基于摆角约束的双摆吊车轨迹规划

桥式吊车作为一种典型的欠驱动系统,已经在现代工业生产运输过程中得到了广泛的应用。但当吊车系统中的负载体积过大或吊钩质量较大时,桥式吊车系统会呈现双摆特性,增加控制难度。针对这一问题,提出了一种基于摆角约束的双摆桥式吊车轨迹规划策略,以更方便地考虑摆角约束。首先,设计能够满足摆角约束的摆角运动曲线,并由台车运动与两级摆角之间的耦合关系得出台车加速度轨迹;然后,构造关于时间和最大摆角的目标函数;最后,将轨迹规划问题转化成一个可利用粒子群算法来求解的优化问题。MATLAB仿真对比结果表明,该方法在实现台车快速精准定位的同时,能有效抑制两级摆动及残余摆动,在系统参数改变时仍具有较好的鲁棒性,可尝试应用于实际工作中。     

基于伪谱法的双摆吊车时间最优消摆轨迹规划策略

在工业生产过程中,桥式吊车系统经常会体现出双摆系统的特性,导致更多欠驱动状态量的出现,增大控制难度.基于此,论文提出了一种针对双摆桥式吊车系统的时间最优轨迹规划方法,可以得到全局时间最优且具有消摆能力的轨迹.具体而言,为方便地构造以时间为代价函数的优化问题,首先对系统运动学模型进行相应的变换;在此基础上,考虑包括两级摆角及台车速度和加速度上限值在内的多种约束,构造出相应的优化问题;然后,利用高斯伪谱法(Gauss-pseudospectral method, GPM)将该带约束的优化问题转化为更易于求解的非线性规划问题,且在转化过程中,可以非常方便地考虑轨迹约束.求解该非线性规划问题,即可得到时间最优的台车轨迹.不同于已有的大多数方法,该方法可获得全局时间最优的结果.最后,通过仿真与实验结果验证了这种时间最优轨迹规划方法具有满意的控制性能.     

基于能量耦合的欠驱动三维BC防摆控制

针对桥式起重机运行过程中,台车加速度变化引起的负载摆动问题,提出了一种用于欠驱动三维桥式起重机系统的能量耦合非线性控制方法.方法基于定绳长三维桥式起重机系统,引入负载空间位移误差信号,增强小车运动与负载摆动之间的耦合关系,构造新型的能量函数,设计了一种能量耦合的控制律;并且利用李雅普诺夫方法和拉萨尔不变性定理证明闭环系统的稳定性,能够实现台车定位与负载消摆功能.通过仿真结果分析,上述方法能够有效抑制负载摆动,实现台车定位,与传统PID控制和系统能量控制相比,具有更好的防摆控制效果.     

基于微分平坦理论的桥式起重机轨迹规划北大核心CSCD

针对桥式起重机工作过程中小车的精确定位和负载摆动抑制的问题,文章提出了一种新颖的轨迹规划方法。具体而言,基于微分平坦技术,首先定义了系统的平坦输出,以处理有效载荷摆动和小车运动之间的耦合关系,其次,考虑到连续性和平滑性的要求,将平坦输出信号参数化为多项式曲线。这时各种约束条件均可以转化为对平坦输出的约束,问题得以简化。随后,利用粒子群优化算法求得最佳参数,以实现期望的轨迹。仿真结果表明,本文提出的针对桥式起重机的轨迹规划方法取得了满意的控制性能。     

一种直接基于摆角约束的欠驱动桥式吊车轨迹规划方法

针对非线性桥式吊车系统,本文提出了一种新颖的基于摆角约束的轨迹规划方法.为了提高运送过程的效率和安全性,论文设计了期望轨迹以实现如下优点: 1)使台车很快到达目标位置; 2)将负载摆角抑制到可接受的范围之内; 3)当负载在目标位置停止时无残余摆动.具体而言,所设计的轨迹由三个阶段构成,每一阶段均根据抗摆和零残余摆角的要求来构造摆角曲线,在此基础上,利用桥式吊车的非线性运动学方程分析得到台车轨迹.论文引入了一种优化机制对运送时间,最大摆角等指标进行折衷考虑.文中通过仿真和实验结果表明了所设计的直接基于摆角约束的轨迹规划方法的性能.     

伴有初始负载摆角的桥式起重机能量防摆控制

桥式起重机是一种广泛应用的大型搬运设备,在实际工作过程中,台车运动时会产生伴有初始负载摆角的负载摆动,影响工作效率并带来安全隐患.针对这种情况,设定期望的台车误差轨迹和摆角误差轨迹,将桥式起重机动力学模型转换为误差跟踪动力学模型,提出一种基于能量分析方法的桥式起重机防摆控制策略.通过LaSalle不变性原理和Lyapunov方法对闭环系统的稳定性进行理论分析.仿真与实验结果表明,所提防摆控制方法的控制性能几乎不受初始负载摆角的影响,可以保证桥式起重机在无初始负载摆角和带有初始负载摆角的情况下都能取得良好的控制效果,能够驱动台车准确到达目标位置,有效抑制并快速消除负载摆角,同时对外部扰动具有很强的鲁棒性.     

