This article extends to three-dimensional tasks the method of camera space manipulation. A minimum of two cameras is required to place points on end effectors (or objects in their grasp) of n-degree-of-freedom manipulators relative to other bodies. This is accomplished using a sequential estimation scheme that permits placement of these points in each of the two-dimensional image planes of monitoring cameras. A precise and robust manipulation strategy that is compatible with "real time" results. Simulations are used that show the method to be insensitive to two particular kinds of model error- unmodeled elastic deflection and unmodeled camera distortion. The method is tested experimentally with a three- dimensional point placement task. It is then generalized to rigid body placement tasks and illustrated with experiments involving the positioning of one rigid body on a second. An appendix details the unfolding of one such experimental maneuver at several junctures in the visual data-collecting process.
This study discusses a non-contact optical technique(electronic speckle pattern interferometry) that is well suited for thermal deformation measurement without any surface preparation and compensating process. Fiber reinforced plastics ([0] 16, [0/90J8S) were analyzed by ESPI to determine their thermal expansion coefficients. The thermal expansion coefficient of the transverse direction of a uniaxial composite is evaluated as 48.78 X 10-6 (1/'C ). Also, the thermal expansion coefficient of the cross-ply laminate [0/90J85 is numerically estimated as 3.23 X 10-6 (l/'C) that is compared with that measured by ESPI.
A negative input shaped command is presented for flexible systems to reduce the residual oscillation under unequal acceleration and braking delays of actuators that are common issues in industrial applications. Against this nonlinearity, a compensated unit magnitude zero vibration (UMZV) shaper is analytically developed with a phasor vector diagram and a ramp-step function to approximate the dynamic response of the unequal acceleration and braking delays of actuators. A closed-form solution is presented with a benchmark system without sacrificing the generality and simplicity for industrial applications. The robustness and control performance of the exact solution are numerically evaluated and compared with those of an existing negative input shaper in terms of the switch-on time, command interference, and effects of the shaper parameters. The proposed negative input shaped commands are experimentally validated with a mini-bridge crane.
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