Dynamic modeling and step-climbing analysis of a two-wheeled stair-climbing inverted pendulum robot

ABSTRACT

In this study, the control of a two-wheeled stair-climbing inverted pendulum robot and its climbing motion are analyzed and discussed. The robot adopts a state-feedback controller with a feed-forward constant to stabilize the body and achieve step-climbing motion. The control parameter is considered based on the dynamic model motion on a flat surface and the static model of motion on the step. For climbing stairs with a narrow step tread, a constant torque is applied to reduce the space required for recovering the body stability after climbing. The stability of the robot is numerically analyzed by analyzing the orbital stability of its limit cycle. The stability analysis shows that the control method can achieve a stable stair-climbing motion. The effectiveness of the control method is demonstrated through an experiment. The result indicates that the robot can climb the stairs, and the required time for climbing a single step is approximately 1.8?s.     

Development and field test of the articulated mobile robot T2 Snake-4 for plant disaster prevention

Abstract

In this work, we develop an articulated mobile robot that can move in narrow spaces, climb stairs, gather information, and operate valves for plant disaster prevention. The robot can adopt a tall position using a folding arm and gather information using sensors mounted on the arm. In addition, this paper presents a stair climbing method using a single backward wave. This method enables the robot to climb stairs that have a short tread. The developed robot system is tested in a field test at the World Robot Summit 2018, and the lessons learned in the field test are discussed.     

基于传感器信息融合的移动机器人自主爬楼梯技术研究

机器人自主爬楼梯是移动机器人完成危险环境探查、侦察、救灾等任务需要具备的基本智能行为之一.分析了楼梯的多样性和履带式机器人爬楼梯固有的不稳定性导致机器人爬楼梯工作的复杂性,描述了带前导手臂的履带式移动机器人爬楼梯的步骤,简要介绍了利用超声波、视频摄像头和激光扫描测距仪信息来感知楼梯和判断机器人与楼梯相对位置的算法,最后提出了一个基于传感器测量值可信度的信息融合方法进行楼梯参数感知和行驶方向计算的机器人自主爬楼梯的控制系统结构.     

Study on mobile mechanism of a climbing robot for stair cleaning: a translational locomotion mechanism and turning motion

In human living environments, it is often the case that the cleaning area is three-dimensional space such as a high-rise building. An autonomous cleaning robot is proposed so as to move on all floors including stairs in a building. When a robot cleans in three-dimensional space, it needs to turn for direction in addition to climb down stairs. The proposed robot selects movement using legs or wheels depending on stairs or flat surfaces. In this paper, a mobile mechanism and a control method are described for translational locomotion. The translational mechanism is based on using two-wheel-drive type omni-directional mobile mechanism. To recognize a stair using the position-sensitive detector, the robot shifts from translational locomotion to climbing down motion or edge-following motion. It is shown that the proposed robot turns to face a stair with the accuracy of 5°.     

一种多模式全向移动机器人攀爬楼梯的步态

针对移动机器人在户外运动中所遇到的台阶、楼梯等复杂地形,设计了一种可攀爬楼梯的多模式全向移动机器人。通过切换运动模态,该机器人既能像传统移动机器人一样快速移动,又具备了足式机器人的越障能力。首先,分析并构建了多模式全向移动机器人的运动学模型;其次,研究了该机器人越障能力和质心位置之间的关系并计算了该机器人可以翻越台阶的...     

六轮移动机器人爬楼梯能力分析

研究了PBJ-01防暴机器人攀越楼梯的能力. 从机器人对楼梯的几何包容、机器人重心和机器人爬楼梯过程中的最大俯仰角对机器人倾覆的影响等多方面考虑, 得出机器人能够爬越楼梯时楼梯参数必须满足的条件. 在该机器人的行为决策中, 为其选择越障还是避障提供了依据.     

湿吸附机理及其在仿生爬壁机器人中的应用

提出一种新的基于湿吸附机理的仿生爬壁机器人．首先讨论湿吸附模型及吸附力的控制方法,对一种 基于硫化硅橡胶（聚合物）的仿生足垫的湿吸附力进行测试,由此验证足垫与壁面间的液体薄膜对吸附力的积极影 响．然后设计一种实验研究用的轮爪式仿生爬壁机器人,并对其进行静力学分析．最后对所设计的机器人进行爬壁 试验．结果表明,液体薄膜可以有效提高足垫吸附力,所研制的湿吸附机器人可吸附于约85度的壁面,可成功爬行 于坡度约65度的玻璃壁面,一定程度上验证了湿吸附机理爬壁机器人的可行性．     

The soft multi-legged robot inspired by octopus: climbing various columnar objects

In this paper, we develop a soft climbing robot made of silicone. Octopus-like behaviour is realized by a simple mechanism utilizing the dynamics of the soft body, and the robot can grasp various objects of unknown shape. In addition, by inching its truck, it can climb various columnar objects. Experiments, using pipes, long balloons, and natural trees, are conducted to evaluate the effectiveness of the proposed robot.     

