Mechatronics Engineering Course Introduction Prof. Tianmiao Wang Prof. Li Wen School of Mechanical Engineering and Automation Beihang University 6/10/201
Professor biography Li Wen, Associate professor He worked as a Posdoc fellow at Harvard University, USA before joining Beihang University. He has served as the Session Chair for several academic conferences, including the IEEE/RSJ International Conference on Intelligent Robots and Systems and IEEE International Conference on Robotics and Automation. He was also the recipient of several domestic and international awards. Research interests: bio-inspired robotics, soft robotics, 3D printing and micro fabrication, bio-fluid mechanics. 6/10/201
Mechatronics System Design Very important!
Aim and questions 1. Why we study this course? (for the student) 2. How to learn this course better? 3. How to conduct the overall design of the mechatronic systems? 4. How we can build a mechatronics system step by step? 5. How to develop a proposal and the research plan of a project?
Overview 1 Design methods and criteria 2 Work Flow Mechatronics System 3 Examples 4 Project proposal and plan
Overall Design of a Mechatronics System Overall principal: Integrate the mechanical and electronics technology to design an integrated, optimal mechatronics system. Biomimetic dragon fly video Li Wen et al, 2010
Overall contents 1. Requirement analysis (purpose, function, financial cost, time cost) 2. Component selection (actuators, sensors, electronics etc.) 3. Detailed design (mechanical structure, kinematics and dynamic analysis)
1. Mechatronics System Design Method 1. Simplify whole Mechatronics system and select components:
Mechatronics System Design Method 2. Integrating: The constituent elements combine into different morphologies and functions.
Mechatronics System Design Method A more special case: Dimensions: L W H 500 150 100 Weight: less than 4kg Speed : 1m/s Power consumption: less than 20w Battery life: 1 hour Structure: Carbon fiber and wheel damping Modular robots in complex terrain
Modular robotic arm Composed of modular manipulator Rotating module Control circuit Sensors Robotic hand
Modular robotic arm Machine manufacturing video
Integrated mechatronics system examples Rehabilitation Service Robot Monitoring Industrial robots Service robots for entertainment
2. Mechatronics component selection
Example 1
Component selection - the overall structure 1. Overall structure Electromechanical complementary design principles, greatly simplifies the mechanical structure and function Their body composition include: power source, driving mechanism, guide support, frame sections Mechanical system consists of control functions of the flywheel, cam, Ratchet, Geneva mechanism and other agencies Note: initially design a variety of programs, comprehensive social security than the pros and cons, choose optimal
Component selection - The overall structure 1. Overall structure (Function: to achieve the level of the table between the pen and the relative motion in the X, Y direction.) Program 1:XY platform motion, fixed (only lift, fall); Program 2: XY platform does not move, the direction of movement of the pen to achieve XY Program 3:XY platforms and pen movement in XY directions (relatively complex, discard)
The structural schematic option 1
The structural schematic option 2
Schematics comparison Comparison of the options Program Structure Rigidity Overall comment Option 1 cross" shape Option 2 "T"-shaped Compact Better Complex Not compact Poor Relatively simple
Component selection - Motor 2. Motor selection Types DC servo motors Main features High response characteristics High power density Can achieve high-precision digital control Controller is simple Brushless DC servo motors Commutation parts have no contact Works with high-speed and high torque Good environmental resistance AC servo motor Stepper motor Good environmental resistance High-speed high torque working, solid structure Control angle is proportional to the number of pulses Can be controlled through a direct digital control Cheap
Motor parameters M M M M M M M M A load trans rot idle load trans rot idle load trans rot Load torque Transmis sional acceleration M No load torque M M M F F x a m a P J S Rotational acceleration tor que Fx P 2 1000 Fa P 2 1000 J S L nmax a 2 V 60 1000 mg Mass max Acceleration L Screw lengt h m a Screw lead Moment of inerti aof screw torque
Component selection - Sensors Selection of optical pulse generator for position measurement and to measure the speed of the motor.
Transmission systems Rotatorylinear Linear to Rotatory Rotatory-Swing Screw Slider-crank (piston) Slider-crank mechanism Gear-rack Cam
Typical transmission reducer: Harmonic reducer RV reducer Gear reducer
Typical transmission : Belt transmission Chain transmission
Program selection - Control Systems Control system selection Open-loop or closed loop PC + PMAC, microcontroller, embedded, industrial computer, PLC
Program selection - Control Systems AVR microprocessor based control
Program selection - Control Systems Alternative option: PC+Motion coordinator
Component selection - Control Systems
2D/3D simulation Solidworks
Our eventual work: XY planar workstation
Example 2
Scara robot Scara robot industrial application
Kinematics demonstration
Overview
Structural demostration Use kinematics simulation software, for example UG and Adams to analyze the structure property of the two DOF system.
D-H model and kinematic analysis using Matlab This teaching robot has 3 DOF, joint variable is θ1,θ2, θ3.
