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     

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.     

Development of a single-wheeled inverted pendulum robot capable of climbing stairs

ABSTRACT

In this paper, we propose the design of a single-wheeled robot capable of climbing stairs. The robot is equipped with the proposed climbing mechanism, which enables it to climb stairs. The mechanism has an extremely simple structure, comprised of a parallel arm, belt, harmonic drive, and pulley. The proposed climbing mechanism has the advantage of not requiring an additional actuator because it can be driven by using a single actuator that drives the wheel. The robot is equipped with a control moment gyroscope to control the stability in a lateral direction. Experimental results demonstrate that the robot can climb stairs with a riser height of 12–13?cm and a tread depth of 39?cm at an approximate rate of 2 to 3 s for each step.     

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...     

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。     

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。     

On Climbing Winding Stairs in an Open Mode for a New Robotic Wheelchair

This paper presents the mechanical design, locomotion and associated dynamic models of a new robotic wheelchair on climbing winding stairs. The prototype stair-climbing robotic wheelchair is constructed comprising a pair of rotational multi-limbed structures pivotally mounted on opposite sides of a support base so that the robotic wheelchair can ascend and descend stairs; in particular, the capability of climbing winding stairs is addressed. Based on the skid-steering analysis, the dynamic models for climbing winding stairs are developed for the trajectory planning and motion analyses. These models are required to ensure a passenger's safety in such a way that the robotic wheelchair is operated in an open mode. Moreover, an equivalent constraint method is proposed for the prescribed motion of the robotic wheelchair on climbing winding stairs. The results of the simulation and maneuver are reported that show the behavior of the prototype as it climbs winding stairs in a dynamic turning.     

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.     

Insectomorphic robot climbing a freely rolling ball

The problem of control of autonomous motion of a six-legged robot from a support horizontal plane to a ball that can freely move on this plane in an arbitrary direction is solved. Further robot motion aimed at acceleration or deceleration of the ball both in the direction of the longitudinal axis of its body and in the transverse direction ensuring dynamic stability of the robot on the ball is synthesized. Analytical conditions of implementability of the maneuver of climbing a ball are found. Formulas for estimating the maximum ball radius for which climbing of the robot is possible are obtained. Using the developed control algorithms, the robot can climb the ball and, staying on it, move the ball to the desired position in the plane. Robot motion is performed owing to the dry friction forces. Asymptotic stability of the programmed motion of the whole system is provided by a PD controller, which implements necessary step cycles of legs motion and the planned law of body motion. Results of 3D computer simulation of the controlled robot dynamics are discussed.     

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.     

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.     

Transition Motion from Ladder Climbing to Brachiation with Optimal Load-Allocation Control

Abstract

This paper describes the transition motion from ladder climbing to brachiation for a multi-locomotion robot (MLR). The MLR has versatile modes of locomotion, such as biped walking, quadruped walking, brachiation and ladder climbing. The transition is a challenging motion, because the environmental boundaries change and the robot has to switch the form of its locomotion depending on its surroundings, situations and purposes. The robot supports itself with three end-effectors that maintain its stability, while one hand transfers from a rung on the vertical ladder to a new rung behind the robot for brachiation. A closed kinematic chain is formed by the robot links and the ladder. In this case, if the number of position-controlled active joints is greater than the number of the chain’s degrees of freedom, an internal stress appears because of unavoidable position errors. The huge internal stress may lead some motors to become overloaded. Since the safety of each motor is very important for a serial-link robot, a load-allocation algorithm is proposed to balance the loads of the joint motors. The algorithm is verified through experiments.     

Design and analysis of a wall-climbing robot for passive adaptive movement on variable-curvature metal facades

To facilitate the safe adsorption and stable motion of robots on curved metal surfaces, a wall-climbing robot with a wheeled-type mobile mechanism that can passively self-adapt to walls with different curvature is proposed. The robot is composed of two relatively independent passive adaptive mobile mechanisms and overrunning permanent magnetic adsorption devices to achieve effective fitting of the driving wheels to the wall surface and adaptive surface motion. The overall design is based on a double-hinged connection scheme and gap-type permanent magnetic adsorption. The minimum adsorption force required for the robot to achieve stable climbing motion with no risk of slipping or capsizing is determined by developing a static analysis model. The effects of air-gap size and wall thickness on the adsorption force are analyzed by means of magnetic circuit design studies and parametric simulations on the permanent magnet adsorption device, as well as design optimization of the permanent magnet device. The motion performance test of the fabricated prototype shows that the robot can achieve adaptive curvature motion with self-attitude adjustment, and has a certain load capacity, obstacle crossing capability, and good surface adaptivity.     

