In this paper, we introduce cascade normal forms for underactuated mechanical systems that are convenient for control design. These normal forms are partially linear which results from a well-known fact that underactuated systems can be partially linearized using a change of control [12]. The difficulty arises when the new control appears both in the linear and nonlinear subsystems. We introduc...

ivThe class of underactuated systems is composed of a variety of mechanical as well asbiological systems. The term underactuation refers to the fact that not all joints or degrees-of-freedom (DOFs) of the system are equipped with actuators, or are directly controllable.The DOFs of an underactuated system are dynamically coupled, and their dynamicequations are nonlinear and a...

We introduce the notion of kinematic controllability for second-order underactuated mechanical systems. For systems satisfying this property, the problem of planning fast collision-free trajectories between zero velocity states can be decoupled into the computationally simpler problems of path planning for a kinematic system followed by timeoptimal time scaling. While this approach is well know...

In this paper, we address nonlinear control and reduction of a class of high-order underactuated mechanical systems with kinetic symmetry called Class-I systems. Class-I systems are underactuated systems with actuated shape variables, decoupled inputs, and integrable normalized momentums (all to be de ned). We show that all Class-I underactuated systems can be transformed into cascade systems i...

In this report, different control techniques for underactuated systems are considered. Underactuated systems are systems that have more degrees of freedom to be controlled than independent control inputs. Several control-techniques are considered for the point-to-point control of underactuated mechanical systems. After that, a control technique is considered for tracking control of underactuate...

The authors consider the control of an underactuated mechanical system: Pendubot, which has four separated equilibrium points. A unified controller is proposed to stabilise the system at the four equilibrium points. Moreover, the proposed unified control can bring the underactuated link to ideal homoclinic orbits, which cannot be achieved by existing approaches. Simulation results verify the ef...

Abstract—The dynamic control of a 3R underactuated robot is investigated in this paper. The second order nonholonomic dynamic equation of the robot is derived. An intelligent control method is proposed for the position control of underactuated manipulator based on genetic algorithm. A new fuzzy controller for motion control of underactuated robot is presented, in which the joint angular errors ...

A new concept for controlling of underactuated robot manipulators is presented by using switching computed torque method. One fundamental feature of the present approach is to use the partly stable controllers (PSCs) in order to fulfill the ultimate control objective. Dynamic model of an underactuated robot system is directly analyzed to synthesize partly stable, computed torque controllers wit...

In this report, different control techniques for underactuated systems are considered. Underactuated systems are systems that have more degrees of freedom to be controlled than independent control inputs. Several control-techniques are considered for the point-to-point control of underactuated mechanical systems. After that, a control technique is considered for tracking control of underactuate...

Underactuated manipulators are robot manipulators composed of both active and passive joints in serial chain mechanisms. The study of underactuation is significant for the control of a variety of rigid-body systems, such as free-floating robots in space and gymnasts, whose structure include passive joints. For mechanisms with large degrees of freedom, such as hyper-redundant snake-like robots a...