四足機(jī)器人環(huán)境感知、識(shí)別與領(lǐng)航員跟隨算法研究
發(fā)布時(shí)間：2018-07-23 18:52
【摘要】：腿足式機(jī)器人在運(yùn)動(dòng)中只需離散的落腳點(diǎn)而不需要連續(xù)的路徑,因此較輪式和履帶式機(jī)器人其能跨越更為復(fù)雜崎嶇的地形,具備更加優(yōu)異的運(yùn)動(dòng)靈活性和環(huán)境適應(yīng)性。按照機(jī)器人腿的數(shù)量可將腿足式機(jī)器人分為單足、雙足、四足、六足以及多足機(jī)器人。其中四足機(jī)器人是模仿四足動(dòng)物運(yùn)動(dòng)形式的一種機(jī)器人,它既有超于雙足機(jī)器人的平穩(wěn)性又避免了六足或多足機(jī)器人機(jī)構(gòu)的復(fù)雜性,既能以靜步態(tài)方式在復(fù)雜地形上緩慢行走又能以動(dòng)步態(tài)方式實(shí)現(xiàn)高速行走。因而在腿足式機(jī)器人研究領(lǐng)域,綜合其機(jī)構(gòu)復(fù)雜度和穩(wěn)定性,四足機(jī)器人是一種較優(yōu)的選擇方式。隨著對四足仿生機(jī)器人研究的逐步發(fā)展,研究重點(diǎn)已由四足機(jī)器人的結(jié)構(gòu)設(shè)計(jì)及運(yùn)動(dòng)穩(wěn)定性分析過渡到如何提高其在復(fù)雜環(huán)境下的適應(yīng)性,因而實(shí)現(xiàn)四足機(jī)器人對復(fù)雜環(huán)境的感知能力并提高其運(yùn)動(dòng)的自主性是當(dāng)前一個(gè)主流的研究方向。本論文對四足機(jī)器人在復(fù)雜條件下的環(huán)境感知系統(tǒng)構(gòu)建、地形識(shí)別、路徑規(guī)劃、領(lǐng)航員識(shí)別及跟隨等內(nèi)容進(jìn)行了全面而詳細(xì)的研究,主要內(nèi)容如下：1、構(gòu)建了三維激光掃描儀(或二維激光掃描儀+云臺(tái))+單目相機(jī)+TOF相機(jī)的四足機(jī)器人環(huán)境感知系統(tǒng)。該系統(tǒng)通過激光掃描儀與TOF相機(jī)共同獲取環(huán)境的深度信息,其中激光掃描儀可進(jìn)行大場景下較粗略的距離測量而TOF相機(jī)則可實(shí)現(xiàn)局部范圍內(nèi)較精細(xì)的地形信息獲取�；诘玫降沫h(huán)境深度信息,采用數(shù)字高程模型(DEM)進(jìn)行地形描述,并通過計(jì)算各柵格的坡度、粗糙度、起伏度對地形進(jìn)行識(shí)別.粗糙度由該柵格所處的坡度平面與其8鄰域高程點(diǎn)的離散程度進(jìn)行計(jì)算,避免了采用高程方差計(jì)算時(shí)對粗糙度的誤檢測。2、為了提高路徑重規(guī)劃的效率及機(jī)器人的安全性,該文對A*算法做了改進(jìn),并分別提出了增量式A*算法(IA*)、具有障礙物柵格擴(kuò)展功能的擴(kuò)展A*算法(EA*)及EA*算法的增量形式算法(IEA*)。IA*算法在初始時(shí)刻采用A*算法尋找一條最優(yōu)路徑,然后在其余時(shí)刻通過尋找當(dāng)前路徑與目標(biāo)投影點(diǎn)的最優(yōu)路徑進(jìn)行增量式路徑規(guī)劃。與A*算法相比IA*算法雖不能保證搜索到最短路徑,但它不需要從起點(diǎn)重新進(jìn)行路徑規(guī)劃,從而大大提高了規(guī)劃效率。EA*算法通過增大柵格g值的方式實(shí)現(xiàn)對障礙物的擴(kuò)展,這種方式可以使路徑在遠(yuǎn)離障礙物的同時(shí)不會(huì)阻塞狹窄通道。3、四足機(jī)器人對領(lǐng)航員的準(zhǔn)確識(shí)別是實(shí)現(xiàn)機(jī)器人領(lǐng)航員跟隨功能的前提,為保證識(shí)別的穩(wěn)定性,該文采用領(lǐng)航員佩戴特殊反光材料的方式實(shí)現(xiàn)其與環(huán)境特征的區(qū)分。四足機(jī)器人通過激光掃描獲得的反射光強(qiáng)度信息對該反光標(biāo)識(shí)進(jìn)行探測,進(jìn)而實(shí)現(xiàn)對領(lǐng)航員的識(shí)別與定位。同時(shí)通過坐標(biāo)映射則可實(shí)現(xiàn)激光掃描儀測得的領(lǐng)航員位置在圖像坐標(biāo)系下的投影,從而可進(jìn)一步采用圖像處理的方式對領(lǐng)航員位置做進(jìn)一步判斷。機(jī)器人與領(lǐng)航員之間的路徑通過IEA*算法進(jìn)行規(guī)劃。4、為了實(shí)現(xiàn)對四足機(jī)器人的運(yùn)動(dòng)控制,該文對四足機(jī)器人的運(yùn)動(dòng)學(xué)模型進(jìn)行分析,通過該模型可得出機(jī)器人足端坐標(biāo)與關(guān)節(jié)旋轉(zhuǎn)角度的關(guān)系,然后通過設(shè)計(jì)的四足機(jī)器人單腿液壓伺服控制器實(shí)現(xiàn)對機(jī)器人各關(guān)節(jié)作動(dòng)器的伺服控制,進(jìn)而實(shí)現(xiàn)了機(jī)器人的行走功能。四足機(jī)器人在路徑跟隨時(shí)的難點(diǎn)是控制其轉(zhuǎn)彎特性,因而該文同時(shí)對四足機(jī)器人的轉(zhuǎn)向運(yùn)動(dòng)進(jìn)行了分析,并通過調(diào)整運(yùn)動(dòng)控制策略實(shí)現(xiàn)了對路徑的跟隨。
[Abstract]:Leg foot robots only need discrete foothold in motion and do not need continuous paths. Therefore, the wheeled and tracked robots can span more complex rugged terrain and have more excellent flexibility and environmental adaptability. According to the number of robot legs, the leglegged robots can be divided into single foot, bipedal, quadruped, and six feet. The quadruped robot is a kind of robot which imitates the form of quadruped. It not only has the stability of the bipedal robot, but also avoids the complexity of the six foot or multi foot robot mechanism. It can walk slowly in the complex terrain in the static gait mode and can walk in the dynamic gait way. With the complexity and stability of the leg foot robot, the quadruped robot is a better choice. With the development of the research on the quadruped bionic robot, the focus of the research has been transferred from the structure design and the motion stability analysis to how to improve its adaptability in the complex environment. It is a mainstream research direction to realize the ability of the quadruped robot to perceive the complex environment and improve the autonomy of its movement. This paper makes a comprehensive and detailed study on the construction of the environment perception system, terrain recognition, path planning, navigator identification and following capacity in the complex conditions of quadruped robots. The main contents are as follows 1, 1, a four legged robot environment perception system is constructed with a three-dimensional laser scanner (or a two-dimensional