复杂地形环境中四足机器人行走方法研究

发布时间：2018-01-11 08:04

本文关键词：复杂地形环境中四足机器人行走方法研究　出处：《山东大学》2016年博士论文　论文类型：学位论文

【摘要】：地球陆地表面有超过50%以上的面积都是崎岖不平的山地、陡坡、沼泽等,轮式或履带式机构均无法在这些地形中移动。然而,许多陆生四足哺乳能够在崎岖度较高的地形中灵活自如地行走,它们在负重能力、复杂地形适应性、运动灵活性以及能量利用率等方面都具有极大的优势。以四足哺乳动物为仿生对象开发的四足机器人既有比双足机器人更高的稳定性又避免了多足机器人机构的复杂性,因而,从制造成本、控制难易程度和稳定性等方面综合考虑,四足机器人为最佳的腿足式机器人形式。鉴于四足机器人所具有的诸多优点,其在地形勘测、工程探险、救灾救援、军事侦察、环境监测等领域具有广阔的应用前景。四足机器人自身机械结构复杂,是一个非线性多体系统动力学系统。因此,构造具有大负载能力、高动态性和环境适应性的高性能四足机器人需要在机械结构设计、运动学分析、稳定性评价方法、步态规划、足力控制、系统集成等方面有所突破。论文主要围绕如何提高四足机器人的环境适应性和运动稳定性,通过研究四足机器人的结构和运动特点,提出了一系列步态生成方法,主要包括以下几方面内容：1、实现单关节对给定信号的准确跟随是四足机器人运动控制的基础。本文在分析四足机器人拓扑结构的基础上,建立了机器人的运动学模型,并提出了一种基于速度前馈的四足机器人单关节伺服控制器,通过将期望轨迹经由雅克比矩阵获得的期望的关节角速度作为伺服系统的前馈,有效地改善了四足机器人关节伺服系统的性能。2、为了保证四足机器人在一般崎岖地形中稳定地行走,本文提出了一种连续静步态的生成方法。在四足机器人的行走过程中,规划其躯干平行于水平地面且以一定的速度连续地向前运动,这样,能够在简化步态生成的同时提高机器人的平均运动速度；通过增加四足支撑相中的重心摆动,机器人稳定性得到有效地提高；另外,本文中给出了摆动足足底运动轨迹规划方法,能够保证摆动足准确地运动至目标落足点。3、当四足机器人使用非连续步态行走时,虽然其平均运动速度较低,但能够获得较高的稳定裕度。本文提出了一种四足机器人非连续静步态的规划方法。该方法包括姿态调整规划、躯干运动曲线规划以及摆动足足底轨迹规划三部分。通过对这三部分的规划,有效地保证了四足机器人在行走过程中的稳定性,进而提高了四足机器人的地形适应性。4、自然地形中往往包含不适于四足机器人落足的区域,当在这类地形上行走时,四足机器人需要使用一种名为自由步态的非周期性的静步态。本文给出了一种连续自由步态的规划方法。基于地形中提前已知的可选落足点位置,四足机器人在行走过程中,能够自主选择迈步顺序,并为摆动足选择最优落足点；通过重心的摆动,四足机器人能够保证其在行走过程中的稳定裕度不小于最小稳定裕度。使用本文中提出的连续自由步态,四足机器人能够自主、稳定、快速地通过包含不可落足区域的崎岖地形。5、通过力控制方法的应用,可以提高四足机器人在行走过程中的步态柔顺性,进而保证四足机器人在崎岖地形上的稳定性。本文着重研究了四足机器人在使用静步态/自由步态行走时的力控制方法,详细分析了基于动力学模型的力控制方法和基于PD的力控制方法,并给出了基于足力分配的力控制方法以及基于阻抗控制的力控制方法。通过这些方法的应用,实现了四足机器人的力控制,使四足机器人获得了更加优秀的性能。
[Abstract]:The land surface of the earth are more than 50% of the area is rugged and mountainous, steep slope, swamp, wheeled or tracked institutions are unable to move on this terrain. However, many terrestrial mammalian quadruped can walk in the high degree of rugged terrain flexibly, their weight capacity, adaptability to complex terrain, all has the great advantage of the flexibility of movement and energy utilization and other aspects. In mammals of quadruped bionic quadruped robot developed both more stability of the biped robot and avoids the complexity of multi legged robot mechanism, therefore, the manufacturing cost control, the degree of difficulty and stability consideration for quadruped robot the best form of legged robot. In view of the many advantages of the quadruped robot has, in terrain surveying, engineering exploration, disaster rescue, military reconnaissance, environmental monitoring and so on. The domain has a wide application prospect. The quadruped robot mechanical structure is complex, is a nonlinear dynamic system of multibody system. Therefore, structure has a large load capacity, in mechanical structure design, kinematics analysis of a quadruped robot needs high performance high dynamic and environmental adaptability, stability evaluation method, gait planning, force control, system integration as a breakthrough. This thesis mainly focuses on how to improve the environmental adaptability and motion stability of quadruped robot, the structure and motion characteristics of quadruped robot, put forward a series of gait generation method, it mainly includes the following aspects: 1, to achieve a single joint of a given signal accurately is the basis of quadruped robot motion following control. In this paper based on the analysis of topological structure of quadruped robot, establish the kinematics model of the robot, and propose a method based on speed Quadruped robot joint servo controller of single feedforward, the desired trajectory through the Jacobian matrix obtained the desired angular velocity as a feedforward servo system, and effectively improve the performance of.2 quadruped robot joint servo system, in order to ensure the stable walking of quadruped robot in rough terrain, this paper presents a continuous static gait generation method. In the running process of quadruped robot, planning the torso parallel to the ground and continuously at a certain speed to move forward, so, to simplify gait generation and improve the average movement speed of the robot; by increasing the center of gravity of the swing phase stability of quadruped robot support, has been effectively improved; in addition, this paper gives a full swing bottom trajectory planning method, can guarantee the swing foot accurately to the target footholds when.3. The use of non continuous gait of quadruped robot, although the average velocity is low, but can get a higher margin. This paper proposes a quadruped robot planning method for continuous non static gait. The method includes attitude adjustment planning, planning and trunk movement curve for bottom swing trajectory planning. Based on the three part the three part of the plan, and effectively ensure the stability of the quadruped robot in the process of walking, so as to improve the adaptability of terrain.4 quadruped robot, natural terrain often contain areas not suitable for quadruped robot foot, when walking in this type of terrain, quadruped robot needs static gait using a kind of non periodic free gait planning method. This paper gives a continuous free gait. Optional terrain ahead of the known foot position based on quadruped robot through the process. In order to be able to choose the move, foot and choose the optimal footholds for swing; through the gravity swing, quadruped robot can ensure the process of walking stability margin is not less than the minimum stability margin. The use of continuous free gait is presented in this paper, the quadruped robot can be independent, stable, fast by including the rugged the terrain.5 may not fall foot area, through the force control method is used, can improve the flexibility of gait of quadruped robot in the process of walking, so as to ensure the stability of the quadruped robot in rough terrain. This paper focuses on the research of the quadruped robot in static gait / free gait when the force control method is analyzed in detail. Control method and control method based on PD force based on the dynamic model, and puts forward the control method of the force and the foot force distribution based on impedance control based on force control method. Through the application of these methods, the force control of the quadruped robot has been realized, which makes the quadruped robot get better performance.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP242

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