| Abdul Ahad's Robotic Vehicles Program |
|
Inspired by the highly successful Mars Pathfinder mission of summer 1997, the AA Institute of Space Science & Technology embarked on a program of acquisition and subsequent enhancement of ground vehicles in an effort to develop remote exploration capabilities using �tele-robotics�. The initial acquisition was a pair of micro-rovers (Phase-1 vehicles) of miniature size but with significant terrain handling capability. These were imported from a manufacturer based in Saskatchewan, Canada via a UK electronics retailer, on special order, back in March 2002. These micro-rovers played an integral part in the Institute�s Mars Surface Simulations (MSS) project completed over summer 2002. AAI�s robotic vehicles program has since advanced to a �Phase 2� micro-rover , with significant enhancements to the camera scan platform which allows the mission operator full 360-degree rotation flexibility to be able to remotely point the camera at objects of particular interest in the rover's surrounding planetary landscape. The rover's 'instrumentation platform' has also been enhanced to house additional science instruments, including an analogue Magnetometer (for directional and field strength measurements), an Infrared Spectrometer plus an Atmospheric Precipitation Detector (APD) which detects moisture accumulating from the planetary atmosphere. By virtue of bigger size, the Phase 2 rover also has greater surface mobility capabilities. Phase 1 Micro-RoversBelow is an engineering schematic of a Phase 1 vehicle. It features independently controllable, digitally proportioned, left-right �caterpillar� drive belt wheels and a fixed, forward pointed remote sensing wireless video camera transmitting live video on a terrestrial TV channel frequency in the UHF wave band. The terrain handling capabilities were superb, so long as there are no rocks of more than 5mm diameter in the rover�s path of travel! This latter limitation was offset by a super 60-degree gradient climbing capability, thanks to the high traction caterpillar drive belts controlling the phase-1 micro-rover's wheels. This proved essential for navigating rough terrain on my model Mars surface, in particular, the steep walls of a long Valles Marineris-type feature named "Canyon Vibernium".![Micro-rover engineering schematic [Credit: Abdul Ahad]](image001.jpg)
The �Earth-Mars� radio response rate was sound, with uplink commands sent optionally either manually or by computer on an uplink digital channel frequency in the 27 MHz band. The downlink TV images could be received and processed on a Sony 14-inch monitor using a standard UHF reception antenna at AA Institute�s Mission Control facility, located some 25m away from the exploration site. (Incidentally, because of the close proximity in these simulations between "mission control" (on Earth) and "Mars", there was no light-time delays to worry over and all transmissions were sent/received virtually in real time!). Here are some images of the rover roaming the red Martian deserts on my model Mars surface: ![Micro-rover on simulated Mars terrain [Credit: Abdul Ahad]](image003.jpg)
![Micro-rover on simulated Mars terrain [Credit: Abdul Ahad]](image005.jpg)
Robotic Vehicle On-board Power SystemsA phase 1 micro-rover operated on 2 x 3v Lithium photo batteries which powered the wheel motors and �motherboard� circuits comprising a microprocessor and downlink radio receiver. The on-board remote sensing UHF camera worked off a separate 9v Ni-MH rechargeable cell, which took a massive 15 hours to fully charge up and giving only a 60 to 90 minute continuous running time.With the AAI phase 2 micro-rover, power systems became much more complex, with up to 5 distinct sets of rechargeable batteries required to power the rover�s wheels, on-board radio and science instruments, camera and steerable camera scan platform:-
In summary, my phase 2 micro-rover's power systems take 40 hours to fully charge using a conventional Uniross "fast charger" and provide functionality for no more than 1.5 to 2 hours continuous running time. Exploration simulations therefore had to be done fairly quickly! The AA Institute has been swift to respond to this challenge. Recent investments in additional state of the art solar panels now ensure continuous zero-cost charging during daylight hours, rotating batteries across the full range of rover components. ![AA Institute's phase-2 micro-rover [Credit: Abdul Ahad]](phase2vehicle2.jpg)
Click here for schematic images of the Phase 2 Micro-Rover A view from the rover's perspective: a digital image of how a Phase 2 Micro-Rover "sees" the landscape ahead while driving. ReferencesWant to build your own planetary surface exploration vehicle?Visit the AAI online shopping portal for a choice of books that can help you build your own robots! The movie "Mission to Mars" available on DVD, features a tiny six wheeled Mars micro-rover remotely controlled by human operators, buy it online here. Roadmap for Future CapabilitiesSome broad areas which AAI may consider for future study:
AA Institute of Space Science & Technology Home Page |
