CEEN Bot Lab Design by Deborah Duran (EENG) Kenneth Townsend (EENG) A SENIOR THESIS PROPOSAL Presented to the Faculty of The Computer and Electronics Engineering Department In Partial Fulfillment of Requirements For CEEN 4980 Senior Thesis Proposal Major: Electronics Engineering The University of Nebraska-Lincoln, Omaha Campus Spring, 2004
3702 N. 65 th Ave. Omaha, NE 68104-3250 January 30, 2004 Computer and Electronics Engineering Department University of Nebraska-Lincoln, Omaha Campus 60th & Dodge St. Omaha, NE 68182 The accompanying Senior Thesis Proposal, " CEEN Bot Lab Design is submitted in accordance with the requirements of CEEN 4980, Senior Thesis. As stated in the proposal, the project will be completed for and funded by the Computer and Electronics Engineering Department. The laboratory project ideas were designed in accordance with the requests of Professor Herb Detloff and Professor Thad Kulik, for application in specified CEEN laboratory courses. Dr. Bing Chen, department chair, has reviewed this proposal and found that it meets the needs of the department. Respectfully yours, Deborah Duran Kenneth Townsend 1
TABLE OF CONTENTS I. BACKGROUND....3 II. THESIS OVERVIEW 3 III. GENERAL DESCRIPTION....4 IV. COMPONENTS LIST.....8 V. TIME SCHEDULE.. 9 VI. ACCEPTANCE TESTING...10 VII. TEAM MEMBERS......11 VIII. MEMBER ASSIGNMENT.... 11 IX. SUMMARY..12 2
I. BACKGROUND The chair of the department, Dr. Bing Chen, has a vision of integrating robotics into the CEEN curriculum as a means of cohesively joining together engineering coursework onto a single design platform. To this end, he has asked for the development of laboratory exercises, using the Parallax Boe Bot robot platform, which would fit into existing laboratory courses. These design modules are to be completed on the PCB designed by Andrew Reynolds, if possible; effectively transforming the platform into what will be named the CEEN Bot. It is required to work with professors from the department in order to ensure that laboratory activities are appropriate for the courses in which they will be deployed. Our goal is to produce three such design laboratories for the department, as well as to design our own simple wireless application for these robots. The department has agreed to fund such development activities. II. THESIS OVERVIEW The final outcome of this thesis will be subdivided into four objectives: First, the robot will be able to autonomously detect and avoid collisions with objects. Second, the robot will be able to change directions by means of a specific series of handclaps. Third, the robot will be able to digitally record and play back voice audio data for a specified time period. Finally, one robot will be able to transmit recorded voice audio data to other specific robots wirelessly, and then clear its memory for security purposes. All of these objectives are to be achieved using only battery power, although the PCB provides a jack for AC wall power (for testing). 3
III. GENERAL DESCRIPTION Figure 1 depicts the basic movement and collision avoidance module without using the processor that comes standard with such robots. This module is to be developed for CEEN 2184 - Electrical Circuits 1 Laboratory. The robot is initially moving forward upon startup. When a sensor detects an object (at least 6 away, physical presence at 3 1/2 vertical from bottom of wheels, 4 wide, IR reflective material for IR sensors, unyielding material for bump sensors), it will activate a timer for the opposite servo, causing the servo to run backwards long enough to complete a 90 (±5 ) turn. Once the turn is finished, the robot will again continue to move forward. If both sides sensor timers are activated during a turn, the robot will travel backwards for the time of one turn duration (time not specified yet, dependent on 90 turning time), then turn 90 (±5 ) right or left, whichever is easier to implement in hardware, thus avoiding conflicts between two opposite sensors. Pulse Train Generators Left Wheel Servo Pulse Train Selector Control Logic Pulse Train Selector Right Wheel Servo Left Sensors (IR, bump sensors) Left Sensor One-Shot Timer Right Sensor One-Shot Timer Right Sensors (IR, bump sensors) Figure 1: Autonomous Collision Avoidance Block Diagram 4
In Figure Two below, the function of the robot is extended to directional response using a specified series of claps, which will be acquired by the microphone and preamplifier within at least a 15 range for normal clap strength (will be demonstrated for testing). This module is developed for CEEN 2234 Electronics I Laboratory. The robot interface (a manually switched mode selection interface) is introduced as a method of making the sensory devices available to different control modes. Once the clap control mode is enabled, the microphone is monitored through a band pass filter for the specific frequency of human claps. The control device stops the robot and waits for a short time after each clap, then counts the number of claps it has received so far. On command, it will be able to turn left, right, move forward or backward, and stop. Microphone Pulse Train Generators Left Wheel Servo Pulse Train Selector Pulse Train Selector Left Sensors (IR, bump sensors) Left Sensor One-Shot Timer Right Sensor One-Shot Timer Control Device Robot Interface Preamp BP Filter Right Wheel Servo Right Sensors (IR, bump sensors) Figure 2: Clap Control Block Diagram 5
