共查询到20条相似文献，搜索用时 0 毫秒
1.
《Mechatronics》2021
Robotic manipulation of objects using the sole tactile feedback is a challenge. If the contact between the robot end effector and the manipulated object is distributed, the robot can exchange both friction forces and torques with it. The friction highly influences the motion of the object. By controlling the friction it is possible to perform complex manipulation tasks, such as moving the object with respect to the end effector by executing a controlled sliding motion. If the motion is a rotation with respect to the end effector, the corresponding maneuver is called pivoting. Control of the pivoting motion is considerably difficult, especially without any visual feedback. This paper proposes a novel method to regulate the object angular position, by means of a pivoting maneuver, through a parallel gripper endowed with force/tactile sensors. The strategy is based on a novel nonlinear observer that estimates the sliding velocity from force/torque measurements and a model of the sliding dynamics. We exploit the Limit Surface concept and the LuGre friction model to build a dynamic model of a planar slider. We show, through experimental results, that simple parallel grippers are able to execute such maneuvers that correspond to adding a virtual joint between the fingers, thus enlarging the robot workspace. 相似文献
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《Mechatronics》2014,24(8):1242-1253
This paper deals with the control system design of active seat suspension. The proposed control system structure is built basing on several various controllers. The primary controller is used to evaluate the actual value of the desired active force that should be generated in the suspension system. The secondary controller is employed to calculate the instantaneous value of a signal which controls the active element by means of its reverse model. The adaptation mechanism recognises the actual suspended mass in order to increase the effectiveness of vibration isolation. Additionally, the system robustness for different load masses is investigated using computer simulation and experimental research. 相似文献
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《Mechatronics》2015
The KAI manipulator is a four joint mobile manipulator, which will be used within the German road clearance package to investigate improvised explosive devices and ordnance from within an armored vehicle. To improve handling of the manipulator, a Tool-Center-Point (TCP) control is implemented. By using constrained quadratic optimization (cQP) it is possible to allow for the control of the manipulator within three different operating spaces. The QP is formulated to account for constraints in the joint angular rates and TCP velocities, as well as additional velocity constraints, e.g. on the movement of the center of mass of the manipulator. The proposed algorithm is able to handle redundant as well as non redundant manipulator kinematics. By using an efficient QP solver the algorithm can be used within a real-time trajectory generation scheme. The performance of the algorithm is demonstrated using simulation results and validated by measurements of the TCP control. 相似文献
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在快速变化的干扰环境下,无线通信系统传输可靠性会受到很大影响。为提升快速时变干扰环境下无线通信系统传输的可靠性,该文提出一种基于干扰观测的无线通信系统抗干扰功率控制算法。该算法首先将受到干扰影响的无线通信系统建模为广义稳定性控制系统,并采用干扰观测器生成系统状态受干扰影响的估计值。然后通过利用估计值来预测未来的跟踪误差和稳态的控制输入,优化系统的控制策略以实现对干扰环境的自适应调整。最后仿真结果表明,与传统方法相比,所提算法能够快速响应干扰变化,显著提高系统在快速时变恶意干扰下传输的可靠性,提高了系统对干扰环境的适应能力。 相似文献
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《Mechatronics》2015
Ultrasonic actuators used in high-precision mechatronics possess strong frictional effects, which are among the main problems in precision motion control. Traditional methods apply model-based nonlinear feedforward to compensate the friction, thus requiring closed loop stability and safety constraint considerations. In this article, model-based parametric controllers are developed to obtain an optimal positioning control for these motors. A systematic approach which uses piecewise affine models greatly simplifies the friction model compared to the traditional methods. Issues about the nonlinear effects of the friction are addressed by designing a robust control law near zero speed. These developments result in a gain-scheduling optimal input, which is simple to carry out in real-time applications. The controller is expected to improve the safety constraints and the tracking performance for actuator operation. 相似文献
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Francesco Basile Fabrizio Caccavale Pasquale Chiacchio Jolanda Coppola Alessandro Marino 《Mechatronics》2013,23(8):1100-1112
In this paper a two-layer decentralized framework for kinematic control of cooperative and collaborative multi-robot systems is developed. The motion of the system is specified at the workpiece level, by adopting a task-oriented formulation for cooperative tasks. The first layer computes the motion of the single arms in the system. In detail, the control unit of each robot computes the end-effector motion references in a decentralized fashion on the basis of the knowledge of the assigned cooperative task and the motion references computed by its neighbors. Then, in the second layer, each control unit computes the reference joint motion of the corresponding manipulator from the end-effector reference motion. The approach is, then, tested in simulation on a work-cell composed by several manipulators, and experimentally on a dual-arm kinematically redundant work-cell composed by industrial manipulators. 相似文献
7.
The trajectory planning of redundant robots through the pseudoinverse control leads to undesirable drift in the joint space. This paper presents a new technique to solve the inverse kinematics problem of redundant manipulators, which uses a fractional differential of order α to control the joint positions. Two performance measures are defined to examine the strength and weakness of the proposed method. The positional error index measures the precision of the manipulator's end-effector at the target position. The repeatability performance index is adopted to evaluate if the joint positions are repetitive when the manipulator execute repetitive trajectories in the operational workspace. Redundant and hyper-redundant planar manipulators reveal that it is possible to choose in a large range of possible values of α in order to get repetitive trajectories in the joint space. 相似文献
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《Mechatronics》2014,24(5):407-415
Hysteresis torsion in elastic robot joints occurs as a coupled nonlinearity due to internal friction, backlash, and nonlinear stiffness, which are coactive inside of mechanical transmission assemblies. The nonlinear joint torsion leads to hysteresis lost motion and can provoke control errors in relation to the joint output at both trajectories tracking and positioning. In this paper, a novel modeling approach for describing the nonlinear input–output behavior of elastic robot joints is proposed together with the observation and control method, which aim to compensate for the relative joint torsion without load sensing. The proposed modeling approach includes the recently developed 2SEP dynamic friction model and Bouc–Wen-like hysteresis model, which is originated from structural mechanics, both arranged according to the assumed torque transmitting structure. The proposed method is evaluated with experiments using the laboratory setup which emulates a single rotary joint under impact of nonlinear elasticities, friction, and gravity. 相似文献
9.
