WP1 Analysis and Modeling of Legged Locomotion
Action 1-1: Study of human and animal movement (UTH). Humans and animals will be guided onto a 15m flat long track instrumented with two force plates in view of motion analysis cameras and at least 5 valid gait cycles (different speeds) for each subject will be collected. Validity of trials will be checked between trials, allowing rest. Limb and body kinematics will be recorded using our 10-camera Vicon motion analysis system. Multiple markers will be positioned on each segment to obtain realistic 3D motions. The lab already has one platform but one more must be purchased and linked with the existing one. This will optimize successful individual limb force measurements during gait. The plates will be topped with rubber matting to prevent slipping. The flat track is measured as a reference for subsequent experimental conditions. Potential energy gain in different gaits will be calculated from force plate data where possible, or where not by markers on the torso (approximating CoM location).
Action 1-2: Modelling of quadruped robots (NTUA). A detailed model of a quadruped robot, required in the control studies, will be developed. This model will include all degrees of freedom available in the prototype robot and will be parametric. This way, the robot parameters (dimensions, leg length, joint stiffness, DOFs, actuators, weight, etc.) can be changed to investigate how performance and stability change accordingly. The model will have at least 4 DOFs on each leg (two on the hip, one on the “elbow” joint, and one prismatic at the lower leg part). These can be either active or passive. Furthermore, one or two DOFs will be added to the robot’s main body, which will emulate the spinal movement in animals. The model of the quadruped will be done in Matlab, which will allow the application of different control strategies and algorithms in the future. Another option, which has also been used in the past, is to develop the physical model in ADAMS environment, which is then connected to Matlab so that the control algorithm can be applied to the model.
Action 1-3: Modelling of multi-legged robots (FORTH). Analytical and computational models of elongated, segmented, multi-legged robots and their pedundulatory locomotion on planar and non- planar solid and granular environments will be developed. These models will be based on existing modelling and simulation tools, which will be expanded to model joint and appendage flexibility, and simulate movement over uneven terrains. Computational models describing the acquisition of sensory information and means for neuromuscular control (e.g., models of muscles and networks of neural oscillators) will also be incorporated. Computational tools supporting morphological changes and optimization studies (e.g., by genetic algorithms) may be incorporated. The models will be validated in WP3 and WP4 by appropriate robots and experiments, and, if needed, they will be refined or updated.
Action 1-4: Modelling of biped robots (FORTH). Computational models of humanoid robots will be developed, to support studies of bipedal locomotion. Modelling of the anatomical characteristics of the human body, primarily those relating to locomotion (rather than grasping or object manipulation) will be emphasized. Models specific to available experimental prototypes may also be developed, if necessary, which will be validated appropriately.