Robotics 10 Quarter 3 Learning Activity Sheets (LAS) Module 2 PDF

10 Robotics 10 Quarter 3 Learning Activity Sheets (LAS) Module 2 Final Elements and Control Interface Writer: REY F. MIRAFLOR CRSHS Surigao City Division These Learning Activity Sheets (LAS) were...

10 Robotics 10 Quarter 3 Learning Activity Sheets (LAS) Module 2 Final Elements and Control Interface Writer: REY F. MIRAFLOR CRSHS Surigao City Division These Learning Activity Sheets (LAS) were designed and written with you in mind to help you master the Final Elements and Control Interface. The scope of this learning material focuses on the many different learning situations. Moreover, the language used recognizes the diverse vocabulary level of learners. The lessons are also arranged following the standard sequence of the course. Hence, the order in which you read them can be changed to correspond with the textbook you are now using. The LAS Module 2 contain: Lesson 1. Final Elements and Control Interface: Status, Indicator Devices, Actuator and Locomotion. After going through this LAS, you are expected to: a. discuss the principles and concepts of control interface, functions, status indicator devices, actuator and locomotion; b. integrate status indicator to control interface; and c. select appropriate control interfaces and actuators for a specific function or purpose. 2  Final Elements and Control Interface The word robot comes from the Czech word for forced labor, or serf. It was introduced by a playwright Karel Capek, whose fictional robotic inventions were created by chemical and biological, rather than mechanical, methods. Isaac Asimov’s Three (3) Robotic Laws are as follows (1942): 1. A robot may not injure a human being or, through inaction, allow a human being to come to harm. 2. A robot must obey the orders given it by human beings except where such orders would conflict with the First Law. 3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws. Basically a robot consists of:  A mechanical structure, such as a wheeled platform, arm, or other construction, capable of interacting with its environment.  Sensors to sense the environment and give useful feedback to the device.  Systems to process sensory input in the context of the current situation and instruct the device to perform actions in response to the situation. Mechanical Structure The robot structure consists basically of the robot body that includes arms and wheels. Some force such as electricity is required to make the arms and wheels turn under command. One of the most interesting aspects of robot in general is its shorturl.at/ruzBK shorturl.at/ruzBK behavior, which requires a form of intelligence. Motors A variety of electric motors provide power to robots, making them move with various programmed motions. The efficiency rating of a motor describes how much of the electricity consumed is converted to mechanical energy. DC motors. Permanent-magnet DC motors require only two leads, and use an arrangement of fixed- and electro-magnets (stator and rotor) and switches. These form a commutator to create motion through a spinning magnetic DC motors field. shorturl.at/rDM89 AC motors. These motors cycle the power at the input-leads, to continuously move the field. shorturl.at/qySTU AC motor Stepping motors. They are like a brushless DC or AC motor. They move the rotor by Stepper motors applying power to different magnets in the motor in sequence (stepped). Stepping motors are designed for fine control and will not only spin on command, but can spin at any number of steps-per-second (up to their maximum speed). Servomotors. Servos are simple shorturl.at/gwIPU DC motors with gearing and a feedback control system. They adjust themselves until they match the signal. Servos are used in shorturl.at/qtFJV radio control airplanes and cars. Servo motor Mechanisms Gears and chains. Gears and chains are mechanical parts that provide a mechanism to transmit rotational motion from one place to another with a possibly of changing it along the way. The speed change between two gears depends on shorturl.at/zFOQT the number of teeth on each gear. Pulleys and belts. Pulleys and belts, two other simple machines used in robots, work the same way as gears and chains. Pulleys are wheels with a groove around the edge, and belts are the rubber loops that fit in that groove. Gearboxes. A gearbox operates on the same principles as the gear and chain, shorturl.at/oEHV3 without the chain. Examples of gearboxes are found on the transmission in a car and the paper-feed of a printer. shorturl.at/fjpFN Sensors Robots operate according to a basic measurement, requiring different kinds of sensors. A sense of time is usually built-in through perceptual hardware and software, which updates quickly. Sensors interact with external environment and transforms the energy associated with what is being measured (sound, light, pressure, temperature, etc.) into another form of energy. Common sensors used in robotics include light sensors, touch sensors, shorturl.at/yJSXZ sound sensors, and acceleration sensor. A sound sensor is installed at the ear position of the robot in order to detect the voice of a subject. An acceleration sensor is installed in the body to detect shaking. A touch sensor is installed in the forehead of the robot to detect touch Power Supply In general, power supply is provided by two types of sources: batteries that are used once only and then discarded; and rechargeable batteries that operate from a reversible chemical reaction and can be recharged thousand times. The first use of a rechargeable battery gives up to 4 hours of continuous operation in an application. shorturl.at/cvDLT Control System There are two main systems to control robots: logic circuit and a microcontroller. Logic Circuit A digital logic circuit controls the mechanical system. The circuit is usually coupled to the mechanical structure through a bridge relay. A control signal generates a magnetic field in the relay's coil that mechanically closes a switch. transistors, for