terminologi robot dan sistem kawalan robot

TERMINOLOGI ROBOT DAN SISTEM KAWALAN ROBOT

PRESENTED BY :

Suffian Bin Ayob

TUJUAN PEMBELAJARAN:

• Menerangkan tentang terminologi dan definasi yang di gunakan dalam sistem automasi dan robot.

• Menerangkan tentang sistem kawalan robot industri.

Kandungan

• Definasi Robot• Terminologi robot• Ketepatan• Pengelolaan• Gerakan antara muka• Liputan Kerja• Darjah Kebebasan• Peralihan

Kandungan

• Persendian

• Penghalaan

• Tatarajah

• Kebolehulangan

• Titik tengah mata alat

• Koordinat sel kerja

• Kelajuan

Kandungan

• Beban maksimum

• Pengolah

• Penggerak

• Pengesan hujung

• Off-Line Programming

• On-Line Programming

DEFINISI ROBOT YANG DIBERIKAN OLEH PERSATUAN ROBOT BRITISH

• Robot perindustrian adalah sebuah peranti atau alat pelbagai fungsi yang boleh diprogramkan berulang-ulangkali. (re-programmable)

• Ia direkabentuk untuk menggerakkan serta mengolah bahagian-bahagian, alat-alat atau alat khusus dalam kerja-kerja pembuatan melalui pergerakan yang boleh diubah-ubah untuk melakukan tugas-tugas di dalam proses pembuatan.(multi-functional manipulator)

TERMINOLOGI ASAS DALAM SISTEM AUTOMASI

1. Ketepatan

• Darjah kemampuan yang boleh dibuat oleh lengan robot untuk digerakkan ke satu titik tertentu dalam sel kerja apabila kita memasukkan koordinat-koordinat daripada stesen pemprograman di luar talian (off-line programming).

1(a).Accuracy:

• How close does the robot get to the desired point?

• When the robot's program instruct the robot to move to a specified point, it does not actually perform as per specified.

• The accuracy measure such variance. That is, the distance between the specified position that a robot is trying to achieve (programming point), and the actual X, Y and Z resultant position of the robot end effector.

1(b)Accuracy

• How closely a robot can reach a commanded position.

• Accuracy can vary with speed and position within the working envelope and with payload.

1(d) Accuracy

• The degree to which actual position corresponds to desired or commanded position; the degree of freedom from error.

• Accuracy involves the capability to hit a mark, or reach the point in space, or get the correct answer

• Accuracy of a robot is determined by three elements of the system: the resolution of the control system, the inaccuracies or imprecision of the mechanical linkages and gears and beam deflections under different load conditions, and the minimum error that must be tolerated to operate the arm under closed servo loop operation.

• Accuracy refers to the degree of closeness to a "correct" value;

2. Pengelolaan

• Pergerakan yang dilakukan oleh tangan robot untuk membawa objek melalui satu ruang (jarak) dari satu tempat ke tempat yang lain.

3. Gerakan antaramuka (Interface)

• Penggunaan komponen-komponen perkakasan untuk menyambung dua alat atau sebahagian dari storan atau pendaftar supaya boleh digunakan oleh dua atau lebih aturcara (program).

3(a)Interface (in Robotics)

• Those connections of one system that are matched to another system that is distinctly different because of the basic nature of each system.

• This may be due to the origin of design and construction or due to the basic objectives of each system independently.

• A shared boundary between system elements defined by common physical or logical interconnection characteristics, signal characteristics, and meanings of interchanged signals.

• A boundary between the robot and machines, transfer lines, or parts outside of its immediate environment.

4. Liputan kerja (work envelope)

• Isipadu/luas kawasan di mana lengan robot boleh melakukan tugasnya/kerjanya.

4(a)Work Envelope• The set of points that represents the maximum extent

and reach of a robot's wrist. • It excludes the end effector because manufacturers

cannot predict the shape or size of end-effector eventually used by the robot.

• The envelope can be rectangular, cylindrical, spherical or irregular.

• Shapes are determined by the length of the robot's links and the arrangement of the joints.

• Any envelope has three parameters associated with it: the horizontal arm sweep or the degrees of rotation about the center, the vertical motion of the arm, and the radial extension of the arm as measured from the center axis.

4(b)ENVELOPE Describe as the region of space a robot can reach.

• Envelope: A three-dimensional shape that defines the boundaries that the robot manipulator can reach; also known as reach envelope.

• Maximum envelope: the envelope that encompasses the maximum designed movements of all robot parts, including the end effector, workpiece and attachments.

