[wpimath] Check LTV controller max velocity precondition (#5142)

wpimath/src/main/native/cpp/controller/LTVDifferentialDriveController.cpp

@@ -5,6 +5,7 @@
 #include "frc/controller/LTVDifferentialDriveController.h"
 
 #include <cmath>
+#include <stdexcept>
 
 #include "frc/MathUtil.h"
 #include "frc/StateSpaceUtil.h"
@@ -65,6 +66,11 @@ LTVDifferentialDriveController::LTVDifferentialDriveController(
   units::meters_per_second_t maxV{
       -plant.A().householderQr().solve(plant.B() * Vectord<2>{12.0, 12.0})(0)};
 
+  if (maxV <= 0_mps) {
+    throw std::domain_error(
+        "Max velocity of plant with 12 V input must be greater than zero.");
+  }
+
   for (auto velocity = -maxV; velocity < maxV; velocity += 0.01_mps) {
     // The DARE is ill-conditioned if the velocity is close to zero, so don't
     // let the system stop.

wpimath/src/main/native/cpp/controller/LTVUnicycleController.cpp

@@ -4,6 +4,8 @@
 
 #include "frc/controller/LTVUnicycleController.h"
 
+#include <stdexcept>
+
 #include "frc/StateSpaceUtil.h"
 #include "frc/controller/LinearQuadraticRegulator.h"
 #include "units/math.h"
@@ -37,6 +39,10 @@ LTVUnicycleController::LTVUnicycleController(
 LTVUnicycleController::LTVUnicycleController(
     const wpi::array<double, 3>& Qelems, const wpi::array<double, 2>& Relems,
     units::second_t dt, units::meters_per_second_t maxVelocity) {
+  if (maxVelocity <= 0_mps) {
+    throw std::domain_error("Max velocity must be greater than zero.");
+  }
+
   // The change in global pose for a unicycle is defined by the following three
   // equations.
   //