example, are good silicon switches, available in many technologies to control the mechanical systems. shorturl.at/mstNY Microcontroller Microcontrollers are intelligent electronic devices that are used inside robots. They deliver functions similar to those performed by a microprocessor (CPU) inside a personal computer. Microcontrollers are slower and have less memory than CPUs, but are designed for real-world control problems. One of the major differences between CPUs and microcontrollers is the number of shorturl.at/jHIP2 external components needed to operate them. Microcontrollers may run with no external parts, and typically need only an external crystal or oscillator. There are three main characteristics of a microcontroller for consideration: speed, size, and memory. Speed is designated in clock cycles, and is usually measured in millions of cycles per second (Megahertz, MHz). Size specifies the number of bits of information the Microcontroller can process in one step (for example, 4-, 8-, 16-, and 32-bits). Microcontrollers count most of their read-only memory (ROM) in thousands of bytes (kB) and random access memory (RAM) in single bytes. Status indicators Use status indicators to provide status information about key outputs in your model. Status indicators tell model users the status of the model simulation at a glance, by shorturl.at/deoAY displaying a color (green, yellow, or red) based on the parameters you define for the status indicator. You can configure a status indicator to display as a simple lamp, or as a speedometer gauge. In either case, the indicator will light up, using green, yellow, or a flashing red color to indicate the status of the key output. shorturl.at/deoAY When you add a status indicator to the Interface layer of your model, you define it by associating it with an entity in your model. Then you select if the status indicator will perform as a lamp or a speedometer gauge. Finally, you specify the entity values that will turn on the status indicator at each color level (green, yellow, and red). Actuators An actuator is a part of a device or machine that helps it to achieve physical movements by converting energy, often electrical, air, or hydraulic, into mechanical force. Simply put, it is the component in any machine that enables movement. Sometimes, to answer the question of what does an actuator do, the process is compared to the functioning of a human body. Like muscles in a body that enable energy to be converted to some form of motion like the movement of arms or legs, actuators work in a machine to perform a mechanical action. shorturl.at/mrHLV Actuators are present in almost every machine around us, from simple electronic access control systems, the vibrator on your mobile phone and household appliances to vehicles, industrial devices, and robots. Common examples of actuators include electric motors, stepper motors, jackscrews, electric muscular stimulators in robots, etc. Different types of Robot Actuators The robot actuators can classify based on how they move the output motor shaft and which energy they transform to make the move. According to the movement of the actuator shaft, we can simply classify the actuators as 1. Linear Actuators: The shaft of the linear actuators will only move in a linear fashion. 2. Rotary actuators: The shaft of the rotary actuator will only rotate in an axis. The linear and rotary actuators can be classified based on the energy they use to move the shaft of the motors. Here is a list of actuator classes that use different energy to create movement. 1.1 Hydraulic actuators The hydraulic actuators are used in robots handling heavy loads. These actuators can produce very high force if we compared them with other actuators. These actuators are deployed where higher speed, accuracy, and stability are required. These actuators have a cylinder and piston arrangement which is shown in the following figure. The chamber is filled with hydraulic fluid. The pressure applied to the fluid will push the piston, and that will move the actuator output shaft. The hydraulic actuators can convert the piston movement into linear and rotary movements. Example of hydraulic actuator and its cross section. Advantages of Hydraulic actuator 1. Easy to control and accurate A common example of a hydraulic actuator 2. Simpler and easier to maintain system: JCB 3. Constant torque or force regardless of speed changes 4. Easy to spot leakages of system 5. Less noise Disadvantages of Hydraulic actuator 1. Proper maintenance is required 2. Expensive 3. Leakage of the fluid creates environmental problems 4. Wrong hydraulic fluid for a system can damage the components Hydraulic actuators in JCB (marked as red) The Boston Dynamics WildCat robot is one of the example robot working with hydraulic actuators. https://www.youtube.com/watch?v=wE3 fmFTtP9g&t=128s Pneumatic actuators As you have seen in hydraulic actuators, they use a hydraulic fluid in the cylinder in order to move the piston. The pressure applied to the fluid will move the piston. But in pneumatic actuators, instead of hydraulic fluid, compressed air is moving the piston. Similar to hydraulic actuators, it can produce linear and rotary movements. When compared to hydraulic actuators, here are the advantages and disadvantages of Pneumatic actuators. Advantages of Pneumatic actuators 1. Clean, less pollution to the environment 2. Inexpensive 3. Safe and easy to operate Disadvantages of Pneumatic actuators 1. Loud and noisy 2. Lack of precision controls 3. Sensitive to vibrations Here is an example of a bionic soft arm robot that is made of Pneumatic actuators. The robot is made by a robotics company called Festo. BionicSoftArm: Modular pneumatic lightweight robot Here is the video of BionicSoftArm https://www.youtube.com /watch?v=JbGhtpSfPmU Electric actuators The commonly used actuators in robotics are electric actuators. This actuator converts electric energy into linear or rotary motion. The electric actuator can be AC/DC actuators. Mostly, robots are using DC actuators. Here are the advantages and disadvantage of electric actuators Advantages of electric actuators 1. These actuators offer the highest precision among other actuators. 