从数学上建立了预测控制与PID控制的广义联系,并结合某火电厂300MW锅炉机组,针对烟气氧含量控制回路,在不改变原有控制系统框架的基础上,采用基于GPC的PID控制方法,很好地解决了在锅炉负荷和氧含量设定值同时变化的情况下系统的动态响应不理想的问题。通过MATLAB仿真,验证了该控制系统具有较好的控制品质,适合具有一定延迟的复杂控制系统。 相似文献
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《Mechatronics》2021
Permanent magnet synchronous motors are widely used in elevator applications. This is due to their high efficiency and reliability, whereby motors are directly connected to the elevator ropes without the need of having a gearbox. This efficient system comes with some new challenges regarding the control of the motor. Since no gearbox is added to the system, the motor speed oscillations are directly transferred to the elevator cabin. This urges the need of having a smooth control algorithm to suppress the measurement noises generated by the absolute encoder especially at low speed. On the other hand, whenever the mechanical brakes are released, the speed controller needs to react quickly to prevent the cabin from rolling back. In order to overcome these challenges, this paper presents an improved speed control algorithm that reacts quickly in transient state to reduce the rollback of the cabin and slowly at steady state to ensure smooth ride. The proposed controller is based on the combination of a Model Predictive Controller (MPC) along with a torque observer. It also benefits from being computationally less demanding unlike other MPC techniques. The proposed controller is experimentally tested on an elevator and then compared to classic controllers. Finally, conclusions are drawn. 相似文献
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由于传统直接转矩控制采用滞环控制器,因此不可避免导致较大转矩脉动,本文使用基于评估函数的永磁同步电机模型预测直接转矩控制,对转矩环使用预测算法代替滞环控制。首先建立模型预测控制系统模型,阐述具体实施流程并优化预测算法,最后:与直接转矩控制进行仿真比较,结果表明,所提出的优化模型预测直接转矩控制相较于传统直接转矩控制,更... 相似文献
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《Mechatronics》2022
This work investigates the coordinated motion control and obstacle-crossing problem for a four wheel-leg independent motor-driven robotic system via a model predictive control (MPC) approach based on an event-triggering mechanism. The modeling of a wheel-leg robotic control system with a dynamic supporting polygon is organized. The system dynamic model is 3 degrees of freedom ignoring the pitch, roll, and vertical motions. The single wheel dynamic is analyzed considering the characteristics of the motor-driven and the Burckhardt nonlinear tire model. As a result, an over-actuated predictive model is proposed with the motor torques as inputs and the system states as outputs. As the supporting polygon is only adjusted at certain conditions, an event-based triggering mechanism is designed to save hardware resources and energy. The MPC controller is evaluated on a virtual prototype as well as a physical prototype. The simulation results guide the parameter tuning for the controller implementation in the physical prototype. The experimental results on these two prototypes verify the efficiency of the proposed approach. 相似文献
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预测函数控制（PFC）是一种新颖的预测控制算法。本文应用PFC算法实现对一阶过程的控制。仿真结果表明,该算法具有较强的鲁棒性和抑制干扰能力。 相似文献
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《Mechatronics》2021
Reactive multi-robot manipulation can be of great assistance in many applications. In this article a distributed cooperation strategy for object manipulation with multiple robots in un-modelled environments is proposed to tackle workpiece transportation and dynamic obstacle avoidance simultaneously. A decentralised optimisation process will run first to generate robot pose references and then a joint-level control is responsible for tracking. Since in multi-arm manipulation systems the available workspace for each robot is more restricted, necessary internal performance optimisation is also included in the planning phase. A velocity-level optimum will be solved and then transformed to a position-level control reference so that it can be combined with many compliant interactive controllers such as impedance control. Although no torque or force sensor is required and each robot only has access to local information, when avoiding obstacles the coordination strategy can generate synchronised group motion so that internal forces are avoided. Only task-space variables will be communicated, therefore it is easy to team up different types of robots, making the system more flexible. Simulation and experiments with two redundant manipulators have been done to validate the proposed design, and data show that the online computation speed is fast. 相似文献
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In this paper we present a novel algorithm to model predictive contouring control for biaxial feed drive systems. model predictive control (MPC) refers to a class of model-based controllers that uses an explicit process model and tracking error dynamics to predict the future behavior of a plant, making it effective for machine tool feed drive systems that must achieve high-precision motion and are severely affected by friction, cutting force and changes in the workpiece mass. To improve contouring performance, we propose a new performance index in which error components orthogonal to the desired contour curve are given more importance than tracking errors with respect to each feed drive axis. Controller parameters are calculated in real time by solving an optimization problem. The parameters depend on the instantaneous slope of the reference trajectory and thus vary with time for curved reference trajectories, resulting in a time-varying controller. Weighting factors for the error components in orthogonal and tangential directions are used to adjust the error importance in each direction. In addition, to consider the required feed drive energy, the control inputs in both directions are included in the performance index. The effectiveness of the proposed control approach is demonstrated with an experimental biaxial feed drive system for circular and non-circular trajectories. The proposed contouring controller allows the feed drive to follow smooth curves and reduces contouring error. 相似文献