From e4c392d4d9a36921c40a8ddabf91085c9cc936b0 Mon Sep 17 00:00:00 2001
From: Andru Liu <90433630+WallabyLester@users.noreply.github.com>
Date: Tue, 8 Oct 2024 18:22:21 -0700
Subject: [PATCH] Added tests for aPID controller.

---
 CPP_Implementation/apid_controller_test.cpp | 100 ++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 CPP_Implementation/apid_controller_test.cpp

diff --git a/CPP_Implementation/apid_controller_test.cpp b/CPP_Implementation/apid_controller_test.cpp
new file mode 100644
index 0000000..1869de7
--- /dev/null
+++ b/CPP_Implementation/apid_controller_test.cpp
@@ -0,0 +1,100 @@
+#include "gtest/gtest.h"
+#include "apid_controller.h"
+
+// Test fixture for aPIDController
+class aPIDControllerTest : public ::testing::Test {
+protected:
+    aPIDController* apid;
+
+    void SetUp() override {
+        apid = new aPIDController(1.0, 0.1, 0.01, 0.1);
+    }
+
+    void TearDown() override {
+        delete apid; 
+    }
+};
+
+// Test case for control signal with zero error
+TEST_F(aPIDControllerTest, Control_Signal_With_Zero_Error) {
+    double target = 1.0;
+    double measured_value = 1.0;
+
+    double control_signal = apid->update(target, measured_value);
+    EXPECT_NEAR(control_signal, 0.0, 1e-5); 
+}
+
+// Test case for control signal with positive error
+TEST_F(aPIDControllerTest, Control_Signal_With_Positive_Error) {
+    double target = 10.0;
+    double measured_value = 5.0;
+
+    double control_signal = apid->update(target, measured_value);
+    EXPECT_GT(control_signal, 0.0);
+}
+
+// Test case for control signal with negative error
+TEST_F(aPIDControllerTest, Control_Signal_With_Negative_Error) {
+    double target = 5.0;
+    double measured_value = 10.0;
+
+    double control_signal = apid->update(target, measured_value);
+    EXPECT_LT(control_signal, 0.0);
+}
+
+// Test case for proportional action
+TEST_F(aPIDControllerTest, Proportional_Action) {
+    double Kp = 2.0;
+    apid->set_Kp(Kp);
+    apid->set_Ki(0.0);
+    apid->set_Kd(0.0);
+    double target = 10.0;
+    
+    double measured_value = 5.0;
+    double control_signal_pos = apid->update(target, measured_value);
+    EXPECT_NEAR(control_signal_pos, Kp * (target - measured_value), 1e-5); 
+
+    measured_value = 15.0;
+    double control_signal_neg = apid->update(target, measured_value);
+    EXPECT_NEAR(control_signal_neg, Kp * (target - measured_value), 1e-5);
+}
+
+// Test case for integral action
+TEST_F(aPIDControllerTest, Integral_Action) {
+    double Kp = 4.0, Ki = 2.0;
+    apid->set_Kp(Kp);
+    apid->set_Ki(Ki);
+    double target = 10.0;
+    double measured_value = 0.0;
+    double dt = 0.1;
+
+    for (int i = 0; i < 10; ++i) {
+        double control_signal = apid->update(target, measured_value);
+        measured_value += (control_signal - measured_value) * dt; 
+    }
+
+    EXPECT_NEAR(measured_value, target, 1.0); 
+}
+
+// Test case for derivative action
+TEST_F(aPIDControllerTest, Derivative_Action) {
+    double Kd = 1.0;
+    apid->set_Kp(0.0);
+    apid->set_Ki(0.0);
+    apid->set_Kd(Kd);
+    double target = 10.0;
+
+    double measured_value = 5.0; 
+    apid->update(target, measured_value);
+
+    measured_value = 15.0; 
+    double controlSignal = apid->update(target, measured_value);
+
+    double expectedDerivative = (target - measured_value)/0.1 - (target - 5.0)/0.1; 
+    EXPECT_NEAR(controlSignal, Kd * expectedDerivative, 1e-5); 
+}
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}