• Restricted envelope is that portion of the maximum envelope which a robot is restricted by limiting devices.

• Operating envelope: the restricted envelope that is used by the robot while performing its programmed motions.

4(c)Work Envelope

• The area in which a robot can work, the limits to its motions.

5. Darjah -Kebebasan (D.O.F)

• Bilangan pergerakan hakiki dan tahap kompleksnya tugas yang boleh dilakukan oleh sebuah robot ditentukan oleh darjah kebebasan yang ada pada sesuatu robot.

• Pada amnya robot mempunyai tiga darjah kebebasan utama iaitu paksi x,y dan z.

• Robot-robot yang lebih canggih mempunyai paksi gerakan yang lebih banyak.

5(a)Degree of Freedom (DOF)

• Robot arms are often categorized by their degrees of freedom (DOF), which refers to the number of single axis joints in the robotic arm.

• The more axis joints in the industrial robotic arm, the higher degree of freedom and the more flexibility the robot has to perform precise movements with fast cycle times and higher throughput.

5(b)Degree of Freedom (DOF) • Each joint or axis on the robot introduces a

degree of freedom. • Each DOF can be a slider, rotary, or other type

of actuator. • The number of DOF that a manipulator

possesses thus is the number of independent ways in which a robot arm can move.

• An industrial robot typically have 5 or 6 degrees of freedom. 3 of the degrees of freedom allow positioning in 3D space (X, Y, Z), while the other 2 or 3 are used for orientation of the end effector (yaw, pitch and roll).

Joint Types Example

Prismatic or slider joints Revolute or rotary joints

6. Peralihan

• Pergerakan robot melalui satu garis lurus yang melibatkan pengawalan lebih dari satu paksi.

6(a)Motion control

• for some applications, such as simple pick-and-place assembly, the robot need merely return repeatably to a limited number of pre-taught positions.

• For more sophisticated applications, such as arc welding and spray painting, motion must be continuously controlled to follow a path in space, with controlled orientation and velocity.

7. Persendian (Joint)

• Sendi atau paksi yang terdapat pada pengolah (lengan robot).

• Terdiri dari dua jenis axis (paksi) iaitu ‘major axis’ yang terdiri dari ‘base’, ‘shoulder’ dan ‘elbow’ serta ‘minor axis’ yang terdiri dari ‘ wrist pitch’, ‘wrist roll’ dan ‘wrist yaw’.

5. D.O.F Industrial Robots

8. Penghalaan

• Pergerakan ‘end effector’ robot ataupun ‘minor axis’ untuk pergi ke tempat yang di arahkan.

9. Tatarajah

• Rekabentuk robot mengikut pandangan geometrinya contohnya kartesian, selinder, polar dan lengan bersambung (jointed arm).

9(a)Robotic Classification

• A means of identifying the types of robots. It can be based on physical characteristics such as hardware construction, degrees of freedom, coordinate systems, and level of sophistication and technology.

10. Keboleh- Ulangan (Repeatability) • Darjah kemampuan lengan robot untuk

mengesan sasaran yang telah disetkan dengan tepat dan kemudian kembali semula ke titik asalnya dalam sel kerja itu.

• Robot yang mempunyai kebolehulangan yang tinggi akan mampu mengulangi semula tugas itu dengan tepat berulang-ulang kali tanpa ralat.

10(a)Repeatability

• The ability of a robot to return repeatedly to a given position.

• It is the ability of a robotic system or mechanism to repeat the same motion or achieve the same position.

• Repeatablity is is a measure of the error or variability when repeatedly reaching for a single position.

• Repeatability is often smaller than accuracy.

10(b)Repeatability

• how well the robot will return to a programmed position.

• This is not the same as accuracy. • It may be that when told to go to a certain X-Y-Z

position that it gets only to within 1 mm of that position.

• This would be its accuracy which may be improved by calibration.

• But if that position is taught into controller memory and each time it is sent there it returns to within 0.1 mm of the taught position then the repeatability will be within 0.1 mm.

11. Titik tengah matalat (TCP)

• Ia adalah titik tindakan untuk matalat yang dipasang pada pelit matalat robot.

• Titik tengah matalat ialah titik rujukan pada matalat yang dikawal oleh robot.

11(a). Titik tengah matalat (TCP)

TCP

12. Koordinat-koordinat sel kerja

• Titik-titik yang diprogramkan dalam sel kerja dikenalpasti kedudukannya dengan menggunakan nilai-nilai koordinat-koordinat x, y dan z bagi titik tengah matalat serta sudut-sudut penyambungan paksi pada pergelangan lengan robot iaitu ‘pitch’,’roll’ dan ‘yaw’.

