[wpilib] Clamp sim battery voltage to 0 (wpilibsuite#7325)

PeterJohnson · Nov 3, 2024 · debb521 · debb521
1 parent 23e71e1
commit debb521
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/wpilibc/src/main/native/include/frc/simulation/BatterySim.h b/wpilibc/src/main/native/include/frc/simulation/BatterySim.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <algorithm>
 #include <numeric>
 #include <span>
 
@@ -33,8 +34,9 @@ class BatterySim {
   static units::volt_t Calculate(units::volt_t nominalVoltage,
                                  units::ohm_t resistance,
                                  std::span<const units::ampere_t> currents) {
-    return nominalVoltage -
-           std::accumulate(currents.begin(), currents.end(), 0_A) * resistance;
+    return std::max(0_V, nominalVoltage - std::accumulate(currents.begin(),
+                                                          currents.end(), 0_A) *
+                                              resistance);
   }
 
   /**
@@ -52,8 +54,9 @@ class BatterySim {
   static units::volt_t Calculate(
       units::volt_t nominalVoltage, units::ohm_t resistance,
       std::initializer_list<units::ampere_t> currents) {
-    return nominalVoltage -
-           std::accumulate(currents.begin(), currents.end(), 0_A) * resistance;
+    return std::max(0_V, nominalVoltage - std::accumulate(currents.begin(),
+                                                          currents.end(), 0_A) *
+                                              resistance);
   }
 
   /**

diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/simulation/BatterySim.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/simulation/BatterySim.java
@@ -27,7 +27,7 @@ public static double calculateLoadedBatteryVoltage(
     for (var current : currents) {
       retval -= current * resistanceOhms;
     }
-    return retval;
+    return Math.max(0.0, retval);
   }
 
   /**