摘要:
A medical robotic system has a joint coupled to medical device or a slave manipulator or robotic arm adapted to hold and/or move the medical device for performing a medical procedure, and a control system for controlling movement of the joint according to user manipulation of a master manipulator. The control system includes at least one joint controller having a sliding mode control for reducing stick-slip behavior on its controlled joint during fine motions of the joint. The sliding mode control computes a distance to a sliding surface, computes a reaching law gain, and processes the distance and reaching law gain to generate a sliding mode control action that is in absolute value less that a maximum desired feedback control action. The sliding mode control action is then further processed to generate a feedback torque command for the joint motor.
摘要:
A low cost control apparatus of a contact mechanism resolving a disadvantage caused when a contact body is moved to make contact with a contacted body by an actuator. A synchronizing mechanism, which a coupling sleeve rotatably and integrally provided with an input shaft is pushed against a synchronizer ring disposed between the coupling sleeve and a synchronized gear, thereby synchronizing rotational speeds of both the components to engage them, is modeled as a collision between an inertia system object and an elastic system object. A computation coefficient (VPOLE, f in FIG. 9) of a switching function for sliding mode control having a deviation between an actual position of the coupling sleeve (Psc, d in FIG. 9) and a target position (Psc_cmd, e in FIG. 9) as a state variable is changed depending on the actual position (Psc), and thereby changing a control ability of the model against a disturbance.
摘要:
The present invention provides an adaptive sliding mode control method capable of not only improving the convergence of estimated parameters but also providing outstanding vibration-damping properties. In this method, a position deviation .epsilon. between a command position and a motor position, a speed deviation .epsilon., and a position command acceleration .theta.r are determined. The difference .epsilon.t between the motor position and the position of machine's moving part and a differential .epsilon.t based thereon are obtained by observer processing and filtering processing. A phase plane Suf of the motor is obtained by feeding back the deviation .epsilon.t between the motor position and the position of the machine's moving part. Estimated values Jhat, Ahat and Grhat, representing an inertia term, coefficient of dynamic friction, and gravity term respectively, are obtained. A switching input .tau.1 is set to the maximum Dis or minimum Dis of a disturbance depending on the plus/minus sign of the phase plane Suf. A torque command .tau. for the motor is obtained and delivered to a current loop. With this method, the vibration of the machines moving part after positioning can be reduced.
摘要:
A control input for controlling a driving force of an actuator (5), by a control processing of the sliding-mode control using a switching function configured from a first variable component, which is a deviation between an observed value of a secondary power imparted to a secondary element (3) from a primary element (2) via an elastic deformation member (4), and a second variable component which is a temporal change rate of the deviation, so as to converge the first variable component to zero on the switching hyperplane. A gradient of the switching hyperplane is preliminarily determined based on a response characteristics data satisfying a predetermined requirement.
摘要:
A medical robotic system has a joint coupled to medical device or a slave manipulator or robotic arm adapted to hold and/or move the medical device for performing a medical procedure, and a control system for controlling movement of the joint according to user manipulation of a master manipulator. The control system includes at least one joint controller having a sliding mode control for reducing stick-slip behavior on its controlled joint during fine motions of the joint. The sliding mode control computes a distance to a sliding surface, computes a reaching law gain, and processes the distance and reaching law gain to generate a sliding mode control action that is in absolute value less that a maximum desired feedback control action. The sliding mode control action is then further processed to generate a feedback torque command for the joint motor.
摘要:
A position control device for causing a position of a control system, including a servomotor and a moving body driven by the servomotor, to track a command value. The position control device includes a sliding mode controller for receiving command position r and state variable x of the control system and for providing a control input u to the servomotor. State variable x is expressed as follows: x = [ θ θ . ] , where θ is feedback position and {dot over (θ)} is feedback velocity. The position control device also includes a disturbance variable compensator for compensating control input u based on feedback velocity {dot over (θ)}.
摘要:
A low cost control apparatus of a contact mechanism resolving a disadvantage caused when a contact body is moved to make contact with a contacted body by an actuator. A synchronizing mechanism, which a coupling sleeve rotatably and integrally provided with an input shaft is pushed against a synchronizer ring disposed between the coupling sleeve and a synchronized gear, thereby synchronizing rotational speeds of both the components to engage them, is modeled as a collision between an inertia system object and an elastic system object. A computation coefficient (VPOLE, f in FIG. 9) of a switching function for sliding mode control having a deviation between an actual position of the coupling sleeve (Psc, d in FIG. 9) and a target position (Psc_cmd, e in FIG. 9) as a state variable is changed depending on the actual position (Psc), and thereby changing a control ability of the model against a disturbance.
摘要:
A sliding mode control method is provided capable of improving the following ability of a control system with respect to a command at the time of change in the operating condition of a machine, and preventing vibration which tends to occur by the action of a spring element of the machine at the time of change in the operating condition. The processor of a servo circuit derives position deviation (.epsilon.) and speed deviation (.epsilon.) based on a command position (.theta.r) and an actual position (.theta.), estimates an torsion amount (.epsilon.n) and torsion speed (.epsilon.n) by effecting observer processing (Steps 100 to 101), and derives a switching variable (s) (102). The processor derives each of the first to fourth terms of the switching input in dependence on the positive or negative sign of the switching variable, and the positive or negative sign of a corresponding one of the position deviation, the second derivative of the command position, the torsion amount, and the torsion speed (103 to 129), and then derives, on the basis of the switching input derived by adding the four terms together, a torque command (T) sufficient to cause the switching variable to converge on 0 (130, 131). The servo system properly follows the command even when nonlinear parameters associated with the spring element of the machine have varied, thereby preventing vibration of the machine.
摘要:
A robotic surgical system includes an arm, a tool, an input controller, and a processing unit. The arm includes an end that supports the tool which is moveable an output distance within a surgical site. The input controller is movable an input distance at an input velocity and acceleration. The processing unit is in communication with the input controller and is operatively associated with the arm to move the tool the output distance. The processing unit is configured to dynamically scale the output distance in response to the input distance, velocity, and/or acceleration.