4. I. Pendahuluan (12)
• Manipulator (Robot Arm)
• Manipulator beberapa/untaian
JOINT LINK (rigid body) yang
LINK terhubung oleh JOINT
• Setiap link memiliki satu joint
• Pemberian gaya pada joint
menyebabkan link bergerak
• Degree of Freedom
(DOF) menyatakan
jumlah JOINT yang
dapat bebas digerakkan
5. I. Pendahuluan (13)
• Manipulation: The act of grasping and or moving
an object.
• Gripper: Attaches to a robot to allow an object to
be picked up
• End-Effector: Part of robot that affects the world.
This can be a gripper, a welding torch,
6. I. Pendahuluan (14)
• Repeatability: Perbedaan antara posisi aktual setelah robot
kembali ke posisi yang sama secara berulang.
Indikator yang menunjukkan seberapa baik robot dapat
kembali keposisi yang sama.
• Accuracy: Perbedaan antara posisi aktual dengan posisi
yang dihitung (desired position) dari model kinematik
Indikator yang menunjukkan seberapa baik robot dapat
bergerak menuju sebuah titik dalam ruang
• Precision: Ukuran kenaikan posisi yang terkecil. Desired
Position
• Resolution: Sensor Increment
Precision Accuracy
Actual
Ajacent
Position
Position
7. I. Pendahuluan (15)
• Tipikal : accuracy > repeatability > resolution
• Batas paling atas (upper limits) precision = resolution dan
Accuracy = 1/2 the precision.
• Hampir pada semua robot repeatability, accuracy dan
precision berubah tergantung pada work envelope
Type Hozizontal Vertical
Catesian Uniform Uniform
Cylindircal Decreases Radially Uniform
Spherical Decreases Radially Decreases Radially Desired
SCARA Varies Uniform Position
Articulated Varies Varies
Precision Accuracy
Actual
Ajacent
Position
Position
11. I. Pendahuluan (19)
• Aktuator/Penggerak Lengan Robot
Actuation Torque/Force Positional
Speed Control Type Cons
Type Density Repeatability
Good Linear Hydraulics
Hydraulics Very High Slow Poor Variable Valve
Some Rotation Leak, Control
2 position or Good Linear Life of Seals,
Pneumatics Medium Fast Limited
PWM Some Rotation Control
Good Linear
Electrical Low Fast Good Simple Power Density
Good Rotation
• Penggerak Motor Paling banyak digunakan
• Sistem Hidrolik biasanya digunakan pada robot las/welding atau
pengoperasaian bawah air.
• Sistem Pnematik digunakan pada gripper
12. I. Pendahuluan (20)
• Aktuator/Penggerak Lengan Robot
Power Fields Field Torque
Motor Type Commutation Thermal Amp Type Reliabilty Speed
Density Rotor Stator Ripple
DC Poor Windings 4
Brush DC Mechanical High Magnets Low Brushes Medium
Windings on Rotor Transistors
Brushless DC 6 3 Good Windings 6
Electrical Halls High Magnets Medium None High
Step Windings on Stator Transistors
Brushless DC 3 Good Windings 6
Sensor Based High Magnets Very Low None High
Sinusoidal Windings on Stator Transistors
Magnets N N
Stepper None Medium High Fair None Low
or Iron Windings Transistors
Medium 3 6
Reluctance Sensor Based Iron Low Fair None Medium
Low Windings Transistors
Medium 3 6
Inductance Sensor Based Induced Very Low Fair None Medium
Low Windings Transistors
13. I. Pendahuluan (21)
• Tipe Penggerak
• Direct Drive
• Geared
– Belts, Gears, Harmonic Drives, Cycloidal Cam
Direct Drive Gear Reduced
Backlash None Can be Significant
Power Density Poor Can be Very Good
Speed High Suficient for Most Applications
Friction/Stiction Low Can be High
Disturbances Seen Directly Divided by Gear Ration
Inetia Changes Seen Directly Divided by Gear Ration Squared
Process Feedback Fealt Directly Is Masked by Stiction in Geartrain
Noise Low Can be Loud
Reliability Very Good Good to Poor
P:ostion Sensor Coaxial Can Take Advantage of Gear Ratio
Weight Heavy Low
14. I. Pendahuluan (22)
4. TIPE ROBOT/JOINT
• Alasan Penggunaan Robot Industri
• Aplikasi Robot
Industri
