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1.
A generalized controller based on stability theory of singularly perturbed systems is proposed, to deal with the problem of bounded actuator inputs in robot trajectory tracking control. The saturation function with error-gain matrix is applied in the torque control law, which ensures the upper bound of torque inputs in any given limited range. Through appropriately setting the entries of the error-gain matrix, the tracking performance can be improved. Moreover, a pseudo signal is generated from a linear filter to substitute for the actual velocity error, eliminating the need for velocity measurements. Finally, to verify the effectiveness of the generalized controller, a new saturated controller with error-gain-contained arc tangent function is designed. Comparison experiments show that the proposed controller can strictly guarantee the bound of the torque inputs in situations with non-zero initial tracking errors, and gives a better tracking result than other controllers. 相似文献
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In this paper,a hybrid adaptive compensation control scheme is proposed to compensate the friction occurrence and other nonlinear disturbance factors that exist in the high-precision servo system.An adaptive compensation controller with a dual-observer structure is designed,while the LuGre dynamic friction model with non-uniform parametric uncertainties characterizes the friction torque.Considering the influence of the periodic disturbance torque and parametric uncertainties,fuzzy systems and a robust term are employed.In this way,the whole system can be treated as a simple linear model after being compensated,then the proportional-derivative (PD) control law is applied to enhancing the control performance.On the basis of Lyapunov stability theory,the global stability and the asymptotic convergence of the tracking error are proved.Numerical simulations demonstrate that the proposed scheme has potentials to restrain the impact of disturbance and improving the tracking performance. 相似文献
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Updating parameters according to the driving rate of input,the rate-dependent Prandtl-Ishlinskii(PI)model is widely used in hysteresis modeling and compensation.In order to improve the modeling accurac... 相似文献
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为了研究基于关节力矩信息的笛卡尔阻抗控制策略及摩擦补偿的影响,利用关节本身具有的传感器,进行了辨识谐波驱动摩擦参数、摩擦补偿和笛卡尔阻抗控制的实验研究．与传统的基于机器人末端力／力矩信息的笛卡尔阻抗控制方案不同,考虑了5种基于关节力矩的笛卡尔阻抗控制方案,包括笛卡尔空间／关节空间基于力的、笛卡尔空间／关节空间基于位置的方案和刚度控制．其中,前4种方案分别在有／无摩擦补偿的条件下进行了相应的实验验证．实验比较结果表明：对于基于关节力矩信息来实现笛卡尔阻抗控制的机器人,基于力的阻抗控制策略比基于位置的策略更适合,并且摩擦对这类笛卡尔阻抗控制的稳定性有积极影响． 相似文献
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This paper presents a disturbance rejection scheme for walking robots under unknown external forces and moments. The disturbance rejection strategy, which combines the inverse dynamics control with the acceleration projection onto the ZMP （zero moment point）-plane, can ensure the overall dynamic stability of the robot during tracking the pre-computed trajectories. Under normal conditions, i.e., the system is dynamically balanced, a primary inverse dynamics control is utilized. In the case that the system becomes unbalanced due to external disturbances, the acceleration projection control （APC） loop, will be activated to keep the dynamic stability of the walking robot through modifying the input torques. The preliminary experimental results on a robot leg demonstrate that the proposed method can actually make the robot keep a stable motion under unknown external perturbations. 相似文献
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Dynamic model and control strategy of parallel mechanism have always been a problem in robotics research. In this paper, different dynamics formulation methods are discussed first. A model of redundant driven parallel mechanism with a planar parallel manipulator is then constructed as an example. A nonlinear adaptive control method is introduced. Matrix pseudo-inversion is used to get a desired actuator torque from a desired end-effector coordinate while the feedback torque is directly calculated in the actuator space. This treatment avoids forward kinematics computation that is very difficult in a parallel mechanism. Experiments with PID together with the descibed adaptive control strategy were carried out for a planar parallel mechanism. The results show that the proposed adaptive controller outperforms conventional PID methods in tracking desired input at a high speed. 相似文献
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针对铅电解残阳极板洗涤机中提升装置工作特点及其速度控制系统工作原理,提出了一种基于小脑模型神经网络（CMAC）和PID并行控制策略,前馈控制器以CMAC来实现,并以此完成系统的逆动态模型,系统的稳定性则由PID控制器加以保证,CMAC和PID并行控制器输出完成系统的动作控制.实验结果表明,CMAC-PID控制器具有很高的跟踪能力和抗干扰性,而且响应速度快的多,并且能实现PID参数的在线自适应调整. 相似文献
9.