2. It can be easily network and can easily program. They offer immediate feedback for diagnostic and maintenance. 3. They provide complete control on motion profiles and can include an encoder to control the velocity, position, and torque. 4. Less noise compared to hydraulic and pneumatic actuators 5. No fluid leak, so fewer environmental hazards. Disadvantages of electric actuators 1. The initial cost of the electrical actuator is higher 2. Unlike pneumatic and hydraulic actuators, these actuators are not suitable for all environments. 3. There are overheating, wear and tear issues are there compared to pneumatic and hydraulic actuators. 4. The actuator’s parameters are fixed, so to change torque, speed, etc to a different level, actuators should replace. Different types of DC actuators Let’s see different types of DC actuators used in robots. DC Motors: A dc motor will have ‘+’ and ‘-‘ negative terminal. The output of the dc motors shaft will start to spin if we supply DC voltage to the motor terminals. The speed of the motor shaft can be adjusted based on the voltage across the motor terminals. Here are some examples of DC motors that you can buy. DC Gear Motor: Adding a gearbox on DC motors can increase the shaft torque and reduce the motor speed. DC Gear motors consist of a DC motor attached with a gear system with an output shaft. Servo Motors: The servo motors consist of a DC motor plus gear system plus a servo control circuit. The servo control circuit can able to rotate the gear shaft with a specific angle. The computer inside the robot can command the servo motor to rotate at a specific angle using PWM signals. There are different types of servo motors, the normal servos are called RC (radio control) servos. There are analog servos and digital servos. Normal RC servos are analog servos. Here are some examples of RC servo motors Here is a video of the working principle of normal RC servo motor https://www.youtube.com/watch?v=LXURLvga8bQ&t=3s Stepper Motors: The stepper motors are DC motors that can move in discrete steps. This motor is having multiple sets of coils organized in groups called “phases“. The motor will rotate in each step at a time when you trigger each phase in a sequence. The stepper motors are used where high precision in movement is required. Here are a few examples of stepper motor you can purchase Here is a detailed working video of stepper motors. https://www.youtube.com/watch?v=eyqwLiowZiU BLDC Motors: BLDC motors are quite popular nowadays and used in many robotic applications. The BLDC motor stands for Brushless DC motor. The main difference between BLDC and DC motors is, ordinary DC motors work using a commutator, which is touching the brushes in the armature, but there is no commutator and brushes in BLDC. Instead of brushes, it uses an electronic commutation. Here are some examples of BLDC motors that you can purchase BLDC motors are using in robotics widely, here are some videos which are demonstrating its working. https://www.youtube.com/watch?v=YqmB6jlUfR0&t=300s Harmonic Drives: Harmonic drive, which is the brand name of strain wave gear trademarked by Harmonic Drive company and invented in 1957. It is very popular in robotics applications. The working of harmonic drives is demonstrated in the following video https://www.youtube.com/watch?v=7QidXf9pFYo Linear DC actuators: These dc motors can convert the DC voltage to linear motion just like pneumatic and hydraulic actuators you have already read. There is a lot of robotic application using linear actuators. Here are some videos to show the working of these motors. https://www.youtube.com/ watch?v=hi5B6goAPlU Activity 1. Matching Type. Direction: Match column A with the correct answer on column B, write only the letter of your answer on the blank provided at the right side of the test paper. Column A Column B ____1. Karel Capek a. requires only two leads, and use an arrangement of fixed- and electro-magnets (stator and rotor) and switches. ____2. robot b. interacts with external environment and transforms the energy ____3. DC Motor associated with what is being measured (sound, light, ____4. gears pressure, temperature, etc.) into another form of energy. ____5. sensor c. Robot was introduced by a playwright whose fictional robotic ____6. status indicator inventions were created by chemical and biological, rather than mechanical methods. ____7. Pneumatic ____8. digital logic d. provides status information about key outputs in your model. ____9. BLDC motor e. simple DC motors with gearing and a feedback control system. ____10. servo motor f. it comes from the Czech word for forced labor ____11. pulleys g. a part of a device or machine that helps it to achieve physical movements by converting energy, often electrical, air, or ____12. power supply hydraulic, into mechanical force ____13. stepper motor h. DC motors that can move in discrete steps ____14. actuators i. wheels with a groove around the edge, and belts are the rubber ____15. microcontroller loops that fit in that groove. j. it may run with no external parts, and typically need only an external crystal or oscillator. k. the heart of the circuit l. stands for Brushless DC motor m. use compressed air in moving the piston. n. the circuit that controls the mechanical system. o. mechanical parts that provide a mechanism to transmit rotational motion from one place to another with a possibly of changing it along the way. Directions: Complete the 3-2-1 Chart about your discoveries Final Elements and Control Interface. Write your answers on a separate sheet of paper. Answer Key Activity 1. Matching Type 1. c 6. d 11. i 2. f 7. m 12. k 3. a 8. n 13. h 4. o 9. l 14. g 5. b 10. e 15. j References K to 12 BASIC EDUCATION CURRICULUM JUNIOR HIGH SCHOOL (JHS) SPECIAL SCIENCE PROGRAM (SSP) – TLE (CREATIVE TECHNOLOGIES 15