Nonlinear dynamic fractional sliding mode control to the motor of mining locomotive

The harsh operating environment and complex operating conditions of the mine electric locomotive affect the control performance of the locomotive traction motor.In order to improve the speed control performance of electric locomotive traction motors,a dynamic fractional-order sliding mode control(DFOSMC)algorithm considering uncertain factors was proposed.A load torque sliding mode observer was designed for the complex load disturbance of the traction motor,and its observations were integrated into the DFOSMC controller to overcome the influence of load disturbance.Finally,the stability of the designed controller was proved by Lyapunov's theorem.Besides,the control performance of DFOSMC controller was compared with integer-order sliding mode controller and fractional-order sliding mode controller through simulation experiments.Compared with integer-order sliding mode and fractional-order sliding mode controllers,the dynamic and static performance of the DFOSMC controller with load observation is better,and it has stronger anti-interference ability.The DFOSMC controller effectively improves the control performance of the traction motor of the mining locomotive.

A novel speed sensor-less direct torque control system for mining locomotive haulage

A novel speed sensor-less direct torque control induction motor drive system for the mining locomotive haulage is presented in the paper. Rotor speed identification is based on the model reference adaptive control theory with neural network using back propagation algorithm. The system is implemented using a real-time TMS320F240 digital signal processor. The simulation study and experiment results indicate that the suggested system has good performance.

Typical faults and safety analysis of brake controller for AC locomotive

Purpose–The brake controller is a key component of the locomotive brake system.It is essential to study its safety.Design/methodology/approach–This paper summarizes and analyzes typical faults of the brake controller,and proposes four categories of faults:position sensor faults,microswitch faults,mechanical faults and communication faults.Suggestions and methods for improving the safety of the brake controller are also presented.Findings–In this paper,a self-judgment and self-learning dynamic calibration method is proposed,which integrates the linear error of the sensor and the manufacturing and assembly errors of the brake controller to solve the output drift.This paper also proposes a logic for diagnosing and handling microswitch faults.Suggestions are proposed for other faults of brake controller.Originality/value–The methods proposed in this paper can greatly improve the usability of the brake controller and reduce the failure rate.

Locomotion Optimization and Manipulation Planning of a Tetrahedron-Based Mobile Mechanism with Binary Control

Locomotion and manipulation optimization is essential for the performance of tetrahedron-based mobile mechanism. Most of current optimization methods are constrained to the continuous actuated system with limited degree of freedom(DOF), which is infeasible to the optimization of binary control multi-DOF system. A novel optimization method using for the locomotion and manipulation of an 18 DOFs tetrahedron-based mechanism called 5-TET is proposed. The optimization objective is to realize the required locomotion by executing the least number of struts.Binary control strategy is adopted, and forward kinematic and tipping dynamic analyses are performed, respectively.Based on a developed genetic algorithm(GA), the optimal number of alternative struts between two adjacent steps is obtained as 5. Finally, a potential manipulation function is proposed, and the energy consumption comparison between optimal 5-TET and the traditional wheeled robot is carried out. The presented locomotion optimization and manipulation planning enrich the research of tetrahedron-based mechanisms and provide the instruction to the successive locomotion and operation planning of multi-DOF mechanisms.

Locomotion and Depth Control of Robotic Fish with Modular Undulating Fins

This paper presents an environmental-friendly robotic system mimicking the undulating fins of a fish.To mimic the actual flexible fin of real fish,a fin-like mechanism with a series of connecting linkages is modeled and attached to the robotic fish,by virtue of a specially designed strip.Each link is able to turn and slide with respect to the adjacent link.These driving linkages are then used to form a mechanical fin consisting of several fin segments,which are able to produce undulations,similar to those produced by the actual fish fins.Owing to the modular and re-configurable design of the mechanical fin,we are able to construct biomimetic robotic fish with various swimming modes by fin undulations.Some qualitative and workspace observations by experiments of the robotic fish are shown and discussed.