考虑机器人的不确定项,首先利用反馈控制技术,把基于拉格朗日方程的多关节机器人动力学模型转化成一线性状态方程.然后基于此状态方程,运用变结构控制思想,并结合李雅普诺夫函数设计出一种新的机器人鲁棒控制器,这种控制器能够保证机器人机械臂的跟踪误差渐近收敛到零点.无论是理论推导还是实验仿真都说明了所设计的控制器有着很好的鲁棒性和有效性. 相似文献
10.
Path tracking control of autonomous agricultural mobile robots 总被引：3，自引：0，他引：3
ZHU Zhong-xiang CHEN Jun YOSHIDA Toyofumi TORISU Ryo SONG Zheng-he MAO En-rong 《浙江大学学报(A卷英文版)》2007,8(10):1596-1603
In a tractor automatic navigation system, path planning plays a significant role in improving operation efficiency. This study aims to create a suboptimal reference course for headland turning of a robot tractor and design a path-tracking controller to guide the robot tractor along the reference course. A time-minimum suboptimal control method was used to generate the reference turning course based on the mechanical parameters of the test tractor. A path-tracking controller consisting of both feedforward and feedback component elements was also proposed. The feedforward component was directly determined by the desired steering angle of the current navigation point on the reference course, whereas the feedback component was derived from the designed optimal controller. Computer simulation and field tests were performed to validate the path-tracking performance. Field test results indicated that the robot tractor followed the reference courses precisely on flat meadow, with average and standard lateral devia- tions being 0.031 m and 0.086 m, respectively. However, the tracking error increased while operating on sloping meadow due to the employed vehicle kinematic model. 相似文献
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在人与机器人协调的过程中,控制系统不仅要考虑运动轨迹的位置精度,还要考虑人和机器人与环境接触的灵活性和平滑性。针对柔性多关节机器人动力学前馈的方法进行了研究,使得机器人可以快速、准确地移动到指定位置,控制精度高。提出了一种阻抗控制算法,通过调节机器人末端的阻抗来实现机器人的柔顺控制。依靠动力学的控制策略可以通过调整目标阻抗参数使机器人适应环境。通过对算法的有效性进行仿真验证,该算法可以改善大多数柔性串联机器人的运动控制问题,并且不涉及降低性能以适应操作和控制。 相似文献
13.
张小青 《咸阳师范专科学校学报》2013,(6):21-24
电流滞环跟踪PWM控制技术能较好地得到三相对称正弦波电流,以电流滞环跟踪PWM控制器为内环,转速外环调节器选用PI调节器,建立异步电动机双闭环调速系统.建立系统主电路及控制电路进行仿真模型,主电路由异步电动机模块、电动机测量单元模块、逆变器模块、直流电源、负载模块等组成,控制电路由转速给定信号、转速调节器、电流给定信号及电流滞环跟踪控制器等组成.仿真得到电流、转速及电磁转矩曲线,验证了方法的有效性. 相似文献
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基于拉格朗日函数法建立了机器人的动力模型,并基于滑模控制方法设计了机器人的鲁棒控制器,实现了机器人的平衡、转向和行走等控制任务。滑模控制器是一种鲁棒控制方法,当进入滑模态后,控制能够保证机器人在外力干扰和参数变化等情况下依旧保持控制性能。通过MATLAB和ADAMS联合仿真环境,控制器的控制效果得到了验证,证明了所设计的控制方法是可行的,能够达到所要求的控制性能。 相似文献
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非完整轮式移动机器人运动控制系统的设计与实现 总被引：2，自引：0，他引：2
通过对非完整轮式移动机器人运动学模型的分析，以Elmo HARmonica伺服驱动控制器为核心，设计了轮式移动机器人的运动控制系统。基于Visual C 和OpenGL平台开发了轮式移动机器人轨迹跟踪仿真系统，并进行了轨迹跟踪的仿真试验，取得了满意的控制效果。实验结果表明了运动控制系统设计的有效性。 相似文献
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To improve the machining precision of a surface grinding machine, a micropositioning workpiece table with high performance was used as auxiliary infeed mechanism to implement nanometer level positioning and dynamic compensation. To better understand the characteristics of the grinding machine modulated with micropositioning workpiece table, the dynamic model of the grinding system was established with modal synthesis and Lagrange's equation methods. The grinding system was divided into five subsystems. For each subsystem, the generalized kinematic and potential energies were obtained. Accordingly the dynamic model of the grinding system was given in the modal domain. The waviness of the grinding process was achieved based on the wheel and workpiece vibration. A nonlinear proportional integral derivative (PID) controller with differential trackers was developed to realize dynamic control. The simulation results show that the machining accuracy of the workpiece can be effectively improved by utilizing the micropositioning workpiece table to implement dynamic compensation. An experimental test was carried out to verify the proposed method, and the waviness of the workpiece can be reduced from 0.46 μm to 0.10 μm. 相似文献