Development of snake-like robot ACM-R8 with large and mono-tread wheel

One of the important advantages of an active wheeled snake-like robots is that it can access narrow spaces which are inaccessible to other types of robot (such as crawlers, walking robots), since snake-like robots have an elongated, narrow body. Additionally, in areas with rubble, snake-like robots can traverse rough terrain and large obstacles since its body can conform to the terrain’s contours. ‘ACM-R8’ is a new snake-like robot which can climb stairs and reach doorknobs in addition to the features explained above. To fulfill these functions, the design of this robot incorporates several key features: joints with parallel link mechanism, mono-tread wheels with internal structure, force sensors and ‘swing-grousers’ which were developed to improve step climbability. In this paper, the design and control methods are described. Experiments confirmed high mobility on stairs and steps, with the robot succeeding in overcoming a step height of 600 mm, despite the height of the robot being just 300 mm.     

Development of a stair-climbing mobile robot with legs and wheels

This paper deals with the development of a stair-climbing mobile robot with legs and wheels. The main technical issues in developing this type of robot are the stability and speed of the robot while climbing stairs. The robot has two wheels in the front of the body to support its weight when it moves on flat terrain, and it also has arms between the wheels to hook onto the tread of stairs. There are two pairs of legs in the rear of the body. Using not only the rorational torque of the arms and the wheels, but also the force of the legs, the robot goes up and down stairs. It measures the size of stairs when going up and down the first step, and therefore the measurement process does not cause this robot to lose any time. The computer which controls the motion of the robot needs no complicated calculations as other legged robots do. The mechanism of this robot and the control algorithm are described in this paper. This robot will be developed as a wheelchair with a stair climbing mechanism for disabled and elderly people in the near future. This work was presented, in part, at the International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1996     

一种机器人新型足—掌机构研究和设计

本研究提出了一种适合作为多足爬壁机器人腿的足－掌机构。采用这种足－掌机构的抓壁机器人不仅能够顺利实现地－壁过 渡行走，而且有可能适应其他形状的非平壁面。     

Optimal design of a stair-climbing mobile robot with flip mechanism

Stairs overcoming is a primary challenge for mobile robots moving in human environments, and the contradiction between the portability and the adaptability of stair climbing robot is not well resolved. In this paper, we present an optimal design of a flip-type mobile robot in order to improve the adaptability as well as stability while climbing stairs. The kinematic constraints on the flip mechanism are derived to prevent undesired interferences among stairs, wheels and main body during climbing stairs. The objective function is proposed according to the traction demand of the robot during stair-climbing motion for the first time and the value of the objective function is calculated though kinetic analysis. The Taguchi method is using as the optimization tool because of its simplicity and cost-effectiveness both in formulating an objective function and in satisfying multiple constraints simultaneously. The performance of the robot under the optimal parameters is verified through simulations and experiments.     

变形履带轮椅机器人的张紧力最优估计和越障能力分析

针对一种新型变形履带机构的轮椅机器人,提出了一种动态确定履带张紧力大小的最优估计算法． 相对于传统的恒定张紧力履带式移动机构,动态确定张紧力显著地降低了功率损耗． 考虑到张紧力的建模复杂性,文中采用模糊决策算法,将影响张紧力的主要因素输入模糊决策模块． 然后结合最小二乘法得到履带张紧力的最优估计算法． 鉴于轮椅机器人越障过程中移动速度较慢的特点, 结合张紧力最优估计算法结果对轮椅机器人上楼梯起始阶段进行了静力学建模． 仿真结果证明了利用张紧力估计算法的越障轮椅机构能够平稳爬楼梯, 同时也表明了动态张紧力算法大大降低了驱动功率损耗．     

Optimal Design of a New Wheeled Mobile Robot Based on a Kinetic Analysis of the Stair Climbing States

In this paper, we propose a new wheeled mobile robot (WMR) with a passive linkage-type locomotive mechanism that allows the WMR to adapt passively to rough terrain and climb up stairs, making it ideal for applications such as building inspection, building security, and military reconnaissance. A simple four-bar linkage mechanism and a limited pin joint are proposed after considering two design needs: adaptability and passivity. To improve the WMR’s ability to climb stairs, we divided the stair-climbing motion into several stages, taking into consideration the status of the points of contact between the driving wheels and the step. For each of the suggested stages, a kinetic analysis was accomplished and validated using the multi-body dynamic analysis software package ADAMS. The object functions are presented for the stages that influence the WMR’s ability to climb stairs. The optimization of the object functions is carried out using the multi-objective optimization method.     

