ISM 101Gabriel Hugh Elkaim 1 ISM 101 Guest Lecture on Robotics and Control 24.Feb.2005 Gabriel Hugh Elkaim

ISM 101Gabriel Hugh Elkaim 2 Assistant Professor Computer Engineering 353B Baskin Engineering (831) Gabriel Hugh Elkaim Background: Aerospace Engineering Interest: Robotics/Embedded Systems

ISM 101Gabriel Hugh Elkaim 3 ASL LAB Santa Cruz Autonomous Systems LabSanta Cruz Autonomous Systems Lab Robotics and Embedded SystemsRobotics and Embedded Systems Sensor FusionSensor Fusion Robust Software DesignRobust Software Design

ISM 101Gabriel Hugh Elkaim 4 Relevant Expertise Feedback Control SystemsFeedback Control Systems Embedded System Software/HardwareEmbedded System Software/Hardware Mechatronic DesignMechatronic Design Microcontroller/DSP projectsMicrocontroller/DSP projects Navigation/Guidance SystemsNavigation/Guidance Systems Global Positioning SystemGlobal Positioning System

ISM 101Gabriel Hugh Elkaim 5 Relevance to ISM Autonomous Mobile Platforms depend on: Sensing – environment, position, pose or attitude, obstacles, etc.Sensing – environment, position, pose or attitude, obstacles, etc. Path Planning (traditional A/I) – given the environment, get to objectivePath Planning (traditional A/I) – given the environment, get to objective Control – How do you track the trajectory that you have generatedControl – How do you track the trajectory that you have generated

ISM 101Gabriel Hugh Elkaim 6 Outline Robotics in generalRobotics in general Sensors in generalSensors in general –Types of Sensors –Filtering Issues Control in generalControl in general –PID (Proportional Integral Derivative Control) –Example, 3 wheeled ground vehicle

ISM 101Gabriel Hugh Elkaim 7 Robotics Czech word Robota means compulsory labor. “Rosum’s Universal Robots” written in 1920 by Czechoslovakian author Karel Capeck Robotics: technology dealing with the design, construction, and operation of robots.

ISM 101Gabriel Hugh Elkaim 8 Robots According to Merriam-Webster: 1 a : a machine that looks like a human being and performs various complex acts (as walking or talking) of a human being; also : a similar but fictional machine whose lack of capacity for human emotions is often emphasized b : an efficient insensitive person who functions automatically 2 : a device that automatically performs complicated often repetitive tasks 3 : a mechanism guided by automatic controls

ISM 101Gabriel Hugh Elkaim 9 My Definition Look at a Venn diagram of Mechanical and/or Electrical Hardware, Software, and Control Systems.Look at a Venn diagram of Mechanical and/or Electrical Hardware, Software, and Control Systems. Robotics is the overlapping area at the center of the threeRobotics is the overlapping area at the center of the three GNC Mechanical Software Robotics

ISM 101Gabriel Hugh Elkaim 10 What are some of the Issues? ConfigurationConfiguration –What mechanical scheme do you need to complete the mission –Example: UAV that deploys from a type “A” sonobuoy (36” long x 4.875” in diameter) –Example: Pipe Inspection must negotiate 90 degree bends, self contained, etc.

ISM 101Gabriel Hugh Elkaim 11 Navigation How do you know where you are?How do you know where you are? –Outdoors –Underwater –In Space –Indoors –Underground

ISM 101Gabriel Hugh Elkaim 12 Guidance Where do you want to go?Where do you want to go? How fast do you need to get there?How fast do you need to get there? Is there anything in the way?Is there anything in the way?

ISM 101Gabriel Hugh Elkaim 13 Control How do you get from where you are, to where you want to go?How do you get from where you are, to where you want to go? What if something is not as predictedWhat if something is not as predicted

ISM 101Gabriel Hugh Elkaim 14 Odometry

ISM 101Gabriel Hugh Elkaim 15 GPS – Global Positioning System

ISM 101Gabriel Hugh Elkaim 16 Inertials

ISM 101Gabriel Hugh Elkaim 17 Attitude

ISM 101Gabriel Hugh Elkaim 18 Control Issues Get the device to do what it is commandedGet the device to do what it is commanded Open Loop ControlOpen Loop Control Feedback ControlFeedback Control –Must have a sensor –Increases Disturbance Rejection –Decreases Sensitivity to parameter variation Entire specialty of engineeringEntire specialty of engineering

ISM 101Gabriel Hugh Elkaim 19 Examples of Control Systems Toilet BowlToilet Bowl Cruise ControlCruise Control Thermostat on HouseThermostat on House Missile Guidance SystemMissile Guidance System Mobile Robot Obstacle AvoidanceMobile Robot Obstacle Avoidance Many, many moreMany, many more

