1 / 37

Wireless Bluetooth Controller For DC Motor

Wireless Bluetooth Controller For DC Motor. ECE 445 Spring 2007 TA: Brian Raczkowski Professor Gary Swenson. Project #5 Abhay Jain Reid Vaccari. April 26, 2007. Abhay Jain. Reid Vaccari. Group #5. Introduction. Motivation:. Wireless becoming more and more available and widely used

hagop
Download Presentation

Wireless Bluetooth Controller For DC Motor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Wireless Bluetooth Controller For DC Motor ECE 445 Spring 2007 TA: Brian Raczkowski Professor Gary Swenson Project #5 Abhay Jain Reid Vaccari April 26, 2007

  2. Abhay Jain Reid Vaccari Group #5

  3. Introduction Motivation: • Wireless becoming more and more available and widely used • Bluetooth is one of the major players • Interested in power and motor control

  4. Objectives Features: • Wireless Controller for DC Motor • Bluetooth Wireless Standard • Windows based GUI • 12 V Permanent Magnet Geared Motor • Battery powered • Variable speed

  5. Objectives Benefits: • Practical • Provides Flexibility • Economical • User-friendly • Can be ran from any PC running Windows

  6. Applications • Robotics • Remote control car • Industrial Uses • Household Uses

  7. Design Specs • Output voltage varying from 0-12 Vdc • Adjustable speed from 0 to 95 RPM and 0 to 6222 RPM on load side • Motor can turn in both directions • Continuous motor loads of 15 W • Maximum motor torque of 2.12 N-m • Wireless control up to 60 feet

  8. Block Diagram

  9. Hardware Layout

  10. Full Schematic

  11. User Interface • GUI developed in Visual C++ • User can accelerate, decelerate, start and stop motor • Motor direction can be chosen • Speed referenced to lower geared side • Maximum speed setpoint of 95 RPM • Displays Load side RPM as well

  12. User Interface • Speed is output to serial port by software • Control signal specifies direction • Transmitted via USB Bluetooth Module • When Stopped, speed is ramped down • Same for direction switch

  13. User Interface

  14. User Interface

  15. Bluetooth PC Side: • Bluetooth USB Receiver for PC • Set up as COM port • Transmits USART serial data to WML-C40 Bluetooth Module

  16. Bluetooth Motor Side: • BlueSMIRF WML-C40 Module • Vcc = 5 V, with internal regulator • Receives USART serial data from USB module • Transmits to PIC16F877 via serial TX

  17. Microcontroller • PIC16F877 40 pin DIP • Programmed in C using CSS Compiler • Receives speed control signal from user software • Translates desired speed to necessary duty cycle • 16 kHz internal clock used for timers • Sends duty cycle to H-bridge inputs using onboard PWMs

  18. H-Bridge • NJM2670D2-ND Dual H-Bridge Driver • Consists of 4 MOSFETS as switches • Duty cycle determines speed by controlling how long switches are active • Motor direction can be controlled • IN1 and IN2 fed from PWM • Adjusted voltage is output to motor terminals

  19. H-Bridge Image from Wikipedia

  20. Motor • Pittman GM9434 12 V Permanent Magnet DC Motor • 65.5:1 Gear Ratio • Max Rated Motor Speed = 93.9 RPM • Max Rated Torque = 2.12 N-m

  21. Functional Tests • Used HyperTerminal to get initial connection between Bluetooth Modules and another PC acting as the PIC • Sent serial input to PIC, tested basic outputs (LED, serial text echo) • Tested H-Bridge using hardwired controls to verify functionality • Motor operation verified using battery

  22. Operation Tests • For a given duty cycle, the resulting speed was measured • Using a collection of these points, a linear translation from duty cycle to speed was calculated • @ 2 RPM: Duty cycle = 110 • @ 108 RPM: Duty cycle = 950 • Y = mx + b  Duty = 7.92(speed) + 94.15

  23. Challenges • Replaced Voltage Divider consisting of resistors with Voltage Regulators • Original H-Bridge was Surface Mount • Replaced expired Bluetooth module with simpler model with internal voltage regulation • ASCII Translation Issues • Converting string control signal to usable decimal integer

  24. Successes • No voltage issues after switching to regulators • Solved ASCII formatting issues • New H-Bridge was capable • PWM operations didn’t provide difficulties

  25. Motor Operations • No-Load Motor Current vs. Terminal Voltage

  26. Motor Operations • Max Load Motor Current vs. Terminal Voltage Recommended Max H-Bridge Current = 1.2 A

  27. Results • Motor ran in both directions • 0-95 RPM on lower geared side • 0-6222 RPM on load side • Maximum continuous load = 15 W • Maximum continuous torque = 1.33 N-m

  28. Results

  29. Duty Cycle to H-Bridge PIC To H-Bridge Control Signal @ 48 RPM PIC To H-Bridge Control Signal @ 5 RPM

  30. Motor Duty Cycle Motor Voltage @ 48 RPM Motor Voltage @ 5 RPM

  31. Next Step • Designed feedback loop for closed system control • Installed Fairchild H21A1 Phototransistor Optocoupler • Designed optical encoder wheel on motor shaft with one notch to read RPM • Directed signal to PIC, began programming

  32. Next Step

  33. Next Step • Feed Forward can provide very tight speed control when load is known • With Feedback implemented, will respond to change in load and compensate • PDA instead of laptop

  34. Recommendations • Use an H-bridge with high current rating to maximize power produced • PIC Programming: C over Assembly • Stable Voltage Regulators = Good • Size Motor and components based on power needs

  35. Thank You • Brian Raczkowski • Alex Spektor • Wally Smith & Frank Dale (Parts Shop) • Scott McDonald (Machine Shop)

  36. Thank You

More Related