Classification of two-degree-of-freedom underactuated mechanical systems

2015 ◽  
Vol 9 (10) ◽  
pp. 1501-1510 ◽  
Author(s):  
Divine Maalouf ◽  
Shunjie Li ◽  
Yannick Aoustin ◽  
Claude H. Moog
Keyword(s):  
Mechanical Systems ◽  
Degree Of Freedom ◽  
Underactuated Mechanical Systems ◽  
Two Degree Of Freedom

Modal Control of Underactuated Systems

2010 ◽  
Author(s):  
D. Dane Quinn ◽  
Vineel Mallela
Keyword(s):  
Control System ◽  
Mechanical System ◽  
Mechanical Systems ◽  
Degree Of Freedom ◽  
Feedback Gain ◽  
Underactuated Systems ◽  
Modal Control ◽  
Underactuated Mechanical Systems ◽  
Sensors And Actuators ◽  
Sensor Actuator

This work addresses the modal control of underactuated mechanical systems, whereby the number of actuators is less than the degree-of-freedom of the underlying mechanical system. The performance of the control system depends on the structure of the feedback gain matrix, that is, the coupling between sensors and actuators. This coupling is often not arbitrary, but the topology of the sensor-actuator network can be a fixed constraint of the control system. This work examines the influence of this structure on the performance of the overlying control system.

Technical Note: A two-degree-of-freedom ambulance stretcher suspension: Part 3: Laboratory and road test performance

1998 ◽  
Vol 212 (5) ◽  
pp. 401-407 ◽  
Author(s):  
R. J. Henderson ◽  
J. K. Raine
Keyword(s):  
Test Performance ◽  
Natural Frequencies ◽  
Low Cost ◽  
Mechanical Systems ◽  
Technical Note ◽  
Suspension System ◽  
Degree Of Freedom ◽  
Road Test ◽  
Pneumatic Suspension ◽  
Two Degree Of Freedom

Parts 1 and 2 of this paper gave a design overview and described the dynamics of a prototype two-degree-of-freedom pneumatic suspension for an ambulance stretcher. This concluding part briefly reviews laboratory shaker table and ambulance road test performance of the suspension with passive pneumatic damping. The suspension system is found to offer compact low-cost isolation with lower natural frequencies than achieved in earlier mechanical systems.

Vibrations of Dynamical Systems With Quadratic Nonlinearities

1965 ◽  
Vol 32 (3) ◽  
pp. 576-582 ◽  
Author(s):  
P. R. Sethna
Keyword(s):  
Dynamical Systems ◽  
Asymptotic Method ◽  
Degree Of Freedom ◽  
System Parameters ◽  
Quadratic Nonlinearities ◽  
The Stability ◽  
Physical Phenomena ◽  
Two Degree Of Freedom

General two-degree-of-freedom dynamical systems with weak quadratic nonlinearities are studied. With the aid of an asymptotic method of analysis a classification of these systems is made and the more interesting subclasses are studied in detail. The study includes an examination of the stability of the solutions. Depending on the values of the system parameters, several different physical phenomena are shown to occur. Among these is the phenomenon of amplitude-modulated motions with modulation periods that are much larger than the periods of the excitation forces.

scholarly journals Stabilization of Energy Level Sets of Underactuated Mechanical Systems Exploiting Impulsive Braking

2021 ◽  
Author(s):  
Nilay Kant ◽  
Ranjan Mukherjee ◽  
Hassan K Khalil
Keyword(s):  
Energy Level ◽  
Level Set ◽  
Control Strategy ◽  
Level Sets ◽  
Impulsive Control ◽  
Mechanical Energy ◽  
Mechanical Systems ◽  
Degree Of Freedom ◽  
Underactuated Systems ◽  
Underactuated Mechanical Systems

Abstract Recent investigations of underactuated systems have demonstrated the benefits of control inputs that are impulsive in nature. Here we consider the problem of stabilization of energy level sets of underactuated systems exploiting impulsive braking. We consider systems with one passive degree-of-freedom (DOF) and the energy level set is a manifold where the active coordinates are fixed and the mechanical energy equals some desired value. A control strategy comprised of continuous inputs and intermittent impulsive braking inputs is presented. The generality of the approach is shown through simulation of a three-DOF Tiptoebot; the feasibility of implementation of impulsive control using standard hardware is demonstrated using a rotary pendulum.

Limitations in the Modal Superposition for Two-Degree-of-Freedom Systems With Impact Non-Linearities

2001 ◽  
Author(s):  
C.-H. Lamarque ◽  
O. Janin
Keyword(s):  
Mechanical Systems ◽  
Rigid Bodies ◽  
Degree Of Freedom ◽  
Modal Superposition ◽  
Usual Procedure ◽  
Two Degree Of Freedom

Abstract The possibility of building a modal superposition formula for two-degree-of-freedom mechanical systems with impacts is investigated in this paper. This formula is obtained by following the usual procedure which consists in defining generalized frequencies, masses and modes. The example of two rigid bodies colliding underlines the efficiency, as well as the limitations, of the method.

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