Path-tracking control of an autonomous 4WS4WD electric vehicle using driving motors' dynamics

Path-Tracking Control of an Autonomous 4WS4WD Electric Vehicle Using Its Natural Feedback Loops

“…Ploeg et al [11], [12] decompose the problem of PTC of the vehicle into one where each wheel subsystem needs to track its own reference path, assign a model of the formẋ = f (x, u) and y = h(x, u) to each wheel subsystem, design controllers involving feedback linearization, and use Kalman filters to estimate the states of the wheel subsystems from the sensed states of the vehicle body. Controllers that do not use such sophisticated math are possible, as shown in [16] and [17]. The latter work shows that an examination of the natural feedback loops in the vehicle model helps develop a PTC solution that does not use any state observers, and has only three proportional-integralderivative (PID) controllers to tune.…”

“…The contribution of the line of research started in [16] and [17], and continued in this brief is the block diagrammatic representation of the vehicle model along with two novel and useful insights derived from this representation. The first insight helps develop a mathematically simple path-tracking controller, which additionally promises to be simple to tune in practice, using a model that has been treated by earlier authors only asẋ = f (x, u), y = h(x, u) and based on which mathematically sophisticated controllers were developed.…”

“…This brief presents simulation results that help examine the performance of the PTC solution in more detail than presented in [16] and [17], and explains the above-mentioned wheel acceleration constraint through discussions and simulations.…”