Real-time state estimation for spatial six-degree-of-freedom linearly actuated parallel robots

PD control with gravity compensation for hydraulic 6-DOF parallel manipulator

“…The spatial states of parallel manipulator are critical to determine the control input for compensating system gravity, turbulence for the control system of hydraulic 6-DOF parallel manipulator. Fortunately, the real-time forward kinematics for estimating system states has been investigated and implemented with high accuracy (less than 10 À7 m) and sample 1-2 ms [29]. It is should be noted that the steady state error in principle of control system mainly results from system gravity of the 6-DOF parallel manipulator especially for hydraulic parallel manipulator with heavy payload, even though the friction always exists in the system under position control, since the gravity of the payload and upper platform is much more than friction.…”

Computed force and velocity control for spatial multi-DOF electro-hydraulic parallel manipulator

“…The kinematics and dynamics of spatial parallel industrial robot have been investigated extensively [15,16]. Hence, the dynamic equation of mechanical system is briefly described for multi-DOF parallel manipulator, which is described by a second-order nonlinear differential equation.…”

“…., q 6 ) of the moving platform by using analytical method, while the latter is used to calculate the generalized pose with a set of measured actuator length via global Newton-Raphson with monotonic descent algorithms which is formulated by (3). The details of real time forward kinematics using global Newton-Raphson with monotonic descent algorithms and inverse kinematics based on analytical method can be referred in [15].…”

Dynamic modeling and computational efficiency analysis for a spatial 6-DOF parallel motion system

“…The linear motions are denoted as surge (q 1 ), sway (q 2 ), and heave (q 3 ) along the X L -Y L -Z L axis for base coordinate system, and the angular motions la- The dynamics and kinematics of 6-DOF parallel motion system have been investigated extensively [22][23][24][25]. Several methods, such as Lagrange equation, Netwon-Euler and Kane methods, principle of virtual work, are presented to derive dynamic equation of the spatial 6-DOF parallel manipulator.…”