平面四旋翼无人飞行器运送系统的轨迹规划与跟踪控制器设计

对于四旋翼无人飞行器运送系统而言,需要保证飞行过程中负载的摆幅维持在适当的范围内,并且在飞行器到达目的地后负载无残余摆动.本文针对四旋翼无人飞行器运送系统,提出了一种新颖的轨迹规划与跟踪控制方法.论文首先得到了平面四旋翼无人飞行器的运动特性与负载摆角之间的非线性耦合关系.通过相平面内的几何分析,分别设计了两个轴方向上的分段式加速度轨迹.这种轨迹具有简洁的解析表达式并可获得较高的运送效率,同时满足飞行器的速度,加速度等物理约束.为了使四旋翼无人飞行器准确跟踪规划好的轨迹,本文基于反步法设计了一种非线性跟踪控制器,并通过李雅普诺夫方法对其闭环稳定性进行分析,证明其能使跟踪误差指数收敛于零.论文最后通过仿真结果验证了本文所提出方法的可行性与有效性,及其对外界干扰的鲁棒性.     

基于能量强耦合的双摆型塔机消摆控制北大核心CSCD

为解决非线性双摆型塔式起重机欠驱动系统负载两级摆动幅值大、定位精度不高、抗干扰能力差的问题,基于能量强耦合的分析方法研究了塔式起重机转臂转动与两级摆角摆动之间的耦合关系,设计了一种防摆控制器,并通过李雅普诺夫方法和拉萨尔不变性原理证明了系统的稳定性。仿真实验结果表明,与其他应用广泛的控制方法相比,所提控制策略明显提升了负载的运送效率,有效地抑制了负载的两级摆角,消除了残余摆角,并且控制驱动力矩不会对系统造成冲击;在系统参数、目标位置变化和加入综合性外界干扰时,控制器具有优良的鲁棒性。所提控制策略具有良好的适应性和控制性能。     

欠驱动桥式吊车消摆跟踪控制

对于桥式吊车系统而言,其控制目标是将货物快速、精确、摆动尽可能小地运送到目标位置.为此,本文提出了一种新型的轨迹跟踪控制策略,可在保证负载快速平稳运送的同时,有效地抑制并消除整个过程中负载的摆动.具体而言,通过对吊车动力学模型进行一系列的变换,设计了一种新颖的跟踪控制器,并对闭环系统信号的有界性与收敛性进行了理论分析.与调节控制方法相比,本文方法可保证台车的平滑启动与运行;此外,本方法放宽了已有轨迹跟踪控制方法对参考轨迹的约束条件,更具实用性与一般性.实验结果表明,本文设计的控制器能取得优于已有方法的控制效果,并对外界干扰具有很强的鲁棒性.     

深海起重机系统的实时轨迹规划方法

近年来, 随着海洋资源的不断开发与海洋工程的全球化推进, 深海起重机得到了广泛应用, 其控制问题也引起研究人员的极大关注. 在深海作业环境中, 由于吊运过程受到水流作用力的影响, 负载摆动幅度增大, 系统状态量间非线性耦合关系增强, 使系统控制难度加大. 为此, 本文针对深海起重机系统提出了一种实时轨迹规划方法. 具体而言, 通过分析系统动力学特性和状态变量之间复杂的耦合关系, 提出了一种实时规划轨迹的方法, 并从理论上证明了该方法可在使台车准确快速到达指定位置的同时, 有效抑制负载摆动. 最后, 一系列仿真结果证明了所提方法的良好性能.     

Kinematic coupling-based trajectory planning for rotary crane system with double-pendulum effects and output constraints

When the payload is too large or the hook mass cannot be ignored, the double-pendulum phenomenon may happen in rotary cranes practical applications. The increase in dynamic complexity makes it more difficult to fast and accurate positioning while suppressing swing during cargo transportation. Moreover, output constraints should be considered in actual crane systems. In this paper, a novel kinematic coupling-based trajectory planning method is proposed for double-pendulum rotary cranes with the constraints on angular acceleration and velocity of the boom. The proposed trajectory consists of two parts: a positioning reference component and a swing-eliminating component. The positioning reference trajectory takes into account the physical constraints of the actuator. The swing-eliminating trajectory is designed based on the kinematic coupling relationship among the boom luffing, the hook swing and the payload swing. Lyapunov techniques and Barbalat lemma are used for stability analysis. Numerical simulation and real experiments verify the superior control performance and robustness of the proposed control method.     

