【作者】 方海涛；

【导师】 邓宗全；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2009， 博士

【摘要】 根据多关节式月球车的机构特征和多电机独立驱动下多运动模式协调运动控制强实时性、高稳定可靠的要求,本文开展了基于RTAI(Real-Time Application Interface,实时应用接口)的开放式月球车运动控制平台及其相关关键技术的研究,并对实时Linux下车轮的伺服特性和苛刻地形中基于RTAI的月球车协调运动关键实现方法展开了深入研究,为基于Linux的实时多任务运动控制平台在航天工程中的应用提供基础。首先以多关节式六圆柱-圆锥轮式月球车为研究对象,根据此类月球车的机构特点,提出一种基于月面地形特征的非结构化地形分类法的多运动模式运动控制策略。将多关节式月球车的运动模式分为被动适应地形运动模式、轮步运动模式、主动越障运动模式及跨越壕沟运动模式。分析不同运动模式在复杂月面地形中运动的特点及多模式运动规划方法,并在此基础上建立了在月球车车体和运动关节的运动坐标系下极端复杂地形中月球车运动学模型,为多关节独立驱动月球车的实时协调控制技术奠定了基础。以开源系统Linux为平台,通过所开发的软件完成运动控制的所有工作,为减小系统硬件的复杂性和提高系统的可靠性,构建一种基于RTAI,采用软运动控制方案构建的强实时运行平台。根据月球车控制系统和RTAI的特点,开发基于RTAI的开放式月球车系统平台。以线程合作模型为基础,用RTAI线程建立了月球车系统多任务结构模型。深入讨论了基于RTAI的月球车控制系统通信的实现方法,以指令中继转发的方式简化月球车系统的通信结构。最后以多关节式月球车为例,实现了基于RTAI操作系统平台的月球车控制系统,为基于RTAI的开放式实时平台在月球车控制系统中的应用提供了应用实例。为进一步探求基于RTAI的实时运动控制平台的性能和实现方法的便捷性,提出了一种基于RTAI-Lab技术的实时控制系统设计方法,并以此作为开发运动控制算法的原型设计工具,减少系统设计周期和提高系统设计可靠性。为验证RTAI纯软件硬实时运动控制的实时性,研究了RTAI的实时延时性和抖动性对电机控制的影响。然后以多关节式月球车为研究对象,对月球车多轮独立驱动下的协调控制的实时RTAI模型进行了研究。着重研究了多关节多轮独立驱动月球车协调控制的实时RTAI实现技术。针对月球车控制系统平台的要求,以实时多任务为目标,给出了通用性平台提高实时性的实现方法,主要对开源系统Linux下实时多任务平台的中断处理器和任务调度器的设计和实现方法等,并提出了基于驱动程序和软中断通信机制的两种实时通信方法,为基于实时操作系统的多任务开放式平台的实现提供理论依据。构建基于RTAI的多关节六圆柱-圆锥轮式月球车运动控制实验平台,对月球车在被动适应地形的运动模式、轮步运动模式、主动越障模式及跨越壕沟运动模式下,基于RTAI的运动控制平台及普通Linux下的运动控制平台的耗时和运动精度进行测试,验证基于RTAI的多关节式月球车运动控制的正确性。结果表明,与普通Linux下多关节式月球车运动控制平台相比,基于RTAI的月球车控制平台耗时得到了较大幅度的较少,且运动精度更高。更多还原

【Abstract】 Because the multi-task lunar rover motion control system has the requirements of high real-time performance and system reliability, this dissertation carries out the research on the real-time motion control platform of the lunar rover and the related technology based on the RTAI (Real-Time Application Interface), aiming at the characteristics of multi-jointed rover mechanism and multi-wheel coordinated control. And the rover wheel servo characteristics and coordinated control implementation with RTAI are researched to give the foundation for the application of open platform of control system in the aerospace industry with RTAI.Taking the multi-jointed lunar rover with six cylinder-conical wheels as the research object, multi-mode motion control strategy is put forward, based on the classification of the unstructured lunar surface attributes and the rover mechanical characteristics. The motion modes can be divided into: passive terrain adaptation motion mode, wheel-walking motion mode, active passing obstacle motion mode and crossing ditch motion mode. The application and planning of these motion modes are analyzed and kinematics models of the rover motion on complicated uneven landform are set up, which lay the solid foundation for the multi-wheel coordinated control.To achieve the real-time requirement of the rover motion control system, this dissertation researches the method of improving real-time performance of the general OS, put forward the design and implementation of the interrupt processor and task scheduler of the real-time multi-task platform based on open sourced Linux, and set up the inter-task communication with method of device driver and soft interrupt mechanism, which give the theory guideline and useful reference for the realization of real-time multi-task platform based on the real-time OS.To realize the soft motion control which can reduce the hardware design complexity and improve system reliability, this dissertation put forward soft motion control platform based on RTAI, which has hard real-time performance. Based on the characteristics of rover motion control structure and RTAI, the implementation technology of open motion control system platform is researched, its multi-task model is realized with the RTAI real-time thread based on the threads cooperation model. The communication structure of lunar rover motion control is simplified with the command relay-transmit mode, by the analysis of RTAI communication.As an application example, open real-time control platform based on RTAI is realized in the motion control of multi-joint six cylinder-conical-wheel lunar rover. Effective motor control is import for the motion control system, so for the sake of research of performance evaluation and easy implementation of real-time motion control, a design method of real-time application based on RTAI-Lab is put forward, which can be used to save time spending and improve development reliability. To research the performance of the software hard real-time motion control system, the influence of delay and jitter on motor control is researched. Taking the lunar rover with six cylinder-conical wheels as example, this dissertation researches the coordinated control of multiple independent driven wheels to achieve the optimization of driving efficiency and locomotion accuracy.The real-time motion control system of six cylinder-conical-wheel lunar rover prototype based on RTAI is setup, and motion experiments are carried out. These experiments demonstrate the validation of the designed multi-wheeled coordinated motion control system and prove its feasibility.更多还原