How a planetary rover drives around rocks

Radio signals take minutes to reach another planet, so a rover cannot be steered live. Instead it stops, takes stereo image pairs, builds a 3D map of nearby rocks and slopes, scores possible arcs for safety and progress toward the goal, then drives a short segment and repeats. Because thinking time is long compared with driving time, the pause, not the wheel speed, usually limits how far it travels.

Controls

Labels

Animation speed

Wheel drive speed

Segment length per step

Imaging and planning pause

Step through it

Look in stereoTwo cameras a few centimeters apart see each rock from slightly different angles. Matching points between the pair gives distance, so the rover builds a 3D map of the ground ahead.
Score the arcsOnboard software marks rocks, steps and steep slopes as hazards, then scores a fan of possible arcs for safety and progress toward the goal. It picks the best one.
Drive a short stepThe wheels turn for one segment only, often under a meter, at a few centimeters per second. Then the rover stops and looks again.
Faster wheels barely helpPush the wheel speed to 5 cm/s. With a 70 s pause, the average rate rises only a little, because most of each cycle is spent thinking.
Longer steps on easy groundOn open, flat terrain operators can allow longer segments. At 2 m per step the same pause is spread over twice the distance and the distance per sol climbs.

The traverse rate formula

Each cycle has a driving part and a pause. Driving one segment of length L at wheel speed v takes L divided by v. Add the pause p for imaging and planning, and the average rate is L divided by (L / v + p).

Distance per sol multiplies that rate by the hours the team allots to driving. This model assumes a 4 hour window and ignores slip, turning in place, and time spent on visual odometry, so it is a simplified planning estimate. Published results from early Mars rover missions report wheel speeds of a few centimeters per second and net autonomous rates well under 1 cm/s once thinking time is included.

Try it: set the pause to 150 s and the segment to 0.35 m. The wheels turn less than a tenth of the time and the rover covers only a few tens of meters per sol. Then cut the pause to 10 s and watch the rate jump.

Why not just drive blind?

When the ground ahead is visible in orbital or earlier images and looks safe, teams often command blind drives that skip the stops and run much faster. Autonomous hazard avoidance is used where the terrain is unknown or the route goes beyond what the team could see, trading speed for safety.

Where Avid uses this

Avid's agricultural robotics and HydroVzn autonomous drone work rely on the same see, plan, act loop: sense the ground, pick a safe path, move, and sense again.

Sources

Autonomous Navigation Results from the Mars Exploration Rover (MER) MissionNASA Jet Propulsion Laboratory, Robotics Section
Improved Path Planning Onboard the Mars Exploration RoversNASA Technical Reports Server
Autonomous Rover Traverse and Precise Arm Placement on Remotely Designated TargetsCarnegie Mellon University, Robotics Institute (with NASA JPL)

How to cite this model

Avid Solutions International. (2026, November 11). How a planetary rover drives around rocks [Interactive 3D model]. Avid Field Lab. https://avidsolutionsintl.com/explore/rover-hazard-avoidance

Last updated November 11, 2026

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