102CEM – Introduction to Aerospace Electronics

102CEM – Introduction to Aerospace Electronics

Consider an Unmanned Aerial Vehicle (UAV) of quadrotor design, as the one depicted in Figure 1

A UAV is equipped, amongst other sensors, with a stereo vision system to determine its position and orientation and subsequently map the environment it is operating in. The requirement for this vision-based system to function properly is adequate illumination conditions, where in case of poor illumination, an alarm should be raised that will force the UAV to activate its on-board illumination subsystem.

More than one sensors are integrated into the UAV and a data fusion method [2] is used to integrate the data. One of those additional sensors is an ultrasound sensor, the simplest sensor that provides distance measurements from various obstacles that can be found in the path of the UAV. If an obstacle is found in close vicinity to the UAV and within its path, the UAV will switch from its main mission to avoid the obstacle and when the danger has been avoided to continue with the normal operation.

Task 1: Light Illumination Sensing Subsystem (50% Mark) In this Task, you are asked to develop the illumination sensing subsystem. By utilizing appropriate components, create a sensor whose voltage should be proportional to the light intensity. For the LDR that is provided, a 2kΩ resistor is needed as the fixed resistance of the voltage divider. Low illumination conditions will give low voltage, while high illumination will give high voltage. The following basic components are to be used in this

Task. Any additional components that you consider to be essential for the completion of the task can also be used.

• 1 red LED

• 1 yellow LED

• 1 green LED

• Active Buzzer

• RGB LED

• 1 Push Button The following requirements are expected from the subsystem.

• The three individual LEDs (Green, Yellow, Red) will be used as the indicators for the illumination levels.

• The RGB LED will be used as the on-board illumination system.

• The active buzzer should be used as an auditory warning system.

• Voltage levels in the range 0 – 2Volts will be considered as poor illumination. In that case the red LED should turn on.

• Voltage levels in the range 2 – 2.5Volts will be considered as marginal illumination. In that case the yellow LED should turn on. • Voltage levels in the range 2.5 – 5Volts will be considered as good illumination. In that case the yellow LED should turn on.

• In the case of poor illumination, the RGB LED should illuminate a white color in full intensity, and the buzzer should make a beeping sound every 100msec.

• In the case of adequate illumination, the buzzer should make a beeping sound every 250msec. In this case, if the user desires it, he can turn on the RGB LED by using the Push Button. The in this case, the RGB LED should illuminate a white color at half intensity.

• In the case of good illumination, the buzzer and the RGB LED should be turned off.

Task 2: Obstacle Avoidance Subsystem (50% Mark) In this Task, you are asked to develop the obstacle avoidance subsystem based on the ultrasound sonar. Use the sonar to measure the distance from an object. The following basic components are to be used in this Task. Any additional components that you consider to be essential for the completion of the task can also be used. • Ultrasound sonar module.

• LCD Display

• Joystick Module

• RGB LED

• A potentiometer.

• An individual Push Button. The following requirements are expected from the subsystem.

• The main mission of the UAV is the exploration. This should be displayed as a message in the first line of the LCD display as a scrolling message. In the LCD display in the second line, it should display the distance from the obstacle.

• If the UAV is less than 20cm away from the object, then the UAV enters the obstacle avoidance phase. In this case a corresponding message should be displayed as a scrolling message in the first line of the LCD display.

• If the joystick is used at any point, then depending on the movement of the joystick (xaxis is forward/backwards, y-axis is left/right), a corresponding message should appear in the second line of the UAV along with the distance from the obstacle. If the push button of the joystick is pressed, then the x-axis controls the up/down.

• If the user wishes, then by using the Push Button, it can turn on the on-board illumination (RGB LED). The potentiometer can be used to control the intensity of the LED. Instructions for Report: The report should reflect on the work that you have done. A brief introduction and conclusion should be included. Marks will be taken for poor report presentation. For each task, the following parts should be included.

• Brief explanation for the requirements of the Task.

• Code that was written along with comments and explanation of the code.

• A fritzing design showing the designed system. • Pictures depicting the hardware implementation. • Visual proof (pictures and/or video) showing the proper operation of your circuit. • Brief explanation/comments on the results.