In Figure 3 below, the digital voice recorder currently studied in CEEN 3520 Electronics II will be redesigned to interface with the robot and run on a battery supply. The main features of this module are: the robot interface allowing access to the microphone and speaker for this mode; the design of a preamplifier and anti-aliasing filter; the control of a codec and memory device by a microcontroller or PLD to acquire at least 10 seconds of voice data and play it back on command; design of a power amplifier stage to control volume output of acquired voice to an 8 ohm speaker; and the introduction to device shielding, which can be done with metal casings of various types, even aluminum foil for those under strict budget constraints. Microphone Amplification/ Filtering Memory Device Robot Interface Coder/ Decoder Speaker Power Amplification Control Device Shielding for noise reduction Figure 3. Digital Voice Recorder Block Diagram 6
In Figure 4 below, an exploration of wireless communication between robots is undertaken. Using the previously developed modules, one robot (manually selected as the transmitting robot by the robot interface) will be able to move by clap control (15 clap control range), record voice data, transmit it wirelessly to another robot (manually selected as the receiving robot by the robot interface, addressed by a wireless control code to differentiate among multiple receivers, at least 50 transmission range), and then clear its data memory. The receiving robot(s) will then be able to return with the voice data. Here, the robot interface allows access to the transmitter by the control device, a microcontroller. Separate memory modules may be used here, as well as data processing hardware to format data for transmission and reception by the control device. This module is not being developed for a specific course, but is being done to demonstrate some of the potential applications of these robots. Memory Access Robot Interface Microcontroller Data Processing TX/RX Robot Module AWGN Memory Access Robot Interface Data Processing TX/RX Microcontroller Robot Module Figure 4. Wireless Application Block Diagram 7
IV. COMPONENTS LIST COMPONENT CATEGORY PART NUMBER QUANTITY COST 555 Timer 27422CA 12 $3.24 Push Button Switch 149948CA pkg $2.30 Speaker (8 Ohm) 135765CA 2 $3.18 Microphone 136573CA 2 $1.06 8051 Flash AT89C52-24PC-ND 2 $7.52 Diode Bridge W04GGI-ND 4 $1.84 Toggle Switch CKN1182-ND 2 $16.92 9 Volt Battery P145-ND 12 (pkg) $17.04 1.5 Volt Battery P107-ND 40(pkg) $14.40 DB25 Cable 67256CA 1 $6.45 RS232 Solder Socket 37372CA 2 $0.20 Static RAM 131810CA 2 $17.90 MAX232CPE 24811CA 2 $4.38 Dual 4-1 Selector 46720CA 4 $1.16 Serial Shift Register 45487CA 2 $0.62 Parallel load 8 bit Shift Register 45495CA 2 $0.66 5-Volt Regulator (Low drop out) 107182CA 4 $5.16 9 volt Battery Holder 105793CA 2 $0.56 40 pin Universal ZIF socket 104029CA 2 $22.50 40 pin Wire Wrap Socket 94502CA 2 $5.32 24 pin Wire Wrap Socket 105371CA 1 $1.49 8 pin Wire Wrap Socket 94473CA 2 $1.06 20 pin Wire Wrap Socket 38631CA 2 $2.66 22 pin Wire Wrap Socket 185324CA 4 $5.40 PCB Boards 105136CA 4 $39.80 24 pin ID Marker 39327CA 6 $7.08 20 pin ID Marker 38586CA 2 $1.10.100 Straight Male Headers 109575CA 10 $1.70 Wire Wrap Wire 22576CA 1 $4.95 Wire Wrap Wire 22630CA 1 $4.95 Crystal Oscillator 27967CA 2 $3.98 Oscillator Socket 133006CA 2 $1.10 Transceiver Modules TBD 2 $150.00 TOTAL COST: $501.55 Figure 5: Estimated Component Budget (items already belonging to Dept. not shown) 8
V. TIME SCHEDULE Week of: Collision Avoidance: Test servos Design / test sensors Design / test timers Design / test generators Design / test selectors Design / test logic Clap Control: Design / test microphone Design / test interface Design / test preamp Design / test BP filter Design / test controller Controller interface DVR Design: Design / test amp / filter Design / test codec Design / test controller Design / test memory Design / test power amp Design / test speaker Design / test interface Controller interface Wireless Application: Design / test TRX mod Design / test data proc. Design / test controller Design / test memory Design / test interface Controller interface Common Tasks: Parts ordering Documentation Debugging Final testing Final report assembly Prep. for demonstration Figure 6: Gantt Chart Timeline for Completion of "CEEN - Bot" Senior Thesis Tasks Spring 2004 February March April May F 1-6 F 7-13 F 14-20 F 21-27 F 28 - M 5 M 6-12 M 13-19 M 20-26 M 27 - A 2 A 3-9 A 10-16 A 17-23 A 24-30 M 1-7 9