13. Kelajuan (Speed)

• Kadar pergerakan titik-tengah matalat yang dilakukan oleh robot di bawah kawalan program.

• Ia adalah ukuran kelajuan alat tersebut.

13(a)Speed

• how fast the robot can position the end of its arm.

• This may be defined in terms of the angular or linear speed of each axis or as a compound speed i.e. the speed of the end of the arm when all axes are moving.

13(b)Maximum Speed:

• A robot moving at full extension with all joints moving simultaneously in complimentary directions at full speed. The maximum speed is the theoretical values which does not consider under loading condition..

14. Beban maksimum (Payload)

• Beban maksima yang boleh digerakkan/dipindahkan oleh robot semasa di bawah kawalan program.

• Ia meliputi berat pencengkam dan produk/komponen yang diangkat.

• Semasa menggangkat beban ini lengan robot masih lagi dapat mengekalkan spesifikasi kebolehulangan dan keboleharapannya.

14(a)Payload

• The maximum payload is the amount of weight carried by the robot manipulator at reduced speed while maintaining rated precision.

• Nominal payload is measured at maximum speed while maintaining rated preci-sion. These ratings are highly dependent on the size and shape of the payload due to variation in inertia.

14(b)Payload

• The maximum total mass or weight that can be applied to the end of the robot arm without sacrifice of any of the applicable published specifications of the robot.

• Also referred to as Load Capacity.

15. Pengolah (Manipulator) • Bahagian mekanikal sistem robot yang boleh digerakkan

ke pelbagai arah, hasil dari gabungan pergerakaan paksi-paksi.

• Ia terdiri dari komponen-komponen seperi lengan manusia iaitu lengan atas dan lengan bawah yang disambung dengan ‘base’, ‘shoulder’, ‘elbow’ dan ‘wrist’.

• Ia dapat membawa alat pengesan hujung (end effector) ke destinasi-destinasi yang diperlukan.

• Selain dari komponen-komponen di atas, ia juga terdiri dari bahagian-bahagian seperti alas, pemacu penggerak, peranti suapbalik dan struktur penyokong untuk memegang serta menggabungkan semula alat-alat tersebut.

15(a)Manipulator

• A machine, the mechanism of which usually consists of a series of segments, jointed or sliding, relative to one another, for the purpose of grasping and/or moving objects usually in several degrees of freedom.

• It may be controlled by an operator, a programmable electronic controller, or any logic system.

16. Penggerak (Actuator) • Mekanisma yang digunakan untuk memacu

pengolah bagi membolehkannya bergerak ke titik yang telah ditentukan. Ia terdiri daripada komponen-komponen seperti selinder pneumatik atau hidraulik, motor-motor berputar pneumatik atau hidraulik dan motor-motor elektrik. Kedudukan robot juga ditentukan dengan gabungan komponen-komponen ini. Robot-robot yang mempunyai sistem penggerak yang mudah digerakkan secara mekanikal dengan menggunakan sesondol (cam).

16(a)Actuator

• A power mechanism used to effect motion of the robot; a device that converts electrical, hydraulic, or pneumatic energy into robot motion. (Common Misspellings: actuater, actuattor)

17. Pengesan hujung ( End- effector) • Perkakasan yang dipasang pada plet

hujung lengan pengolah yang berfungsi mengikut tugas yang akan dilakukan.

• Ia terdiri dari dua bentuk utama iaitu pencengkam (gripper) atau perkakasan ( tools).

17(a) End Effector

• A device specifically designed for attachment to the mechanical interface to enable the robot to perform its task.

17(b) End Effector

• The robot's last link. • The robot uses the end-effector to accomplish a task. • The end-effector may be holding a tool, or the end-

effector itself may be a tool. • The end-effector is loosely comparable to a human's

hand. • Examples may include gripper, spot-weld guns, arc-

weld guns, spray - paint guns, or any other application tools.

• (Common Misspellings: end-effecter, end-affector, end-affecter)

18) Off-Line Programming (Pengaturcaraan luar talian)• The programming of robotic controllers

and computers that involves the writing of task programs, the running of simulations, and the collection and organization of data either away from the robot or when it is not in operation.

19) On-Line Programming (Pengaturcaraan dalam talian)

• Robotic programming that makes use of the manipulator.

• It utilizes the actual robot in order to develop procedures and define the values of data items in a task program.

• One example of this kind of programming is the record-playback method, which is dependent on an actual robot for testing and demonstration.