3-D Locomotion control for a biomimetic robot fish

This paper concerns with 3-D locomotion control methods for a biomimetic robot fish. The system architecture of the fish is firstly presented based on a physical model of carangiform fish. The robot fish has a flexible body, a rigid caudal fin and a pair of pectoral fins, driven by several servomotors. The motion control of the robot fish are then divided into speed control, orientation control, submerge control and transient motion control, corresponding algorithms are detailed respectively. Finally, experiments and analyses on a 4-link, radio-controlled robot fish prototype with 3-D locomotion show its good performance.

Mechanical design and locomotion control of a homogenous lattice modular self-reconfigurable robot

In this paper, we propose a novel, 3D, like cubic shape, modular self-reconfigurable (MSR) robot named M-Cubes. Its key mechanical components are analyzed in detail. By communicating with the neighboring modules, each unit employs its automatic lock device composed of a pin and a hole on each connection plane which can connect or disconnect with neighboring modules. The M-Cubes system consisting of many identical modules cooperates to change their connection, and then the whole structure transforms into arbitrary structure. Furthermore, we describe its locomotion control based on the driving function and the adjacency matrix which is effective for solving the computationally difficult problem and optimizing the system motion path during the self-reconfiguration process. Finally, a simulation experiment using java 3D technology, proved the new method for controlling modular robot is robust and useful.

Inter-limb and intra-limb coordination control of quadruped robots

To realize the coordinated and stable rhythmic motion of quadruped robots （QRs）, the locomotion control method of QRs based on central pattern generator （CPG） was explored. In tradi- tional control strategies based on CPG, few CPG models care about the intra-limb coordination of QRs, and the durations of stance phase and swing phase are always equal. In view of these deficien- cies, a new and simpler multi-joint coordinated control method for both inter-limb and intra-limb was proposed in this paper. A layered CPG control network to realize the locomotion control of QRs was constructed by using modified Hopf oscillators. The coupled relationships among hip joints of all limbs and between hip joint and knee joint within a limb were established. Using the co-simulation method of ADAMS and MATLAB/Simulink, various gait simulation experiments were carried out and the effectiveness of the designed control network was tested. Simulation results show that the pro- posed control method is effective for QRs and can meet the control requirements of QRs＇ gaits with different duty factors.

Design of trotting controller for the position-controlled quadruped robot

This work presents a controller designed for position-controlled quadrupedal dynamic locomotion,aiming at simple and robust trotting control. The controller takes the torso attitude angles and velocities into planning foot trajectories. Firstly design of the servo motor actuated quadruped robot is introduced and the kinematic equations are deduced. Then a scheme is presented for controlling the robot torso attitude based on the virtual leg model. Furthermore,it demonstrates the design of the controller which enables the robot to have a wide range of trotting gaits and omni-directional motions. Finally,results of robust trotting in various speeds,path tracking and push recovery in simulation are reported,and results of trotting on real quadruped robots will be studied.

Kinematic Control of Wheeled Snake-Like Mobile Robot

From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake like mobile mechanism. On the hypothesis of the existing non holonomic constraints on the robot kinematics, we set up the relationship among the kinetic control parameters in the snake like movement using Lie group and Lie algebra of the principle fiber bundle and provide some theoretical control methods to realize the snake like locomotion.

重载机车风源系统智能控制研究

针对重载机车提速运行过程中空气中不断扬起的粉尘对风源系统中处理的空气的质量提出了更高的要求。当压缩空气中粉尘颗粒浓度高或压缩空气湿度过大时,使得制动设备无法正常工作甚至损坏,给重载机车的平安行车带来安全隐患。该文通过设计一套智能重载机车风源控制系统,通过智能采集、检测风源系统中空气的洁净度与湿度参数,自动去除压缩空气中的粉尘和水,得到高质量的合格压缩空气,使得处理后的空气的湿度与洁净度符合机车制动系统管路的要求,当处理后的空气不符合要求时发出报警信号,提示工作人员进行排故处理,避免了计划维修的盲目性,提升了风源系统的有效运行效率,保障了重载机车的安全运输。

