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Summary In this paper, the tracking control problem for a class of nonlinear time‐delay multiagent systems with input saturation is considered. The nonlinear dynamics are dominated by strict‐feedback form and satisfy Lipschitz conditions with constant gains. First, it indicated that the tracking control problem is equivalent to a general bound problem of high‐dimensional multivariable systems. Second, an ingenious state transformation is utilized to change the bound problem into the parameter design problem. Third, by the static gain control technique and the hyperbolic tangent function, both state feedback and output feedback controllers are built such that all signals of the closed‐loop systems are globally bounded, and the tracking errors between the followers and the leader can converge to a small neighborhood around the origin by appropriately selecting parameters. Finally, an example is shown to verify the feasibility of our results.

Passive compliance plays an important role in robot pick-and-place manipulation where large interaction force will be produced in response to small misalignments. In this paper, the authors report on compliance analysis and validation of a novel planar pick-and-place parallel manipulator consisting of a flexible limb. In the proposed manipulator, a planar flexible parallelogram linkage, which is coupled with a rigid one, is introduced to connect the moving and the base platforms. Since the flexible parallelogram linkage is capable of producing large deformation in both the horizontal and the vertical directions, the end effector of the manipulator can generate wide-range motions because of the flexible links. An efficient approach to the large deflection problem of flexible links is used to precisely predict the kinetostatics of the manipulator. Then, a compensation algorithm to the structural deflection of the links can be developed to actively control the position of the parallel manipulator’s end effector. The merit of the proposed flexible manipulator is its intrinsic passive compliance while performing pick-and-place tasks. A prototype is fabricated to conduct experiments for the validation of the proposed idea. The results show that the prototype has acceptable positioning accuracy, even when a large external load is exerted on its end effector. The compliance properties of the proposed flexible manipulator have also been verified in both the horizontal and the vertical directions.

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This article proposes a new reconfigurable parallel mechanism using a spatial overconstrained platform. This proposed mechanism can be used as a machine tool. The mobility is analyzed by Screw Theory. The inverse kinematic model is established by applying the closed-loop equation. Next, the dynamic model of the presented mechanism is established by Lagrange formulation. To control the presented mechanism, some controllers have been used. Based on this dynamic model, the fuzzy-proportion integration differentiation (PID) controller is designed to track the trajectory of the end effector. For each limb, a sliding mode controller is applied to track the position and velocity of the slider. Finally, some simulations using ADAMS and MATLAB are proposed to verify the effectiveness and stability of these controllers.