基于姿态角的轮腿机器人驱动控制系统研究

在城市楼道环境中,尤其在面对楼梯等障碍时,五星形轮腿式机器人具有越障能力强、控制简单的优势。为防止机器人在攀爬楼梯时出现较大偏航倾斜,通过仿真软件ADAMS和Simulink中建立了五星形轮腿式机器人的整车动力学模型和PID速度控制模型。结果表明,该联合仿真控制模型能有效、快速地控制机器人速度,减小偏航角度,降低了研究和开发成本。将该驱动控制系统移植到原机器人系统中,并分析了机器人在本控制系统控制下攀爬楼梯等特殊情况下的稳定性能。     

一种有效爬越楼梯的模块化可重组履带结构

针对楼宇内的移动监视和非结构化环境 ,研究了一种可重组的“履带—关节”机器人结构 ,通过模块化组合 ,它以很小的体积 (每个模块长 30cm ,宽 11.5cm ,高 11cm) ,获得了爬越楼梯的能力 .本文分析了履带机构爬越楼梯的原理 ,并实验论证了各种组合结构的地形适应性和移动能力 .     

Contact angle estimation and composite locomotive strategy of a stair-climbing mobile platform

This paper presents a stair-climbing mobile platform built on the Rocker–Bogie mechanism which enables to effectively climb up/down various sizes of stairs in indoor environments without violating its mobile stability. First, the link parameters of Rocker–Bogie mechanism are optimally chosen via the Taguchi method in order to make the trajectory of its center of mass (CM) as smooth as possible, which implies high mobile stability as well as excellent adaptability during climbing up/down stairs. Based on this optimization result, the proposed mobile platform is compactly and lightly constructed suitable for indoor applications by placing all motors and sensors inside the hollow links in order to prevent undesired interferences with stairs as well as to protect themselves from external impact. A simple, robust and cost-effective estimation algorithm is proposed to detect the contact angles between wheels and a stair with high fidelity. Through the kinematic and kinetic analysis combined with the wheel-stair contact angle information, a composite locomotive strategy is established not only to minimize the slip during climbing up a stair but also to prevent falling down during climbing down a stair. The extensive experiments against various types of stairs successfully demonstrate the capability of the proposed mobile platform to effectively and safely climb up/down stairs.     

基于ROS的蛇形机器人基本仿生运动与自主爬台阶控制

设计了一种带正交关节和主动轮组合的蛇形机器人。该机器人不仅能够实现基本的蜿蜒运动、纵向行波运动、横向翻滚运动和横向行波运动,且针对台阶式障碍物提出了一种自主爬越台阶的控制策略。机器人通过激光测距传感器与头部关节的仰角得到台阶高度,抬起相应高度的关节将头关节搭在台阶上,控制主动轮的推进速度与关节抬起的角速度相结合的方式达到上台阶的目的,并且在运动过程中将头部俯仰关节舵机的负载反馈作为判别下台阶的条件。基于ROS （robot operating system）构建了蛇形机器人仿真模型,并通过仿真与实验验证了机器人的基本运动控制和自主爬台阶控制策略的有效性。     

模块化可重构履带式微小型机器人的研究

研制了一种模块化可重构履带式微小型机器人．单个微小型机器人可以独立运行,多个微小型机器人可以重构成链形机器人和环形机器人．微小型机器人结构紧凑、体积小、重量轻．采用了微控制器和PC机两级控制体系,两级间采用蓝牙通讯．实验结果验证链形机器人具有较强的越障能力,能爬越楼梯;环形机器人具有高速及路面适应能力强的特点．     

Stair-climbing wheelchair with lever propulsion control of rotary legs

This paper describes a novel stair-climbing wheelchair operated by human upper body using lever propelled rotary-legs with posture transition mechanism. The design principle of this wheelchair is to make use of the user's latent upper body capability, with appropriate mechanisms to enable extended functionality of the regular wheelchair without the need of heavy, expensive mechanisms or electric motors. An arm-operated mechanism allows the user to overcome steps and stairs independently without any external power source. The developed wheelchair consists of manual wheels with casters for planar locomotion, which provides capabilities equivalent to a regular manual wheelchair. In addition, the wheelchair has a rotary-legs mechanism based on lever propulsion control for climbing stairs. It also has a passive mechanism powered by gas springs for posture transition to shift the user's center of gravity between two positions for planar locomotion and for stair-climbing. The proposed design consists of only passive components, which makes the wheelchair more compact and lightweight. In this paper we describe in detail the development of this wheelchair and an investigation of how users can climb stairs independently. We also present evaluation experiments with a healthy participant and a dummy to investigate the feasibility of the proposed design.