ISM 101Gabriel Hugh Elkaim 20 Cruise Control in Detail

ISM 101Gabriel Hugh Elkaim 21 Cruise Control – Open Loop

ISM 101Gabriel Hugh Elkaim 22 Cruise Control – Closed Loop

ISM 101Gabriel Hugh Elkaim 23 Generic Control System Block Diagram

ISM 101Gabriel Hugh Elkaim 24 Sensor Issues Dynamic RangeDynamic Range LinearityLinearity HysteresisHysteresis QuantizationQuantization Temperature EffectsTemperature Effects BandwidthBandwidth

ISM 101Gabriel Hugh Elkaim 25 Sensors – Linearity

ISM 101Gabriel Hugh Elkaim 26 Sensors – Dynamic Range

ISM 101Gabriel Hugh Elkaim 27 Sensors – Hysteresis

ISM 101Gabriel Hugh Elkaim 28 Sensors – Quantization

ISM 101Gabriel Hugh Elkaim 29 Sensors – Temperature Effects

ISM 101Gabriel Hugh Elkaim 30 Sensors – Bandwidth

ISM 101Gabriel Hugh Elkaim 31 Actuator Issues Power / StrengthPower / Strength LinearityLinearity HysteresisHysteresis QuantizationQuantization Temperature EffectsTemperature Effects BandwidthBandwidth

ISM 101Gabriel Hugh Elkaim 32 Control System – PID ProportionalProportional IntegralIntegral DerivativeDerivative

ISM 101Gabriel Hugh Elkaim 33 Control System – Motor Drive

ISM 101Gabriel Hugh Elkaim 34 Control System – Motor Drive

ISM 101Gabriel Hugh Elkaim 35 Control System – Voice Coil

ISM 101Gabriel Hugh Elkaim 36 Control System – Voice Coil

ISM 101Gabriel Hugh Elkaim 37 Control System – Heater

ISM 101Gabriel Hugh Elkaim 38 Control System – Heater

ISM 101Gabriel Hugh Elkaim 39 Control System – Motor Drive w/P

ISM 101Gabriel Hugh Elkaim 40 Control System – Voice Coil w/P

ISM 101Gabriel Hugh Elkaim 41 Control System – Heater w/P

ISM 101Gabriel Hugh Elkaim 42 Control System – Motor Drive w/I

ISM 101Gabriel Hugh Elkaim 43 Control System – Heater w/I

ISM 101Gabriel Hugh Elkaim 44 Control System – Motor Drive w/PI

ISM 101Gabriel Hugh Elkaim 45 Control System – Heater w/PI

ISM 101Gabriel Hugh Elkaim 46 Integrator Windup – Motor Drive w/PI

ISM 101Gabriel Hugh Elkaim 47 Integrator Limit – Motor Drive w/PI

ISM 101Gabriel Hugh Elkaim 48 Control System – Voice Coil w/PD

ISM 101Gabriel Hugh Elkaim 49 Control System – Heater w/PID

ISM 101Gabriel Hugh Elkaim 50 PID Controllers Proportional gain increases response speed, to much gain causes system to ring.Proportional gain increases response speed, to much gain causes system to ring. Integral gain kills steady-state error, wind- up and/or too much gain can cause system to go unstable.Integral gain kills steady-state error, wind- up and/or too much gain can cause system to go unstable. Derivative gain adds damping and stability, but is sensitive to jitter and noise.Derivative gain adds damping and stability, but is sensitive to jitter and noise.

ISM 101Gabriel Hugh Elkaim 51 Tuning PID Controllers Don’t need to understand Controls or System to use PID.Don’t need to understand Controls or System to use PID. Start with pure Derivative control.Start with pure Derivative control. Increase gain until system oscillates or you see over 50% overshoot.Increase gain until system oscillates or you see over 50% overshoot. Go up to verge of ringing, back off by a factor of 2 or 4.Go up to verge of ringing, back off by a factor of 2 or 4.

ISM 101Gabriel Hugh Elkaim 52 Tuning PID Controllers Start with Proportional gain, increase by factor of 8 to 10 until oscillation.Start with Proportional gain, increase by factor of 8 to 10 until oscillation. If it is already oscillating, decrease by factor of 8 to 10.If it is already oscillating, decrease by factor of 8 to 10. From verge of oscillation, back off by factor of 2 to 4.From verge of oscillation, back off by factor of 2 to 4.

ISM 101Gabriel Hugh Elkaim 53 Tuning PID Controllers Start with Integral gain very small, to 0.01.Start with Integral gain very small, to Increase until you get response you like.Increase until you get response you like. Be sure to implement anti-windup.Be sure to implement anti-windup. If you have problems, play with sample rate.If you have problems, play with sample rate.

ISM 101Gabriel Hugh Elkaim 54 A 3-Wheeled Vehicle

ISM 101Gabriel Hugh Elkaim 55 A 3-Wheeled Vehicle

ISM 101Gabriel Hugh Elkaim 56 A 3-Wheeled Vehicle

ISM 101Gabriel Hugh Elkaim 57 A 3-Wheeled Vehicle

ISM 101Gabriel Hugh Elkaim 58 A 3-Wheeled Vehicle