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有源电力滤波器（active power filter, APF）补偿电流跟踪控制要求具有较高的稳态精度和较快的动态响应速度。文章将自适应预测滤波算法应用于无差拍控制,实现APF补偿电流精确控制。根据APF时域数学模型,推导滤波系统的无差拍控制离散方程;通过自适应(finite impulse response filter, FIR)预测滤波算法实现基波电流预测,消除控制系统的计算延迟,给无差拍控制提供所需的指令电流预测值。对预测算法进行MATLAB仿真,验证预测算法的稳态精度和动态跟踪快速性;实验室样机验证控制实验结果证明所提出的控制策略有效的,具有一定的实用性。 相似文献
18.
For a single-motor parallel hybrid electric vehicle, during mode transitions （especially the transition from electric drive mode to engine/parallel drive mode, which requires the clutch engagement）, the drivability of the vehicle will be signifi- cantly affected by a clutch torque induced disturbance, driveline oscillations and jerks which can occur without adequate controls. To improve vehicle drivability during mode transitions for a single-motor parallel hybrid electric vehicle, two controllers are proposed. The first controller is the engine-side controller for engine cranking/starting and speed synchronization. The second controller is the motor-side controller for achieving a smooth mode transition with reduced driveline oscillations and jerks under the clutch torque induced disturbance and system uncertainties. The controllers are all composed of a feed-forward control and a robust feedback control. The robust controllers are designed by using the mu synthesis method. In the design process, control- oriented system models that take account of various parameter uncertainties and un-modeled dynamics are used. The results of the simulation demonstrate the effectiveness of the proposed control algorithms. 相似文献
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无标定情况下的视觉定位是机器人视觉伺服领域的热点和难点。提出一种基于快速自适应滤波的机器人无标定手眼协调方法。首先根据机器人三维基坐标建立运动空间和图像特征空间的微分映射关系,在不预先标定视觉传感器与机器人参数情况下,设计一个直接估计增益矩阵 Kk 的自适应滤波器,在线辨识图像雅可比矩阵。采用最小二乘法获得状态估计的初始值,在此基础上设计视觉控制器和计算运动控制量。在 MAT?LAB 环境下建立机器人手眼协调控制系统仿真模型,将该方法用于观测噪声统计特性未知情况下的定位反馈,并对机器人空间螺旋运动的跟踪情况进行分析。实验结果表明,该自适应滤波器能够完成不规则环境下视觉引导的追踪任务,定位效果优于常规卡尔曼滤波和 Sage-Husa 自适应滤波,具有较强的鲁棒性。 相似文献
20.
Implementation of a new PC based controller for a PUMA robot 总被引：1，自引：0，他引：1
FAROOQ M WANG Dao-bo 《浙江大学学报(A卷英文版)》2007,8(12):1962-1970
This paper describes the replacement of a controller for a programmable universal machine for assembly (PUMA) 512 robot with a newly designed PC based (open architecture) controller employing a real-time direct control of six joints. The original structure of the PUMA robot is retained. The hardware of the new controller includes such in-house designed parts as pulse width modulation (PWM) amplifiers, digital and analog controllers, I/O cards, signal conditioner cards, and 16-bit A/D and D/A boards. An Intel Pentium IV industrial computer is used as the central controller. The control software is implemented using VC programming language. The trajectory tracking performance of all six joints is tested at varying velocities. Experimental results show that it is feasible to implement the suggested open architecture platform for PUMA 500 series robots through the software routines running on a PC. By assembling controller from off-the-shell hardware and software components, the benefits of reduced and improved robustness have been realized. 相似文献