laser scanner + cloud platform) and a single camera +TOF camera. The system uses a laser scanner and a TOF camera to obtain the depth information of the environment, in which the laser scanner can measure a rough distance in a large scene and the TOF camera can be realized. Based on the acquired depth information, a digital elevation model (DEM) is used to describe the terrain, and the terrain is identified by calculating the gradient, roughness and undulating degree of the grid. The roughness is calculated from the level of the gradient of the grid and its 8 neighborhood elevation points. In order to improve the efficiency of the path replanning and the security of the robot, the A* algorithm is improved in order to improve the efficiency of path replanning and the security of the robot. The incremental A* algorithm (IA*), the extended A* algorithm (EA*) with the barrier extension function and the incremental formal algorithm of EA* algorithm (IEA*).IA* algorithm are used in the.2. In the initial time, the A* algorithm is used to find an optimal path, and then the optimal path of the current path and the target projection point is searched for the incremental path planning at the rest of the time. Compared with the A* algorithm, the IA* algorithm can not guarantee the shortest path, but it does not need to rearrange the path planning from the starting point, thus greatly improving the planning efficiency. The rate.EA* algorithm can expand the barrier by increasing the grid g value. This way, the path can not block the narrow channel.3 while the path is far away from the obstacle. The accurate identification of the four legged robot to the pilot is the premise to realize the following function of the robot navigator. In order to ensure the stability of the identification, the passage is worn by the navigator. The special reflective material distinguishes it from the environmental characteristics. The reflective light intensity information obtained by the laser scanning is detected by the quadruped robot, and the identification and location of the navigator are realized. At the same time, the position of the navigator measured by the laser scanner can be realized in the image coordinate system by the coordinate mapping. The path between the robot and the navigator can be further judged by the way of image processing. The path between the robot and the navigator is planned by the IEA* algorithm. In order to control the motion of the quadruped robot, the kinematics model of the quadruped robot is analyzed. The model can be used to get the robot foot sitting. The relationship between the standard and the rotation angle of the joint, and then the servo control of the robot joint actuator by the designed single leg hydraulic servo controller of the quadruped robot, and then the walking function of the robot is realized. The difficulty of the four legged robots in the path and at any time is to control the turning characteristics, so the paper also transfers the four legged robots at the same time. The movement is analyzed, and the path following is achieved by adjusting the motion control strategy.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TP242
，
本文編號：2140333
[Abstract]:Leg foot robots only need discrete foothold in motion and do not need continuous paths. Therefore, the wheeled and tracked robots can span more complex rugged terrain and have more excellent flexibility and environmental adaptability. According to the number of robot legs, the leglegged robots can be divided into single foot, bipedal, quadruped, and six feet. The quadruped robot is a kind of robot which imitates the form of quadruped. It not only has the stability of the bipedal robot, but also avoids the complexity of the six foot or multi foot robot mechanism. It can walk slowly in the complex terrain in the static gait mode and can walk in the dynamic gait way. With the complexity and stability of the leg foot robot, the quadruped robot is a better choice. With the development of the research