Animation of Human Gait

TitleAnimation of Human Gait
Publication TypeBook Chapter
Year of Publication1991
AuthorsBruderlin A, Calvert TW
EditorPatla AE
Book TitleAdaptability of Human Gait - Implications for the Control of Locomotion
Series TitleAdvances in Psychology
Pagination305 - 330

Recent developments in computer animation have made available more advanced methods to visualize human movements. These find application in entertainment, education, scientific visualization, ergonomic evaluation and as a medium for artistic expression. Two of the principal objectives which need to be addressed if human figure animation is to become more practical are the convenient, high level specification of movement sequences and the production of truly realistic movement. In order to provide convenient means of specifying movements there has been a tendency away from cell animation, where the user defines key positions in time, toward higher levels of control, where movements are specified as tasks like "walk to the door". The computer "knows" about these tasks, decomposes them and calculates the proper joint angles over time. To attain a greater degree of motion realism techniques from robotics and biomechanics are being applied, where movements are generated through forces acting on masses of bodies. This paper introduces a method to animate human locomotion based on these principles. A generic locomotion cycle is derived from a simple dynamic model. The forces and torques which control this model are internally generated from knowledge about human gait. The mechanical and robot-like appearance of the simulated motion is visually enhanced and humanized through kinematic algorithms; a human leg is superimposed onto the simplified dynamic pendulum leg, a pelvis is induced and the arm swing and shoulder rotation during locomotion are expressed as functions of the lower body movements. The system which has been implemented can produce quite realistic looking human walks under a fairly wide range of conditions upon specification of only a few parameters, such as desired walking speed and step length. This will be extended in a straightforward way to running and locomotion over uneven terrain, up and down stairs, etc. Studies are also underway to determine how this approach can be applied to non-locomotory movement.