Static optimal estimation of joint accelerations for inverse dynamics problem solution

2002 ◽  
Vol 35 (11) ◽  
pp. 1507-1513 ◽  
Author(s):  
Violaine Cahouët ◽  
Martin Luc ◽  
Amarantini David
1990 ◽  
Vol 6 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Maury L. Hull ◽  
Hiroko K. Gonzalez

Using a five-bar linkage model of the leg/bicycle system in conjunction with experimental kinematic and pedal force data, the inverse dynamics problem is solved to yield the intersegmental moments. Among the input data that affect the problem solution is the height of the pedal platform. This variable is isolated and its effects on the total joint moments are studied as it assumes values over a ±4-cm range. Platform height variation affects the total joint moment peak values by up to 13%. Relying on a cost function derived from the hip and knee moments, it is found that the platform height that minimizes the cost function is +2 cm. The sensitivity of the cost function to the platform height variable is low; over the variable range the cost function increases 2% above the minimum. These results hold for a pedaling rate of 90 rpm. As pedaling rate is varied above and below 90 rpm, the sensitivity of the cost function increases. The platform heights that minimize the cost function are the lower and upper limits for 60 and 120 rpm, respectively. Thus the platform height variable interacts with pedaling rate, requiring a compromise in platform height adjustment. The compromise height depends on the individual’s preferred pedaling rate range.


Author(s):  
Krzysztof Tchoń ◽  
Katarzyna Zadarnowska

AbstractWe examine applicability of normal forms of non-holonomic robotic systems to the problem of motion planning. A case study is analyzed of a planar, free-floating space robot consisting of a mobile base equipped with an on-board manipulator. It is assumed that during the robot’s motion its conserved angular momentum is zero. The motion planning problem is first solved at velocity level, and then torques at the joints are found as a solution of an inverse dynamics problem. A novelty of this paper lies in using the chained normal form of the robot’s dynamics and corresponding feedback transformations for motion planning at the velocity level. Two basic cases are studied, depending on the position of mounting point of the on-board manipulator. Comprehensive computational results are presented, and compared with the results provided by the Endogenous Configuration Space Approach. Advantages and limitations of applying normal forms for robot motion planning are discussed.


Author(s):  
Shaoqian Wang ◽  
Amir H. Ghasemi ◽  
Joshua L. Evans ◽  
T. Michael Seigler

This paper addresses the problem of controlling a rigid body’s orientation by actuating sinusoidal oscillations of internal momentum wheels. We consider the rotational dynamics of a rigid body having three momentum wheels (one for each body-fixed axis) that are attached to the body by springs. Each wheel is actuated by an internal sinusoidal torque of fixed frequency. The frequency of all sinusoidal torques is equal, but the amplitudes and phases can be varied independently. We analyze the inverse-dynamics problem of determining the amplitudes and phases for each sinusoidal torque such that a desired orientation is achieved. We then present two closed-loop orientation controllers based on this analysis. Numerical simulations demonstrate the effectiveness of the control techniques.


2020 ◽  
Vol 7 (3) ◽  
pp. 465-475
Author(s):  
Abdallah M. Elsherbiny ◽  
Amgad M. Bayoumy ◽  
Ahmed M. Elshabka ◽  
Mohamed M. Abdelrahman

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