Robotic Arm Project Presentation This presentation will probably involve audience discussion, which will create action items. Use PowerPoint to keep track of these action items during your presentation In Slide Show, click on the right mouse button Select “Meeting Minder” Select the “Action Items” tab Type in action items as they come up Click OK to dismiss this box This will automatically create an Action Item slide at the end of your presentation with your points entered. Robotic Arm Project Presentation Project Leader : Gregg Sutton Education Lead: Alyssa Anglin Programming Lead: Rachael Voss Mechanical Design Team: Zachary Wood and Sarah Furrow

Robotic Arm 9/20/2018

Presentation Outline Project Overview Task Descriptions Status 9/20/2018

Robotic Arm Overview Assists students in learning educational concepts. Simulates the human arm. Controlled using a SiLabs C8051F310 microcontroller. Software developed in C (or assembly) using Silicon Laboratories software. 9/20/2018

The Robotic Arm Shall: be cost effective. model a human arm. have the ability to lift a tennis ball or full soft drink can. be as safe as possible! 9/20/2018

Robotic Arm Overview M M M Microcontroller SiLabs C8051F310 M M M Overall schematic showing signal flow between the microcontroller, the h-bridge motor drivers, the motors, and the input controller. M Input Controller M M Dual H-Bridge Microcontroller SiLabs C8051F310 Dual H-Bridge M Dual H-Bridge M M 9/20/2018

Educational Objectives The robotic arm will teach students: mechanics of the human arm and its movement. control of the human arm. about robotics and engineering. basic circuitry. 9/20/2018

Educational Outline Human Arm Mechanics Robotic Arm Mechanics Interaction between muscles and bones Range of motion Robotic Arm Mechanics Sliders as individual inputs Range of motion (more limited) Gears and motors Robotic Arm Engineering Design Process Basic Circuitry Potentiometers (inputs) Microcontrollers (brain) 9/20/2018

Educational Activity Task: Students will be required to move the Robotic Arm to a specified location and pick up small object. Outcome: Students will learn about complexity of human arm movement. 9/20/2018

Mechanical Design The arm is constructed Mounting of H-bridge drivers and micro in progress Debugging mechanical operation Elbow joint Shoulder rotation servo Forearm servo Shoulder lift servo 9/20/2018

Analysis of Mechanical System Analyzed torque required to lift a one pound load. Determined additional requirements for servomotor selection. Strain and Stress analysis was not performed due to the fact that the arm will only move light loads. 9/20/2018

Gripper The selected gripper is: constructed of lightweight aluminum. able to open to four inches. able to lift a full soft drink can or tennis ball. donated last fall by www.stampbuilder.com . 9/20/2018

Arm Movement 9/20/2018

2D view of shoulder 9/20/2018

Shoulder Lift and Pivot Joint 9/20/2018

Forearm Rotation Joint 9/20/2018

Elbow Joint 9/20/2018

Electromechanical Design Determined interface of microcontroller, H-bridge drivers and servomotors Selection of servomotors Designing of electromechanical assemblies Designing of input controller 9/20/2018

Electromechanical Interaction The microcontroller will output direction and speed signals for each motor that will be sent to the H-Bridges, which in turn will be sent to the motors. The position of the motors, supplied by internal potentiometers, will be sent back to the microcontroller to control the automatic power off of the motors when the limit of a joint is reached. 9/20/2018

Electromechanical Interaction 9/20/2018

Selection of Microcontroller SiLabs C8051F310 Microcontroller Has 29 I/O ports 20 ports can be used for Analog to Digital conversion (we need 12 for all of the inputs) 16Kb of non-volatile flash memory UART interface for future projects to program movement, even possibly through LAN On chip hardware debugger with step through capabilities. Cheap! 9/20/2018

Selection of Servomotors The servomotors: purchased from HiTec RCD, USA, Inc. are sized for each joint based on torque requirements. include built-in circuitry (this was removed for control purposes) 9/20/2018

Selection of H-Bridge Drivers The H-Bridge Drivers: Purchased from Lynxmotion Voltage = 4.8v - 12vdc Peak Current = 2.0 amp (motors draw ≈ 50 mA) Each can drive two motors 9/20/2018

Designing of Input Controller provides students with an interface to controlling the arm. uses potentiometers to provide voltage input signals for each motor. is safe for students to use. 9/20/2018

Input controller operation Input controller will control the direction of the servomotor rotation. The middle of the controller will be a “null zone” corresponding to no movement Above the null zone will correspond to clockwise movement Below the null zone will correspond to counterclockwise movement 9/20/2018

Input Controller Operation INPUT CONTROLLER SLIDER DIAGRAM – GREGG’S RESPONSIBILITY 9/20/2018

Electronic Control System Design Determine control software strategy Inputs: feedback potentiometers and input controller Outputs: Speed and direction Safe shutdown procedure 9/20/2018

Robotic Arm Status Mechanical construction completed Electromechanical design completed Preliminary wiring completed Educational material for students completed 9/20/2018

Robotic Arm Next Steps Mechanical debugging Finalizing software Professionalize wiring User manual Educational lesson plan approval Estimated delivery date: April 2005 9/20/2018