Revised PSSCs An ability to navigate to programmed waypoints. An ability to remotely control the robot’s motion and camera. An ability to autonomously detect and maneuver around obstacles. An ability to remotely monitor the robot’s location. An ability to remotely monitor the battery life of the robot.
Important Constraints Speed of the MCU. High computations required by the project. Should be able to quickly complete one task and move to the other. Accuracy of the GPS chip. Should have a good refresh rate. Should be precise while determining coordinates. Range of wireless camera and the transceivers. Both wireless camera and the transceivers should have a good range (300 – 400m). The range should be in sync, such that the camera should not have a lesser range compared to the transceivers and vice-versa. Size and weight of the vehicle. The vehicle size should be large enough to accommodate all components. The base of the vehicle should be sturdy enough to handle the weight of the components including the on-board battery. Range of the Ultrasonic and Infra-Red sensors. The Ultrasonic sensor should be precise enough to detect obstacles in front of the robot (within 6 in). The Infra-Red sensor is used to detect potholes and hence we need it to be precise enough within 10-12 in.
Component Rationale Micro-Controller PIC32MX512 from Microchip Technologies High frequency (80 Mhz). 86 I/O pins. MIPS Architecture. Cheap ($9 per unit) MCF52258AG80 from Freescale Semiconductor High frequency (80 Mhz). 96 I/O pins (too many!). Coldfire Architecture (not familiar). Comparatively expensive ($12 per unit).
Component Rationale Camera QSWLOCR from Q-See Good Range (upto 300 feet). S-video output. Lots of unnecessary features. Kind of difficult to set up due to extra features. Cost : $60 NIGHT-WIRELESS Good Range (upto 300m). Co-axial output for video. Comparatively lesser features, but the ones required present. Easy to set up. Cost : $40
Component Rationale Wireless Protocol and GPS Wireless Protocol Wifi Limited range. Comparatively less noise during data transmission. Bluetooth Limited Range, even lesser than Wifi. Less noise during data transmission. Radio Frequency Excellent range : upto 300 – 400 meters. Most data loss due to high noise levels. GPS Chip EM-406A Precise, but low refresh rate. No inbuilt compass. SPI interface. LS 20126 Precise and good refresh rate. Inbuilt compass. UART interface.