Team2890/allwpilib
4
0
Fork 0
mirror of https://github.com/wpilibsuite/allwpilib synced 2026-06-25 01:41:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

[wpimath] Fix ElevatorSim::GetCurrentDraw() in C++ (#8370)

Browse Source 
The Kv calculation in C++ was missing a negative sign compared to the Java implementation.
This commit is contained in:
Benjamin Hall
2025-11-13 13:48:43 -05:00
committed by GitHub
parent b8d6bc2eb1
commit 5f63c59796
3 changed files with 25 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
wpilibc/src/main/native/cpp/simulation/ElevatorSim.cpp
View File

@@ -88,7 +88,7 @@ units::ampere_t ElevatorSim::GetCurrentDraw() const {
double kA = 1.0 / m_plant.B(1, 0);
using Kv_t = units::unit_t<units::compound_unit<
units::volt, units::inverse<units::meters_per_second>>>;
Kv_t Kv = Kv_t{kA * m_plant.A(1, 1)};
Kv_t Kv = Kv_t{-kA * m_plant.A(1, 1)};
units::meters_per_second_t velocity{m_x(1)};
units::radians_per_second_t motorVelocity = velocity * Kv * m_gearbox.Kv;

12
wpilibc/src/test/native/cpp/simulation/ElevatorSimTest.cpp
View File

@@ -92,3 +92,15 @@ TEST(ElevatorSimTest, Stability) {
frc::Vectord<1>{12.0}, 20_ms * 50)(0)},
sim.GetPosition(), 1_cm);
}
TEST(ElevatorSimTest, CurrentDraw) {
auto const motor = frc::DCMotor::KrakenX60(2);
frc::sim::ElevatorSim sim(motor, 20, 8_kg, 0.1_m, 0_m, 1_m, true, 0_m,
{0.01, 0.0});
EXPECT_DOUBLE_EQ(0.0, sim.GetCurrentDraw().value());
sim.SetInputVoltage(motor.Voltage(motor.Torque(60_A), 0_rad_per_s));
sim.Update(100_ms);
// current draw should start at 60 A and decrease as the back emf catches up
EXPECT_TRUE(0_A < sim.GetCurrentDraw() && sim.GetCurrentDraw() < 60_A);
}

12
wpilibj/src/test/java/edu/wpi/first/wpilibj/simulation/ElevatorSimTest.java
View File

@@ -124,4 +124,16 @@ class ElevatorSimTest {
sim.getPositionMeters(),
0.01);
}
@Test
void testCurrentDraw() {
var motor = DCMotor.getKrakenX60(2);
var sim = new ElevatorSim(motor, 20, 8.0, 0.1, 0.0, 1.0, true, 0.0, 0.01, 0.0);
assertEquals(0.0, sim.getCurrentDrawAmps());
sim.setInputVoltage(motor.getVoltage(motor.getTorque(60.0), 0.0));
sim.update(0.100);
// current draw should start at 60 A and decrease as the back emf catches up
assertTrue(0.0 < sim.getCurrentDrawAmps() && sim.getCurrentDrawAmps() < 60.0);
}
}