Robotic Circuit Components Adapted from a presentation originally made available by Sookram Sobhan, Polytechnic University ssobha01@photon.poly.edu

Systems for Robotics Typical knowledgebase for the design and operation of robotics systems Dynamic system modeling and analysis Structural Components Feedback control Sensors and signal conditioning Actuators and power electronics Hardware/computer interfacing Computer programming

Key Components Power conversion unit Sensors Actuators Controller User interface Manipulator linkage Base

Robot Mechanism: Mechanical Elements Gear, rack, pinion, etc. Cam and Follower Inclined plane wedge Chain and sprocket Lever Slider-Crank Linkage

Using Piezoelectric Effect Sensors: I Human senses: sight, sound, touch, taste, and smell provide us vital information to function and survive Robot sensors: measure robot configuration/condition and its environment and send such information to robot controller as electronic signals (e.g., arm position, presence of toxic gas) Robots often need information that is beyond 5 human senses (e.g., ability to: see in the dark, detect tiny amounts of invisible radiation, measure movement that is too small or fast for the human eye to see) Accelerometer Using Piezoelectric Effect Flexiforce Sensor

Sensors: II Vision Sensor: e.g., to pick bins, perform inspection, etc. Part-Picking: Robot can handle work pieces that are randomly piled by using 3-D vision sensor. Since alignment operation, a special parts feeder, and an alignment pallete are not required, an automatic system can be constructed at low cost. In-Sight Vision Sensors

Sensors: III Force Sensor: e.g., parts fitting and insertion, force feedback in robotic surgery Parts fitting and insertion: Robots can do precise fitting and insertion of machine parts by using force sensor. A robot can insert parts that have the phases after matching their phases in addition to simply inserting them. It can automate high-skill jobs.

Infrared Ranging Sensor Sensors: IV Example Infrared Ranging Sensor KOALA ROBOT 6 ultrasonic sonar transducers to explore wide, open areas Obstacle detection over a wide range from 15cm to 3m 16 built-in infrared proximity sensors (range 5-20cm) Infrared sensors act as a “virtual bumper” and allow for negotiating tight spaces

Sensors: V Tilt sensors: e.g., to balance a robot Example Planar Bipedal Robot

Actuators: I Common robotic actuators utilize combinations of different electro-mechanical devices Synchronous motor Stepper motor AC servo motor Brushless DC servo motor Brushed DC servo motor http://www.ab.com/motion/servo/fseries.html

Actuators: II Pneumatic Cylinder Hydraulic Motor Stepper Motor DC Motor Pneumatic Motor Servo Motor

Controller Provide necessary intelligence to control the manipulator/mobile robot Process the sensory information and compute the control commands for the actuators to carry out specified tasks

Controller Hardware: I Storage devices: e.g., memory to store the control program and the state of the robot system obtained from the sensors

Controller Hardware: II Computational engine that computes the control commands Arduino Uno Microcontroller BASIC Stamp 2 Module

Controller Hardware: III Interface units: Hardware to interface digital controller with the external world (sensors and actuators) Operational Amplifiers Analog to Digital Converter LM358 LM358 LM1458 dual operational amplifier

Solenoid Valves A solenoid valve is an electromechanically operated valve. The valve is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports. Solenoid valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids. They are found in many application areas. Solenoids offer fast and safe switching, high reliability, long service life, good medium compatibility of the materials used, low control power and compact design.

Solenoid Valves Solenoid Valve

Fuses A fuse is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection. Its essential component is a metal wire or strip that melts when too much current flows, which interrupts the circuit in which it is connected. Short circuit, overloading, mismatched loads or device failure are the prime reasons for excessive current. A fuse interrupts excessive current (blows) so that further damage by overheating or fire is prevented.

Fuses Fuses

Relays Electrical devices that as they have current flowing through them in one circuit can switch on and off a current in a second circuit.

Power Converters A power converter is an electrical or electro-mechanical device for converting electrical energy. It may be converting AC to or from DC or just changing the voltage or frequency, or some combination of these. Power Converter undergoing Test