Inverse motion planning method for overhead crane systems with state constraints

The trajectory planning problem with state constraints of overhead crane systems is considered in this paper. A new method, that is, an inverse motion planning method, is proposed. On this basis, a new trajectory planner is designed. The payload swing angle trajectory is designed first, and then by substituting it into the dynamic equations, the trolley trajectory is derived. For any transportation tasks, the adjustable parameter of the planner is computed by solving the state constraints such that the system states; that is, the trolley acceleration, trolley speed, and payload swing angle will not exceed their predefined constraints. Several experimental tests are conducted to verify the swing elimination performance of the proposed method.     

An Enhanced Coupling Nonlinear Tracking Controller for Underactuated 3D Overhead Crane Systems

An enhanced coupling nonlinear tracking control method for an underactuated 3D overhead crane systems is set forth in the present paper. The proposed tracking controller guarantees a smooth start for the trolley and solves the problem of the payload swing angle amplitude increasing as the transferring distance gets longer for the regulation control methods. Different from existing tracking control methods, the presented control approach has an improved transient performance. More specifically, by taking the operation experience, mathematical analysis of the overhead crane system, physical constraints, and operational efficiency into consideration, we first select two desired trajectories for the trolley. Then, a new storage function is constructed by the introduction of two new composite signals, which increases the coupling behaviour between the trolley movement and payload swing. Next, a novel tracking control strategy is designed according to the derivation form of the aforementioned storage function. Lyapunov techniques and Barbalat's Lemma are used to demonstrate the stability of the closed‐loop system without any approximation manipulations to the original nonlinear dynamics. Finally, some simulation and experiments are used to demonstrate the superior transient performance and strong robustness with respect to different cable lengths, payload masses, destinations, and external disturbances of the enhanced coupling nonlinear tracking control scheme.     

一种直接基于摆角约束的欠驱动桥式吊车轨迹规划方法（英文）

This paper proposes a novel swing constraint-based trajectory planning method for nonlinear overhead crane systems.To enhance the efficiency and security of the transportation process, some desired trajectories are designed to achieve the following merits: 1) leading the trolley to reach the destination sufficiently fast; 2) keeping the payload swing in an acceptable domain;3) eliminating the residue swing when the trolley stops at the desired position. Specifically, the trajectories are divided into three stages. For each stage, the desired curve of the swing angle is directly constructed in accordance with anti-swing and zero-residual swing requirements, based on which the trolley trajectory is then obtained by analyzing the nonlinear kinematics of the crane system.An optimization mechanism is introduced to make intelligent compromises among the indices of transportation time, maximal swing angle, and so on. Both simulation and experimental results are provided to demonstrate the performance of the proposed direct swing constraint-based trajectory planning method.     

Nonlinear Anti-swing Control of Underactuated Tower Crane Based on Improved Energy Function

The control system of tower crane exhibits strong nonlinearity in the process of control execution, which is prone to the problems of inaccurate positioning control of the payload and difficult anti-swing control. Aiming at the problems, this paper proposes a control law based on improved energy coupling analysis for suppressing the payload swing in the tower cranes. A three-dimensional dynamic model of tower crane system with considering friction is established, and an improved energy coupling signal is designed. The coupling relationship of trolley movement and payload swing, jib rotation and payload swing are considered, then a nonlinear anti-swing controller is established in order to reduce the swing. The closed-loop stability of the system with the controller is verified by the Lyapunov method and LaSalle invariance principle, simulations and experimental analyses are performed to verify the controller performance. The control performance of the controller is compared with other classic and typical current control methods, and the proposed controller outperformed other controllers. The anti-swing controller proposed in this paper has accurate positioning, and can achieve precise control when the payload is transported, reaching the set target position in a little time and eliminating residual swing angle. Meanwhile the proposed controller has a good control robustness, which can restore stability in around a very short time when the rope length and payload mass of the system’s inherent property are changed and external interference is added. In addition, when different target position parameters are uncertain, the proposed control law has good robust performance.

     

An efficient online trajectory generating method for underactuated crane systems

In this paper, a trajectory planning approach is proposed for underactuated overhead cranes. Different from existing trajectory planning methods, the presented approach generates trajectory commands online without the necessity of iterative optimization, which is convenient for practical implementation. We demonstrate the performance of the proposed method, including swing elimination and precise trolley positioning, with rigorous Lyapunov‐based mathematical analysis. Both numerical simulation and experimental results suggest that the presented method is feasible and efficient for practical applications. Copyright © 2013 John Wiley & Sons, Ltd.