【作者】 徐勤江；

【导师】 李贻斌；

【作者基本信息】 山东大学 ， 控制科学与工程， 2011， 硕士

【摘要】 AWID/AWIS高速高机动机器人是一种新型轮式机器人平台,能够全轮独立驱动和全轮独立转向,具有AWID/AWIS特性的机器人平台具有更多、更灵活的驱动和转向方式,能够提供更多的运动模式(如横向移动、原地转向等多种运动模式),可用于对空间受限的高速、高机动性的轮式机器人的研究,代表了未来高级车辆、军用车辆、无人驾驶车辆和大型轮式移动机器人的发展方向。本文以具有代表性的四轮独立驱动独立转向机器人为研究对象,重点对机器人转向控制系统进行研究。该机器人平台基于4个一体化车轮,可以实现向内90°,向外45°转向,通过电子转向控制器,协调控制各个车轮的角度,实现直行、横移、斜行、常规转向、前后轮转向、绕圆转向共6种运动模式。车轮和方向盘之间没有机械连接,通过电子单元控制车轮控制,属于线控转向方式。本文首先研究了转向技术的发展历史,这是AWID/AWIS机器人平台转向系统稳定、可靠、有效运行的关键,结合我们研制的AWID/AWIS高速高机动机器人平台总体目标,设计了基于CAN总线的分布式控制网络,描述了具体实现过程,并对CAN网络的负载能力及再加载能力进行研究。对起关键作用的电机、执行机构、传感器系统的设计思路和实现方法进行了重点介绍,为以后机器人转向系统结构的研究打下了基础。为使操作者对路面状况和阻力变化有直接感觉,本文对回正力矩的产生进行分析,给出了路感的定义和模拟路感的方法。最后从运动稳定性出发,分析了转向过程中传动比随横摆角速度增益的变化规律,介绍了基于理想传动比的控制策略。本文对转向控制器进行硬件设计和软件设计。控制器需要对转角、转速、电流等信号进行实时采集,因此数字测量处理电路和模拟测量处理电路必不可少,此外,电机的驱动电路,也是转向控制器的关键部分,需要重点设计。为了提高系统的可靠性,引入了冗余概念,在电路中增加了CAN冗余设计,提高系统的容错能力。操作稳定性是平台转向过程的重要指标,本文从运动学角度出发,总结了机器人平台6种运动模式,对前后轮转向过程中的转角、转向半径协调关系进行研究,总结四轮独立转向时转向中心位置的范围,分析了任意半径转向的可能性。从动力学模型出发,研究了横摆角速度、侧向加速度、侧偏角等稳定性指标的时域响应,为进一步研究机器人平台的上层控制提供了思路。最后对本文进行总结,提出了下一步工作的展望。更多还原

【Abstract】 AWID/AWIS high-speed and high-maneuver platform is a new wheeled mobile robot platform with all wheels independent driving and independent steering function. It has more features, more flexible combination of driving and steering, and can provide more sport modes (such as lateral movement, pivot turn and other sport mode).Through this platform we can study the speed and maneuverability in small area. It is the development tendency of vehicle, such as the advanced civil vehicle, military vehicle, unmanned vehicle and wheel mobile robots with high speed ability in the future. This paper puts forward the typical 4WIS/4WID mobile robot as the research target and mainly studies the Steer Control System. The robot has 4 integrated wheels with inside 90°, outside 45°limited angle, controlled by electronic controller with lateral movement, pivot turn and other 4 sport modes. No mechanical connection is existing between wheels and handwheel, therefore it belongs to Steer-By-Wire system.The paper deals with the steer technology at the beginning, which is the basis of the stable and effective operation. With the overall goals of AWID/AWIS, we construct the distributed control network, and the implementation of distributed network is given in detail. Also, the capacity of load and reload of network is analysed carefully in the next. To improve direct feeling of road and resistance, we analyse the cause of lateral force and give a formula to evaluate it. From kinematics stability perspective, we study the regularity for Steering Ratio with change of yaw velocity and introduce an ideal steer radio model.This paper presents software design and hardware design of wheel-controller. Angle velocity, current and position need to be collected realtime, thus digital and analog process circuits are essential in steer-controller. In addition, the driver circuit is also the critical component for motor control. To improve the reliability, redundancy idea is adopted, such as CAN redundancy and interface redundancy.Operational stability is the important guideline for checking and balancing the platform performance when steering. From the kinematics perspective, we summarize 6 sport modes and study the relevances between steer radius and steer angle for research the operational stability. Further more, turning center is given in a limited area. Besides, we analyse the yaw velocity, lateral acceleration, slip angle as steering and give the domain response and steady-state gain, which lays the foundation for following research of stability control.Finally, we conclude this paper and give suggestions for future research.更多还原