Reader Response Draft 2 of Mars Rover Mobility
From the article "Mars Exploration Rover Mobility and Robotic Arm Operational Performance"(Tunstel et al., 2005), for NASA Rovers Spirit and Opportunity to traverse the uneven surface of Mars, they are equipped with multiple features to aid with their mobility. Such features include high torque, all-wheel drive, with a double-ackerman steering system for the six-wheeled robotic rovers. A rocker-bogie suspension system allows the rovers to traverse the uneven ground with a level difference of 25 centimetres without tipping over and rolling by allowing all 6 wheels to be in contact with the ground at all times. Each rover also has multiple camera pairs. Front and rear camera pairs are mounted on the body for sensing and evading danger. While another camera pair is mounted at a fixed height of 1.3 metres above the ground and is used for global path planning and visual odometry. Visual odometry uses the images taken from the elevated camera pair to map out the terrain of Mars for autonomous control (Tunstel et al., 2005). The mobility of NASA Rovers Spirit and Opportunity was a key factor in the success of exploring the surface of Mars.
One of the key elements is the rocker-bogie suspension system, which allows all six wheels of the rovers to be in contact with the ground at all times. According to the article "Mars Exploration Rover Mobility Development" (Lindemann et al., June 2006), the center of mass of the rovers is located near the pivot of the suspension, which allows the rovers to tilt up to 45 degrees. This is a major factor in aiding the mobility of the rovers as compared to using a standard spring suspension system when traversing the uneven and rocky terrain of Mars.
The double-ackerman steering system allows for better control of the rovers when traversing, as the six wheels of the rovers make it hard for a single steering system to turn the whole rover, while the double-ackerman system steers both the front and back wheels, allowing for greater turning control of the rovers.
The mounted camera pairs located at the front and back of the rovers are also essential in aiding the mobility of the rovers for hazard detection. This is another important factor as even though the rovers can stay stable while traversing, if they do not have the means to avoid obstacles, it would be all for naught in a collision. Therefore, this makes the front and back-mounted camera pairs essential in aiding the mobility of the rovers.
However, even with all the features of the rovers, from the article "Exploration of Extreme Environments with Current and Emerging Robot Systems"(Kalita et al., 2020), Spirit was stuck for an extended time due to being caught in loose soil, as the wheels could not get any traction.
In conclusion, the mobility system of NASA rovers Spirit and Opportunity allowed for the success in the mission of exploring the surface of Mars due to the features that were added to the rovers.
References
Tunstel, E., Maimone, M., Trebi-Ollennu, A., Yen, J., Petras, R., & Wilson, R. (2005). Mars exploration rover mobility and robotic arm operational performance. NASA.
https://www-robotics.jpl.nasa.gov/publications/Mark_Maimone/MobIDDPerf90sols.pdf
Lindemann, R., Bickler, D., Harrington, B., Ortiz, G. & Voorhees, C. (2006). Mars Exploration Rover Mobility Development. IEEE Robotics & Automation Magazine.
https://ieeexplore.ieee.org.singaporetech.remotexs.co/stamp/stamp.jsp?tp=&arnumber=1638012&tag=1
Kalita, H., Thangavelautham, J. Exploration of Extreme Environments with Current and Emerging Robot Systems. Curr Robot Rep 1, 97–104 (2020).
Comments
Post a Comment