Classifying Robots
Robots can be classified in various ways, depending on their components, configuration, and use. Three common methods of classifying robots are by the types of control system used, the type of actuator drive used, and the shape of the work envelope.
Type of Control System
Robots may use one of two control systems—non-servo and servo. The earliest type of robot was non-servo, which is considered a non-intelligent robot.
The second type is the servo robot. These robots are classified as either intelligent or highly intelligent. The primary difference between an intelligent and highly intelligent robot is the level of awareness of its environment.
Non-Servo Robots
Non-servo robots are the simplest robots and are often referred to as “limited sequence,” “pick-and-place,” or “fixed-stop robots.” The non-servo robot is an open-loop system. In an open-loop system, no feedback mechanism is used to compare programmed positions to actual positions.
Non-servo robots are also limited in their movement and these limitations are usually in the form of a mechanical stop (limit switch) which signals the controller when it is activated . This form of robot is excellent in repetitive tasks, such as material transfer.
Characteristics of non-servo robots:
• Relatively inexpensive compared to servo robots.
• Simple to understand and operate.
• Precise and reliable.
• Simple to maintain.
• Capable of fairly high speeds of operation.
• Small in size.
• Limited to relatively simple programs.
Servo Robots
The servo robot is a closed-loop system because it allows for feedback. In a closed-loop system, the feedback signal sent to the servo amplifier affects the output of the system. A servo amplifier translates signals from the controller into motor voltage and current signals. Servo amplifiers are used in motion control systems where precise control of position or velocity is necessary. In a sense, a servomechanism is a type of control system that detects and corrects for errors
Characteristics of servo robots:
• Relatively expensive to purchase, operate, and maintain.
• Use a sophisticated, closed-loop controller.
• Wide range of capabilities.
• Can transfer objects from one point to another, as well as along a controlled, continuous path.
• Respond to very sophisticated programming.
• Use a manipulator arm that can be programmed to avoid obstructions within the work envelope.
3. Oбразуйте существительные от глаголов
Lead (2), free, move, configure, apply, rotate, add, locate (2), orient, move (2) , compare, consider, classify (2), activate (2), repeat , achieve, sophisticate, obstruct, define
4. Прочитайте и скажите истинны или ложны следующие предложения.
1. Nowadays nearly all robots are programmed using the offline method. 2. Teach pendants are usually supplied by manufacturers. 3. The vertical traverse is movement on a vertical axis. 4. The end effector gets its flexibility from the wrist. 5. Mounting the robot on a track or moving base increases the robot’s reach. 6. The range of movement in each of robot’s joints is considerably greater in comparison with the human hand. 7. Non-servo robots are classified as either intelligent or highly intelligent. 8. Movement of servo robots is limited by mechanical stops. 9. Servo robots are excellent in repetitive tasks, such as material transfer. 10. As the servo robot allows for feedback it is a closed-loop system. 11. Servo amplifiers are used to provide precise control of position or velocity in motion control systems.
5. a) Прочитайте и переведите следующие слова
Physically, series, configuration, require , achieve, configuration, environment, mechanism, precise, voltage , characteristics
б) Определите какими частями речи эти слова являются.
6. Вставьте пропущеннные слова
Extend, actuator, closed-loop , motion, envelope, freedom, flexibility, traverse (2) , axis, sophisticated ,controller, pitch, degrees
The open loop hydraulic system has advantage of less heat generation and on the other hand the … circuit is preferred for better (precise) response of the actuation. 2. Scientists have created efficient artificial, or "robotic" muscles, which could carry a weight 80 times its own and able to… to five times its original length when carrying the load. 3. Engineers and scientists now can design … control systems. 4. There are several types of … used in robots. 5. Robot … planning encompasses several different disciplines, most notably robotics, computer science, control theory and mathematics. 6. This type of robot has six… of freedom, meaning it can pivot in six different ways. 7. Maximum … encompasses the maximum designed movements of all robot parts, including the end effector, workpiece and attachments. 8. Universal Robots’ robotic arms offer unparalleled performance in precision handling, … , and payload. 9. Playback control uses a … with memory to record motion sequences in a work cycle, as well as associated locations and other parameters, and then plays back the work cycle during programme execution. 10. The rotational… is movement on a vertical axis. 11. In order to completely define an objects location in space, at least six degrees of freedom must be defined; its Cartesian coordinates, or x, y, z location, and its orientation, or roll, … and yaw. 12. A robot with three movable joints will have three … and three degrees of…. 13. Range of motion is an important determinant of a robotic system’s capabilities and is usually measured by “degrees of freedom” (DOF), which refers to the number of axes a robot arm is able to … .