An insectomorphic robot climbing over a freely rolling ball

An algorithm for the control of an insectomorphic robot climbing over a ball that rolls freely on a horizontal plane is developed and tested using computer simulation. The proposed motion involves three maneuvers. First, the robot climbs the ball at rest from the horizontal surface. At the end of this maneuver, the ball gains an angular velocity due to errors in the execution of the programmed motion. The further motion of the robot is designed so as to reduce the velocity gained in the course of climbing to an acceptable level. The motion is completed by the maneuver of getting down to the supporting horizontal plane from the almost motionless ball. The robot motion is implemented using the Coulomb friction without any special devices. The asymptotic stability of the programmed motion of the system as a whole is ensured by a PD controller that implements the step cycles of the leg motions and the planned motion of the body. Results of 3D computer simulation of the robot motion are discussed. The model of the mechanical robot-ball system is formed using the Universal Mechanism program package; this model is described by an automatically derived system of differential equations that take into account the dynamics of all solid elements.     

具有多种运动方式的小型模块化双手爪机器人MiniBibot

受尺蠖等动物攀爬动作的启发,开发了一款舵机驱动的具有多种运动方式的小型双手爪机器人MiniBibot.采用模块化方法设计和搭建了机器人系统,以攀爬杆件为控制实例介绍了用户程序开发的步骤和方法.然后根据该机器人的构型,提出了5种可实现的运动方式,并分析了各自的特点和应用.最后通过一系列实验,充分展示和验证了所提出的双手爪机器人系统及其运动方式的有效性和可行性.     

A control for an insectomorphic robot in climbing to the top of a vertical corner and in moving on a step ladder

For a six-legged robot, the problem of climbing a roof of a vertical right dihedral corner along its walls and a vertical high shelf with the help of a step ladder is investigated. The motions are realized with the help of the dry friction forces. The motion of the robot is formed by imposing servo-constraints in the form of adaptive step cycles of legs and the required geometric structure of body motion. An asymptotically stable program motion of legs relative to the body and the whole system is implemented by a PD controller. The results of 3D computer simulation of the controlled robot dynamics are presented.     

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.     

Whole-body motion planning and control of a quadruped robot for challenging terrain

Quadruped robots working in jungles, mountains or factories should be able to move through challenging scenarios. In this paper, we present a control framework for quadruped robots walking over rough terrain. The planner plans the trajectory of the robot's center of gravity by using the normalized energy stability criterion, which ensures that the robot is in the most stable state. A contact detection algorithm based on the probabilistic contact model is presented, which implements event-based state switching of the quadruped robot legs. And an on-line detection of contact force based on generalized momentum is also showed, which improves the accuracy of proprioceptive force estimation. A controller combining whole body control and virtual model control is proposed to achieve precise trajectory tracking and active compliance with environment interaction. Without any knowledge of the environment, the experiments of the quadruped robot SDUQuad-144 climbs over significant obstacles such as 38 cm high steps and 22.5 cm high stairs are designed to verify the feasibility of the proposed method.     

基于DSP技术的爬壁机器人吸附控制系统设计

壁面吸附是爬壁机器人的基本功能之一,其吸附程度直接影响爬壁机器人的稳定性和移动速度;为此,设计了基于DSP技术的爬壁机器人吸附控制系统;选择爬壁机器人传感器装置,加设DSP数字信号处理器,设计爬壁机器人吸附控制器;在硬件结构的支持下,根据爬壁机器人的组成结构和工作原理,构建相应的数学模型;在该模型下,利用DSP技术计算爬壁机器人吸附力;通过爬壁机器人在壁面环境下的受力分析结果,确定爬壁机器人安全吸附条件;以吸附控制器作为执行机构,实现爬壁机器人的吸附控制;选择负压爬壁机器人作为测试样机,通过系统测试表明,在瓷砖、木板、玻璃三种壁面环境下,与两个对比系统相比,应用此次设计系统得出爬壁机器人吸附力的控制误差降低了2.04 N,倾覆风险系数降低了0.29,具有较好的吸附控制效果。