VI. ACCEPTANCE TESTING Tasks the robot will be able to accomplish for each phase of development: Avoidance Detection: The robot will freely run in a forward direction, until it senses an obstacle 6 away. The robot will turn to avoid the obstacle, given the obstacle is at the sensor s height level off the ground, and the obstacle is wide enough to be detected (see p.4 for specs). The robot may hit an obstacle while it is avoiding another. Clap Control: The robot will have its obstacle detection mode available. The robot will respond to a clap ( normal clap strength, at least 15 range), stop, and count further claps occurring within 1 second of the last clap. The robot will be able to stop, run forward, turn right 90 (±5 ), turn left 90 (±5 ), and run in reverse based on the number of claps counted (1-5, order yet to be determined). Digital Voice Recorder: The robot has its normal clap controls enabled (see above), until it counts 6 or 7 claps. The robot will, upon counting 7 claps, stop & digitally record 10 seconds of voice data with onboard microphone. The robot will, upon counting 6 claps, stop & digitally play back 10 seconds of voice data on onboard speaker. Wireless Application: The robots will have unique digital identifiers assigned to them for reception purposes. The robots will be able to wirelessly transmit (50 range), one at a time (half duplex), to all or uniquely selected robots, or receive, when manually set in transmission mode. The robots will be able to wirelessly receive when manually set in reception mode, and clap controls are disabled until needed (one robot clap controlled at a time). The transmitting robot will be controlled by claps, or by a remote control. When it receives the command to play back, it will transmit its data wirelessly to a uniquely selected robot, then clear the data from memory and disable its controls if clap controlled. The uniquely selected receiving robot will then enable its clap controls, and be able to play back the transmitted data on clap command. These specifications will be tested and approved by the involved faculty. 10
VII. TEAM MEMBERS Deborah Duran Kenneth Townsend VIII. MEMBER ASSIGNMENT Figure 7: Responsibility for Completion of "CEEN - Bot" Senior Thesis Tasks by Member Spring 2004 Responsible Party & Responsibility Level Collision Avoidance: Test servos Design / test sensors Design / test timers Design / test generators Design / test selectors Design / test logic Clap Control: Design / test microphone Design / test interface Design / test preamp Design / test BP filter Design / test controller Controller interface DVR Design: Design / test amp / filter Design / test codec Design / test controller Design / test memory Design / test power amp Design / test speaker Design / test interface Controller interface Wireless Application: Design / test TRX mod Design / test data proc. Design / test controller Design / test memory Design / test interface Controller interface Common Tasks: Parts ordering Documentation Debugging Final testing Final report assembly Prep. for demonstration Deborah Duran Kenneth Townsend Primary Secondary Primary Secondary 11
IX. SUMMARY In conclusion, the end result of this senior thesis will be at least two CEEN Bot prototypes which demonstrate 4 distinct modes of operation: free-running object detection and avoidance; clap-signaled motion and direction control; voice data acquisition and playback; and wireless half-duplex communication with unique robot identifiers. These prototypes will be turned over to the CEEN department with full documentation included, allowing the results to be duplicated as laboratory projects in courses CEEN 2184, CEEN 2234, and CEEN 3520, with ideas for further CEEN Bot research suggested. The main reason for this choice of thesis topic is that before the junior/senior years, students in the CEEN program get very little project management and design experience, see very little direct application of their newfound knowledge, and do not create so-called artifacts to chart their learning progress. As they will be required to purchase these Parallax robots for CEEN 1060, it makes sense to further expand on such an expensive device with such limitless learning potential, and to produce a neat gadget that is uniquely identifiable to our program. Also, the students will be shown immediately that: the devices and components they are studying have a direct application in the real world, even down to the simple resistor; that IC logic abstractions and control function design need sound design principles and appropriate interfacing to make them work effectively; and that the computers, logic circuitry and devices they are learning about can be, and are in fact, used to control the physical devices found in robotics construction. 12