工矿机车牵引双供电系统及其下垂控制策略

为了应对工矿机车距离和载重日益增长的发展趋势,同时满足工矿机车牵引对突变负荷的运行稳定性提升的要求,提出一种双供电系统及其下垂控制方法的工矿机车牵引供电方案。针对工矿牵引具有负荷突变、往返载荷差异大等工矿行业的特殊性,对比分析了站间精确均流和非精确均流策略对工矿机车牵引的适用性,根据分析结果提出了工矿机车双供电系统方式及其站间协同下垂控制策略,在此基础上引入电流前馈控制策略。搭建了仿真模型和包含牵引变电站的工矿机车低压试验牵引物理动模平台,试验结果表明所该策略在负荷突变工况下的机车电压稳定性显著优于与常规下垂控制方法。该研究为工矿机车牵引向大容量、远距离、高可靠性未来发展提供了有力的技术支撑。

零速信号在机车电气控制中的应用

随着机车电气控制技术的不断发展,零速信号在机车电气控制中扮演着重要的角色,零速信号是指机车制动或牵引系统中用来检测车辆是否处于零速状态的信号,它能够帮助系统实时监测车辆的运行状态,从而实现精确的控制和调节,文章探讨了零速信号在机车电气控制中的应用,希望能够为机车电气的控制发展提供借鉴。

复杂地形下轮腿复合机动平台动态运动控制

复杂地形环境下质心参考轨迹的动态精确跟踪是保障轮腿复合机动平台稳定执行各项任务的关键。为提升平台的地形适应能力与位姿跟踪能力,提出一种动态运动控制策略。综合地形因素,建立包含车轮动力学的单刚体动力学模型,并通过近似简化将系统动力学模型转化为状态空间方程的标准形式。考虑车轮与腿部耦合运动,提出一种基于前馈力矩与反馈力矩的混合运动控制方法。通过二次规划算法求解最优地面反作用力,利用雅克比矩阵将作用力映射至关节以获取前馈力矩。为避免由环境引起的外部扰动造成系统无法在较短时间内完成优化计算,引入关节力矩反馈控制及时修正位姿跟踪误差,使系统能够快速准确地响应外部扰动,有效提高系统的鲁棒性和稳定性。仿真结果表明,新方法可有效提升平台在复杂地形下位姿动态跟踪精度,保障平台平稳运行,为复杂地形下轮腿复合机动平台的工程应用提供有力支撑。

重载机车无模型黏着预测控制研究

重载机车牵引动力的有效发挥依赖于轮对和钢轨接触时形成的黏着力,然而,由于重载机车黏着过程动力学非线性强、变量耦合多、最优蠕滑速度检测难,导致传统控制方法难以对黏着进行高效控制。针对该问题,提出一种无模型黏着集成预测控制方法。首先,分析传统无模型方法存在的问题,建立重载机车蠕滑速度新型扩张超局部模型。其次,设计扩展滑模观测器估计超局部模型中的不确定部分,不同于传统观测方法,该观测器能够“一步式”估算机车当前的黏着系数和蠕滑速度;同时引入一种改进的后调制无稳态振荡极值搜索方法并进行收敛性分析,在有效黏着系数观测的基础上实时寻优期望蠕滑速度。再次,基于最优蠕滑速度极值搜索设计一种离散蠕滑速度预测控制器,避免传统的控制律设计中引入蠕滑速度微分导致的噪声放大问题,并证明闭环控制下的系统稳定性。最后,与传统滑模黏着控制策略进行仿真对比,印证本文所提控制框架能有效降低黏着控制策略设计的复杂度,提升控制转矩的平滑度。在轨面条件突变的情况下,改进无稳态极值搜索方法能够准确搜索适合的最优蠕滑速度,在3种预设工况下都能够准确锁定最优值;离散黏着控制律能够更为精确地控制驱动转矩,与传统的带有蠕滑速度微分的黏着控制律相比极大地降低了转矩抖振。由此可知,该重载机车无模型黏着预测控制方法能够充分发挥黏着系统效能,实现多工况瞬变下的高效黏着控制。

