Interactive tools for robot kinematics, control, and motion planning.https://devol.dev/https://devol.dev/posts/differential-drive/https://devol.dev/posts/differential-drive/Two wheels, two motors, and the one equation underneath skid steer, Ackermann steering and every trailer that ever jackknifed.Mon, 10 Aug 2026 00:00:00 GMThttps://devol.dev/posts/configuration-space/https://devol.dev/posts/configuration-space/Grow every obstacle by the robot's own shape and the robot becomes a point. Every planner after that is simpler.Fri, 07 Aug 2026 00:00:00 GMThttps://devol.dev/posts/mecanum-drive/https://devol.dev/posts/mecanum-drive/Drive a mecanum chassis, watch the four motor powers, and find out why mounting the rollers wrong costs a whole degree of freedom.Wed, 05 Aug 2026 00:00:00 GMThttps://devol.dev/posts/a-star-search/https://devol.dev/posts/a-star-search/Dijkstra plus an estimate of the distance remaining, and far less of the map examined.Tue, 04 Aug 2026 00:00:00 GMThttps://devol.dev/posts/breadth-first-search/https://devol.dev/posts/breadth-first-search/Every cell one step away, then every cell two steps away. The first route it finds is the shortest.Tue, 04 Aug 2026 00:00:00 GMThttps://devol.dev/posts/depth-first-search/https://devol.dev/posts/depth-first-search/Change the queue to a stack and every guarantee disappears.Tue, 04 Aug 2026 00:00:00 GMThttps://devol.dev/posts/perceptron/https://devol.dev/posts/perceptron/One neuron computes a weighted sum and thresholds it, which draws one straight line. Everything else follows from what that line cannot do.Tue, 04 Aug 2026 00:00:00 GMThttps://devol.dev/posts/dh-parameters/https://devol.dev/posts/dh-parameters/Four numbers per joint describe an entire arm. Type a table in and watch it appear.Mon, 03 Aug 2026 00:00:00 GMThttps://devol.dev/posts/gear-ratio-and-what-it-costs/https://devol.dev/posts/gear-ratio-and-what-it-costs/Bigger gears turn slower and push harder. Change the tooth counts and watch the train work it out.Mon, 03 Aug 2026 00:00:00 GMThttps://devol.dev/posts/q-learning-the-table/https://devol.dev/posts/q-learning-the-table/A robot learns to pick and place by filling in a table of numbers, one cell at a time.Mon, 03 Aug 2026 00:00:00 GMThttps://devol.dev/posts/inverse-kinematics-two-ways/https://devol.dev/posts/inverse-kinematics-two-ways/Every reachable point has two arm configurations, and choosing between them is a real decision.Sun, 02 Aug 2026 00:00:00 GMThttps://devol.dev/posts/tuning-a-pid-by-hand/https://devol.dev/posts/tuning-a-pid-by-hand/Three gains, each one a trade. Tune a joint and watch the response change.Sun, 02 Aug 2026 00:00:00 GMT