on the quadruped bionic robot, the focus of the research has been transferred from the structure design and the motion stability analysis to how to improve its adaptability in the complex environment. It is a mainstream research direction to realize the ability of the quadruped robot to perceive the complex environment and improve the autonomy of its movement. This paper makes a comprehensive and detailed study on the construction of the environment perception system, terrain recognition, path planning, navigator identification and following capacity in the complex conditions of quadruped robots. The main contents are as follows 1, 1, a four legged robot environment perception system is constructed with a three-dimensional laser scanner (or a two-dimensional laser scanner + cloud platform) and a single camera +TOF camera. The system uses a laser scanner and a TOF camera to obtain the depth information of the environment, in which the laser scanner can measure a rough distance in a large scene and the TOF camera can be realized. Based on the acquired depth information, a digital elevation model (DEM) is used to describe the terrain, and the terrain is identified by calculating the gradient, roughness and undulating degree of the grid. The roughness is calculated from the level of the gradient of the grid and its 8 neighborhood elevation points. In order to improve the efficiency of the path replanning and the security of the robot, the A* algorithm is improved in order to improve the efficiency of path replanning and the security of the robot. The incremental A* algorithm (IA*), the extended A* algorithm (EA*) with the barrier extension function and the incremental formal algorithm of EA* algorithm (IEA*).IA* algorithm are used in the.2. In the initial time, the A* algorithm is used to find an optimal path, and then the optimal path of the current path and the target projection point is searched for the incremental path planning at the rest of the time. Compared with the A* algorithm, the IA* algorithm can not guarantee the shortest path, but it does not need to rearrange the path planning from the starting point, thus greatly improving the planning efficiency. The rate.EA* algorithm can expand the barrier by increasing the grid g value. This way, the path can not block the narrow channel.3 while the path is far away from the obstacle. The accurate identification of the four legged robot to the pilot is the premise to realize the following function of the robot navigator. In order to ensure the stability of the identification, the passage is worn by the navigator. The special reflective material distinguishes it from the environmental characteristics. The reflective light intensity information obtained by the laser scanning is detected by the quadruped robot, and the identification and location of the navigator are realized. At the same time, the position of the navigator measured by the laser scanner can be realized in the image coordinate system by the coordinate mapping. The path between the robot and the navigator can be further judged by the way of image processing. The path between the robot and the navigator is planned by the IEA* algorithm. In order to control the motion of the quadruped robot, the kinematics model of the quadruped robot is analyzed. The model can be used to get the robot foot sitting. The relationship between the standard and the rotation angle of the joint, and then the servo control of the robot joint actuator by the designed single leg hydraulic servo controller of the quadruped robot, and then the walking function of the robot is realized. The difficulty of the four legged robots in the path and at any time is to control the turning characteristics, so the paper also transfers the four legged robots at the same time. The movement is analyzed, and the path following is achieved by adjusting the motion control strategy.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TP242
，
本文編號：2140333
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