joints;
checking and modifying the physical constraints on the articulation of the human body and the range of movements of the joints; and displaying the resulting motions of the human model on a screen.
2. A skill developing method comprising:
dividing a human body into a plurality of segments connected by joints, each of the segments acting as a minimal unit of motion, constructing a human body model on the basis of constraints including the inherent future of each segment, the articulation of the body, and the range of the movement of each joint, and inputting the human body model into a database;
applying actual motions of a human body to the model;
calculating the resulting motions of the model using inverse dynamics and calculating the center of gravity of each segment, the force and torque exerted on each joint, the center of gravity of the whole body, and the force and torque exerted on the center of gravity of the whole body;
choosing a plurality of basic motions from the database, and modifying physical parameters of the basic motions;
calculating the motions of each segment when forces corresponding to the basic motions are applied to the segments using dynamics while neglecting constraints on the articulation of the human body and the range of movements of the joints;
checking and modifying physical constraints on the articulation of the human body and the range of movements of the joints;
calculating the relation between forces and the motions caused by the modification of physical constraints using inverse dynamics; and displaying the result obtained by composing the motions calculated by dynamics and the forces and centers of gravity calculated by inverse dynamics.
dividing a human body into a plurality of segments connected by joints, each of the segments acting as a minimal unit of motion, constructing a human body model on the basis of constraints including the inherent future of each segment, the articulation of the body, and the range of the movement of each joint, and inputting the human body model into a database;
applying actual motions of a human body to the model;
calculating the resulting motions of the model using inverse dynamics and calculating the center of gravity of each segment, the force and torque exerted on each joint, the center of gravity of the whole body, and the force and torque exerted on the center of gravity of the whole body;
choosing a plurality of basic motions from the database, and modifying physical parameters of the basic motions;
calculating the motions of each segment when forces corresponding to the basic motions are applied to the segments using dynamics while neglecting constraints on the articulation of the human body and the range of movements of the joints;
checking and modifying physical constraints on the articulation of the human body and the range of movements of the joints;
calculating the relation between forces and the motions caused by the modification of physical constraints using inverse dynamics; and displaying the result obtained by composing the motions calculated by dynamics and the forces and centers of gravity calculated by inverse dynamics.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2-418249 | 1990-12-25 | ||
| JP2418249A JPH04270372A (en) | 1990-12-25 | 1990-12-25 | Skill developing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2043885A1 true CA2043885A1 (en) | 1992-06-26 |
Family
ID=18526148
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002043885A Abandoned CA2043885A1 (en) | 1990-12-25 | 1991-06-05 | Skill developing method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH04270372A (en) |
| CA (1) | CA2043885A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111260774B (en) * | 2020-01-20 | 2023-06-23 | 北京百度网讯科技有限公司 | Method and device for generating 3D joint point regression model |
-
1990
- 1990-12-25 JP JP2418249A patent/JPH04270372A/en active Pending
-
1991
- 1991-06-05 CA CA002043885A patent/CA2043885A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04270372A (en) | 1992-09-25 |
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Effective date: 19970605 |