基于语音交互的四足机器人多模式控制实验设计

针对四足机器人全向运动控制、步态与行为切换、人员跟随、自主导航等多模式运动中的人机交互难题,设计了1套基于语音识别与指令解析的四足机器人交互控制系统。明确了四足机器人语音交互系统的硬件组成,并搭建了包含语音采集、识别、解析、播报一体的交互模块;基于SOFM网络设计了语音识别算法;基于ROS建立了语音模块与机器人运动控制模块的通信交互机制,实现了语音指令下达与机器人状态信息播报反馈。通过一系列四足机器人语音交互控制实验,验证了在动态场景下机器人的语音识别准确率高于85%,而在静态场景下则超过95%,保障了四足机器人不同运动模式的准确运动控制。

基于ROS的蛇形机器人控制系统设计

蛇形机器人具有超冗余度的躯干结构和多样化的移动步态。为验证其控制算法,需要一个稳定可靠且具备强扩展性的控制系统。设计开发了一种由正交关节单元组成的蛇形机器人,并提出基于ROS(Robot Operating System)的控制系统设计方案。该方案将控制系统分为应用层、决策层和运动控制层,各层之间分工明确且耦合性低,从而提高了系统的稳定性和扩展性。采用曲线离散法规划蛇形机器人的运动步态,并进行蜿蜒运动和侧移运动测试。实验结果表明,该运动控制策略对机器人有效且设计方案具有可行性和实用性。

基于DSP的锂电池充电供电控制系统设计

为满足电力机车在无电区的供电需求,同时兼顾锂电池(磷酸铁锂)的自动充电、供电要求和环境温度要求,本文在锂电池的充电和供电的需求基础上,设计了基于DSP的锂电池控制系统,对控制系统的总体设计、硬件电路、控制算法和程序等进行介绍,实现了锂电池充电以及供电的自动化运行策略。实验证明:本文设计的锂电池控制系统可有效满足锂电池充电和供电的要求,具有较好的实用性和可靠性。

弱引力下的六足机器人附着与移动控制方法

针对小天体上弱引力带来的脱附难题,研究了适用于小天体星表弱引力环境的六足机器人附着与移动控制方法。建立了足-地接触动力学模型,分析得到六足机器人实现弱引力条件下附着而不脱离、移动而不打滑的力学约束条件。根据六足机器人的机构特点和移动形式,设计了基于三角曲线的平稳步态规划方法,以抑制移动过程中机器人足端所受的冲击效应;建立了基于末端步态偏置的多足协同主动附着方法,保证机器人对小天体星表的稳定附着。最后,通过一个仿真案例,验证了该控制方法的有效性,为弱引力条件下六足机器人的移动探测任务提供了新思路。

Analysis of the different locomotive wireless multi-traction synchronous control systems for heavy-haul combined trains and their performance

This paper looks at the heavy-haul combined train composed of different types of locomotives and its distributed power control system with a combination of 800 MHz and TD-LTE wireless communication.It analyses some key characteristic parameters that affect the synchronism and communication of the differential wireless multi-traction synchronous control systems for heavy-haul combined trains.At the same time,in order to reduce the latency of instruction and information transfer between different types of locomotives,improve the time-limit certainty of wireless transmission and optimize the control quality of multi-traction control systems for heavy-haul combined trains,a synchronism optimization strategy based on the Markov decision process on the basis of Petri networkconstruction is proposed.Relevant experiments and tests are carried out to verify the effectiveness of the synchronism optimization of the control system,which provides a guarantee for improving the differential wireless multi-traction synchronous control system for combined trains and optimizing train control.