机械手运动及控制实验

4. Operational space
✓ Example1-Cylindrical-coordinate manipulators
r z
θ
manipulator
Two prismatic joints （z and r） One rotational joint （θ） for position determination
6. Experiment
6.2 操作步骤
（1）打开PC电源 （2）将控制箱后面板上的空气开关拨到ON位置 （3）将急停按钮依指示方向旋转一定角度 （4）启动绿色按钮 （5）进入机器人示教操作程序 （6）程序打开后，点击“打开控制器”——“伺服上电”
——“系统自检”——“自动回零”
6. Experiment
3. DOF (degree of freedom)
✓ Advantages
✓ Flexibility (灵活性) ✓ Capacity (能力)
✓ Disadvantages
✓ Heavy mass ✓ Sluggish control (控制迟缓)
✓ Several evaluation indices
Operation space
3 DOF
4. Operational space
✓ Example4-SCARA manipulators
θ2
Z
θ1
Fig.4-10
manipulator
One prismatic joints （Z）
Two rotational joint （ θ1， θ2 ）
for position determination
Vn V /(4L3 / 3)
(1)
V—— volume of operational space L——sum of the link lengths
5. End-Effector
➢ The end-effector can sometimes be called a robotic hand, but its mechanism is often completely different from that of a human hand.
3 DOF
Operation space
4. Operational space
✓ Example2-Polar-coordinate manipulators
r Ф
θ
manipulator
One prismatic joints （r） two rotational joint （Ф andθ） for position determination
3 DOF
Operation space
4. Operational space
✓ Example3-Articulated manipulators
θ3 θ2
θ1
manipulator
Three rotational joint （ θ1， θ2 ， θ3 ） for position determination
➢ Depending on different operations, end-effectors with fingers, suction pads, needles, spray nozzles, and cutters have been reported.
5. End-Effector
+：逆时针 向上
-：顺时针 向下
7. Homework （Report）
➢ What’s a manipulator? ➢Using the right joints to draw the GRB-400 manipulator. ➢Draw the operational space of the GRB-400 manipulator and calculate the Normalized volume index Vn ➢Design a manipulator with an end-effector, introduce its application and explain why you design it in this way.
6.2 操作步骤（续）
（7）对机器人进行操作，完成指定任务，并保存
作业要求：
a) 工件由P4点抓取后，搬运到P7点 后放置；
b) 再由P7点再搬运回P4点
（8）重放保存好的任务 （9）点击“自动回零” ——“伺服断点”——“关闭控制器” （10）操作完毕，退出机器人示教程序 （11）按急停按钮，再将空气开关拨到OFF位置 （12）退出Windows，关闭PC电源
➢ Thus the end-effector should not be designed for multipurpose use but for specific use, whereas the human hand, because of its flexibility, can carry out many different operations.
Experiment 1
Design and Control of Manipulators
1. What’s a manipulator?
A manipulator is defined as a device that has a function similar to that of a human arm and can move a work object in three dimensions.
5. End-Effector
Needle
5. End-Effector
spray nozzles
Baidu Nhomakorabea
5. End-Effector
Cutter
5. End-Effector
➢ The mechanism of the end-effector therefore depends on the object's properties and the operation.
6. Experiment
L3=170mm
L2=200mm L1=200mm
2=270º 1=270º
GRB-400 manipulator
6. Experiment
6.1 坐标空间
关节坐标空间
直角坐标空间
直接操作各个关节的运动 来完成机器人的运动
指定机器人末端执行器在直角坐标空 间中的运动来完成机器人操作任务
3 DOF
Operation space
4. Operational space
① Evaluation Operational space
• Operational space is one of the most important indices, because the robot cannot reach the work object if the position of the work object is not included in this space. As a rule of thumb, this space increases with total link length. When it is necessary to compare the different types of manipulators, the normalized volume index:
Finger
Support Tubes
Cable Pull
5. End-Effector
suction pad
Step 1: Hold the orange by the vacuum pad Step 2: Hold the orange into the hand cage Step 3: Cutting off the stem by cutters
Observer 1， 3:00 pm
Observer 2， 6:00 pm
Stress, force
B
A
C
Permanent displacement
O
displacement
Rotten part
Output layer
Ripness
Middle layer
Input layer
(Color) (Shape) (Size) (Sugar content)
The manipulator consists of joints and links.
Fig1 The mechanism of a manipulator
2. Symbols of joints
Prismatic joint
Rotational joint
Symbols of joints The mechanism of the manipulator can be drawn using joints and links