Biomechanics and Robotics - Simulating terrestrial walking
As a part of my Biomechanics and Robotics course I had to build two simulations for terrestrial walking. The first simulation was for terrestrial walking on a planar surface and the second simulation for walking up a flight of steps.
The assumptions made while simplifying the problem were -
1.) The mass of the upper body is located at the hip joint.
2.) The mass of the legs is neglected.
The step length was 1.5m and the maximum speed of 3m/s.
Terrestrial Walking on Planar surface
I adopted two approaches two find solution to this problem. In the first approach the Center of Mass(COM) moves from starting point to 0.75m in single support phase on right leg and then moves from 0.75m the COM moves on single support phase on left leg. The robot meets the condition of ZMP being at the point of contact all the time.
In the second approach the COM moves from starting point to (0.75/2)m in single support phase on right leg. Then from 0.75/2 to (0.75/2+0.75/4)m in double support phase, and then from (0.75/2+0.75/4)m to the end point in single support phase on left leg. The robot meets the condition of ZMP being at the point of contact during single support phase and between the two support points during double support phase.
Project Code for Attempt 1 can be found here.
Project Code for Attempt 2 can be found here.
Terrestrial Walking Up a Flight of Steps
According to analysis of human gait ( https://www.youtube.com/watch?v=FRdK2kO80A8 ) while walking upstairs we can see that the COM moves forwards and above the point of contact of the forward foot and then the forward foot raises the COM upwards while bringing the trailing foot forward. The ZMP conditions are met while moving the left food forwards. The right leg provides the necessary force. Once the left foot touches the ground, the right leg leaves contact with the ground and the COM rises above.