7. Соедините слова и их определения ( некоторым словам соответствует 2 определения)
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a) The movement of an aircraft or ship about its transverse axis
f) very complex or complicated
i) the relative disposition or arrangement of the parts or elements of a thing.
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8. Переведите следующие словосочетания :
а) in some degree, to some/a certain degree, academic degree, bachelor's degree, to award / confer a degree on, to take one's degree, master's degree, to freeze at zero degrees Celsius, degree of comparison
б) Составьте с ними предложения
9. Переведите следующие предложения
1. The letter arrived in a long envelope. 2. I can't tell you the exact amount, but my back-of-the-envelope calculation indicates a cost of about $300,000. 3. The simplest formal expression for an envelope of curves in the (x,y)-plane is the pair of equations. 4. To say that he bends the rules, pushes the envelope and extends the possibilities of fiction is to state only part of the case. 5. We're trying to push the envelope as much as possible.
10 . Вставьте пропущенные предлоги
for(2), along, according to, by(2), with (2), on
1. Stepper motors drive three linear actuators to provide motion … the x, y, and z axis. 2. If you want to calculate and/or optimize forces generated or required… a moving robot, this tutorial has the basics that you will need to understand. 3. This is achieved … designing a feedback system: rules that define how the algorithm should work. 4. In comparison … typical robotic leg design, this new leg offers reduced complexity. 5. The section of a control system that allows …feedback and self-correction and that adjusts its operation according to differences between the actual output and the desired output. 6. The way your robot gets its energy will depend …what your robot needs to do. 7. Pneumatic actuators may be classified …the type of movement. 8. Various types of robots are usually classified …their capabilities. 9. Compared… the hydraulic/pneumatic cylinder, the electric actuator has its unique features.
11. Выполните по вариантам письменный перевод текста
а) The manipulator of an industrial robot consists of a series of joints and links.
A robotic joint provides relative motion between two links of the robot. Each joint, or axis, provides a certain degree of freedom (dof) of motion. In most cases only one degree of freedom is associated with each joint; so a robot’s complexity can be classified according to the total number of degrees of freedom they possess.
б ) The work volume, or work envelope, is the three-dimensional space in which the robot can manipulate the end of its wrist. Work volume is determined by the number and types of joints in the manipulator, the ranges of the various joints, and the physical size of the links. Its actual shape is dependent on the robot’s configuration: a polar robotic сonfiguration tends to produce a spherical (or near - spherical) work volume; a cylindrical configuration has a cylindrical work envelope; and a Cartesian coordinate robot produces a rectangular work volume.
Переведите текст с русского языка на английский
Роботов обычно программируют операторы, передвигая руку в нужной последовательности либо путем воспроизведения этой последовательности с помощью устройства дистанционного управления. Некоторые сложные роботы могут программироваться непосредственно голосом, отдачей приказаний передвинуться на заданное расстояние и в заданном направлении. Новейшие образцы роботов оснащены сенсорной обратной связью и способны реагировать на происходящее в непосредственной близости от них. Для увеличения протяженности рабочего пространства, в котором может действовать рука, роботы устанавливают на направляющие или рамы и тем самым сообщают им ограниченную подвижность.
13. Прочитайте и перескажите текст.
Types of Industrial Robotic Configurations
http://www.thomasnet.com/articles/automation-electronics/industrial-robot-basics In terms of robotic movement capabilities, there are several common robotic configurations: vertically articulated, cartesian, SCARA, cylindrical, polar and delta.
Vertically Articulated
A vertically articulated configuration, also called jointed arm, involves connecting the jointed arm of a robot to the robot via a twisting joint. Because each link in the arm is connected by rotary joints, the robotic arm appears jointed.
Cartesian A cartesian configuration, also called rectilinear, can move along three axis (x, y and z); the work area is therefore square. The arm links in this configuration are connected via linear joints.