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U nited A rab E mirates U niversity C ollege of E ngineering G raduation P roject II. Vehicle Following System. Project Advisor: Dr. Hassan Noura Project Co-ordinator: Dr. Qurban Ali . Mohammad Saad Laghari 200235906 Saeed Aqeel Saeed 200305445 Badr Al-Salmy 200235572
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United Arab Emirates University College of Engineering Graduation Project II Vehicle FollowingSystem Project Advisor: Dr. Hassan Noura Project Co-ordinator: Dr. Qurban Ali Mohammad Saad Laghari 200235906 Saeed Aqeel Saeed 200305445 Badr Al-Salmy 200235572 Marwan Essa Bastaki 200540932 Second Semester 2007/2008
Contents Introduction Background Theory Mathematical Modeling Digital Control Sensor Microcontroller Motor Switching Function System Structure and Final Design Gantt Chart for GPI Gantt Chart for GPII Conclusion
Make the 2nd car follow the 1st car 1st car remote controlled 2nd car autonomous motion by keeping the distance constant using a digital control system Safety Factor Environmental Factor
The team objective is to design this system and develop the controller that allows achieving the vehicle following system Necessary instruments to complete the project are: • Sensors • Micro-controller • H-bridges • Mosfets • Circuit Components • Etc.
The team work includes: • Design & construction • Instrumentation • Computer modeling & analysis • Implementation and control • Testing & experimental investigation
Both cars are to communicate via a communication system (transmitter – receiver) set • A control system has to be installed on the follower car • This will allow it to start into motion when the first car does and stop when the first car stops, keeping a predetermined distance • The control system basically includes some computer software which translates the logic of motion of the follower car • This software is to be installed onto an appropriate micro – controller chip
Applications and Uses Decrease man-power (lower cost and time, more work) Pesticide Control (Farming) Transportation Manufacturing Carriages Automated High-ways
Cars Speed Deceleration Weight Size Circuitry of Motor Price
Communication Ultra-sonic Only frequency around 40KHz is detected Distance increases, Voltage decreases (vice-versa)
Microcontroller & Motor The peak voltage received from receiver is received by micro-controller Micro-controller determines if the voltage is nominal (set voltage) using simple microprogramming codes Micro-controller then sends a signal to the H-bridges The H-bridges then sends the signals to the powere MOSFETs, which in turn send the signals to the motors
The 2nd Car’s body coordinates Define :
This model is not complete, since the state space should include input voltages (or currents).
J = Mass moment of inertia kτ = Torque Constant B = Friction of Motor
Main Parts of a Digital Controller • A/D conversion • D/A conversion • A program
Ultra-sonic Sensors • Systems typically use a transducer which generates sound waves in the ultrasonic range, above 20,000 hertz, • by turning electrical energy into sound, • then upon receiving the echo • turn the sound waves into electrical energy which can be measured and displayed
Transducer • An ultrasonic transducer is a device that converts energy into ultrasound, or sound waves above the normal range of human hearing • Piezoelectric crystals: • Changing size when a voltage is applied • Applying an alternating voltage (AC) across them causes them to oscillate at very high frequencies • Thus producing very high frequency sound waves
Detectors • Since piezoelectric crystals generate a voltage when force is applied to them, the same crystal can be used as an ultrasonic detector • Since the detector will only be used to detect ultrasonic waves, the design is such a way that all other waves (or most of them) are eliminated
Receiver Transmitter
Frequency = 40 KHz Input Voltage = 14Vpp
CAR 1 CAR 2
15 cm 5 cm 1.2 mm
Logic Angle Sensors: Programming Both increase or both decrease Right sensor increases, Left decreases car turns right Left sensor increases, Right decreases car turns left
PIC16F877 InputH and InputL: 0-0.5V 2.0-5.5V OutputH and OutputL: 0-0.7V 4.2-5V