Plan selection Mechanical structure Mechanical components of mechatronic systems: -- Power source -- Transmission mechanism -- Guide support structure -- Rack section. M3 and screw 同步齿型带及带轮电机带动丝杠 机械手 manipulator Synchronous belt and pully Forearm 小臂谐波减速器 Harmonic reducer 大臂 Arm 谐波减速器 电机 电机 M2 M1 底座 Base
Calculation of the moment of inertia: Calculate the equivalent moment of inertia : Consider forearm as lever, which weights 1.2kg, 270 mm in length, Center of gravity: 52.5+300=352.5mm, Rotational inertia of forearm transited mlto 1 harmonic reducer 1 s output shaft 1.2 0.27 J ml 1.2 0.3525 0.156 kg. m 12 12 2 2 2 2 2
Consider arm as lever, which weights 1.4kg, 400 mm in length, Rotational inertia of forearm transited to harmonic reducer 1 s output shaft: J 2 1.4 0.4 3 2 0.075 kg. m harmonic reducer 2 and bearings considered concentrated mass, weighting 1.2kg, 300mm to shaft 1 in distance, moment of inertia: J3 1.2 0.3 0.108 kg. m 2 2 2
Motor 2, sleeve and bearing, harmonic reducer 1 are considered as cylinder, weighting 5kg 1 2 (Assuming these parts as a solid cylinder, m By dthe h 4 formula d, 0.052 we mcan figure out ) 1 1 J4 md 5 0.052 0.002 kg. m 8 8 2 2 2
A A D C B B C D 2 6 0 D 4 3 21 2 2 2 3 24 2 5 26 27 2 8 φ 17 H h 7 6 φ 26 H 7 h 6 61 80 3 2 件 20 φ 6 5 H 7 h 6 φ 2 1H 7 m 6 φ7 H h 7 6 19 φ 38.6 H 7 h 6 M 3X 8 6 件 18 φ 4 5 M h 7 6 φ 6 3 H 7 h 6 φ 50 H 7 h 6 17 φ 4 0 M h 7 6 3 62 03 2 件 φ 98 H h 7 6 φ 1 7H 7 m 6 D - - 16 φ 14 H 7 h 6 M 6X 16 6 件 M5 X1 6 6 件 A - - A 15 14 13 12 φ 98 H 7 h 6 φ 30 H m 7 6 φ 62 M h 7 6 3 62 06 2 件 φ 6 H k 7 6 φ6 H k 7 6 C - - C 56 9 φ 11 4 H h 7 6 φ4 H h 7 6 11 10 9 φ 50 H 7 h 6 φ 94 H 7 h 6 1 96 8 7 φ 13 2 H 7 h 6 6 2 9 5 T - - T B - - B 4 3 2 1 7 0 6 4 0 技术要求 : 1 ) 装配后要求两轴垂直基准面 A, 两臂摆动高度差小于 0. 0 5 m m 2 ) 两关节轴的轴承要求过盈装配, 过盈量 0. 0 0 5 m m 关节轴摆动小于 0. 0 1 m m 3 ) 两谐波减速器的安装要求同轴 通电测试后, 运动噪音要小而平稳 4 ) 关节轴的保险开关 ( 极限开关 ) 要求根据关节臂的极限位置配做开关位置 5 ) 同步齿型带的安装, 要求一定的预负荷, 保证第二关节的运动过程中同步带没有抖动 29 J X- 29 1 关节保险块 1 4 5 28 J X- -2 8 电机带轮 1 4 5 27 J X- 27 2 电机发兰 1 4 5 26 J X- 26 2 电机套 1 4 5 25 J X- 25 转动套 1 铸铁 24 J X- 24 同步带 1 橡胶 23 J X- 23 挡盖 1 L Y1 2C Z 22 J X- 22 大臂盖 1 L Y1 2C Z 21 J X- 21 带轮 1 4 5 20 J X- 20 大臂 1 L Y1 2C Z 19 J X- 19 带轮座 1 4 5 18 J X- 18 2 关节挡盖 1 A 3 17 J X- 17 2 关节盖 1 L Y1 2C Z 16 J X- 16 2 关节 1 L Y1 2C Z 15 J X- 15 2 轴座 1 4 0C r 14 J X- 14 2 关节轴 1 4 0C r 13 J X- 13 2 轴固定板 1 4 0C r 12 J X- 12 挡板 1 4 5 11 J X- 11 绕簧 1 钢丝 10 J X- 10 支柱 1 4 5 9 J X- 09 传感器挡片 1 A 3 8 J X- 08 一轴 1 4 0C r 7 J X- 07 锁母 1 4 5 6 J X- 06 一轴减速器发兰 1 4 0C r 5 J X- 05 一轴电机盖 1 4 5 4 J X- 04 底座盖 1 A 3 3 J X- 03 外壳 1 A 3 2 J X- 02 立柱 1 4 5 1 J X- 01 底座 1 铸铁 序号 代号 名 称 数量 材料 单件总计重量备注 标记处数分区更改文件号签名年 月 日设计 2 0 0 2 / 1 / 1 8 标准化 审 工 核 艺 批 准 装配图 阶段标记重量比例 共张第张 1 :1.5 北京航空航天大学机器人所 教学机器人 J X- 00
Robotic system design examples
Many thanks! Li Wen Email: liwen@buaa.edu.cn