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-rw-r--r--src/core/lib/transport/pid_controller.c57
-rw-r--r--src/core/lib/transport/pid_controller.h53
2 files changed, 110 insertions, 0 deletions
diff --git a/src/core/lib/transport/pid_controller.c b/src/core/lib/transport/pid_controller.c
new file mode 100644
index 0000000000..a661116916
--- /dev/null
+++ b/src/core/lib/transport/pid_controller.c
@@ -0,0 +1,57 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/transport/pid_controller.h"
+
+void grpc_pid_controller_init(grpc_pid_controller *pid_controller,
+ double gain_p, double gain_i, double gain_d) {
+ pid_controller->gain_p = gain_p;
+ pid_controller->gain_i = gain_i;
+ pid_controller->gain_d = gain_d;
+ grpc_pid_controller_reset(pid_controller);
+}
+
+void grpc_pid_controller_reset(grpc_pid_controller *pid_controller) {
+ pid_controller->last_error = 0.0;
+ pid_controller->error_integral = 0.0;
+}
+
+double grpc_pid_controller_update(grpc_pid_controller *pid_controller,
+ double error, double dt) {
+ pid_controller->error_integral += error * dt;
+ double diff_error = (error - pid_controller->last_error) / dt;
+ pid_controller->last_error = error;
+ return pid_controller->gain_p * error +
+ pid_controller->gain_i * pid_controller->error_integral +
+ pid_controller->gain_d * diff_error;
+}
diff --git a/src/core/lib/transport/pid_controller.h b/src/core/lib/transport/pid_controller.h
new file mode 100644
index 0000000000..aa3d0a77f7
--- /dev/null
+++ b/src/core/lib/transport/pid_controller.h
@@ -0,0 +1,53 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H
+#define GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H
+
+typedef struct {
+ double gain_p;
+ double gain_i;
+ double gain_d;
+ double last_error;
+ double error_integral;
+} grpc_pid_controller;
+
+void grpc_pid_controller_init(grpc_pid_controller *pid_controller,
+ double gain_p, double gain_i, double gain_d);
+
+void grpc_pid_controller_reset(grpc_pid_controller *pid_controller);
+
+double grpc_pid_controller_update(grpc_pid_controller *pid_controller,
+ double error, double dt);
+
+#endif