FEAT added initial support for open-loop motor control

Author: askuric

examples/motion_control/open_loop_motor_control/open_loop_position_example/open_loop_position_example.ino

@@ -0,0 +1,63 @@
+// Open loop motor control example 
+ #include <SimpleFOC.h>
+
+// motor instance
+BLDCMotor motor = BLDCMotor(3, 10, 6, 11, 7);
+
+void setup() {
+  
+  // power supply voltage
+  // default 12V
+  motor.voltage_power_supply = 12;
+
+  // init motor hardware
+  motor.init();
+
+  Serial.begin(115200);
+  Serial.println("Motor ready!");
+  _delay(1000);
+}
+
+float target_position = 0; // rad/s
+float target_velocity= 10; // rad/s
+float target_voltage = 3; // V
+
+void loop() {
+  // set angle in open loop
+  // - angle - rad
+  // - velocity - rad/s
+  // - voltage  - V
+  motor.angleOpenloop(target_position, target_velocity, target_voltage);
+
+  // a bit of delay
+  _delay(1);
+
+  // receive the used commands from serial
+  serialReceiveUserCommand();
+}
+
+// utility function enabling serial communication with the user to set the target values
+// this function can be implemented in serialEvent function as well
+void serialReceiveUserCommand() {
+  
+  // a string to hold incoming data
+  static String received_chars;
+  
+  while (Serial.available()) {
+    // get the new byte:
+    char inChar = (char)Serial.read();
+    // add it to the string buffer:
+    received_chars += inChar;
+    // end of user input
+    if (inChar == '\n') {
+      
+      // change the motor target
+      target_position = received_chars.toFloat();
+      Serial.print("Target position: ");
+      Serial.println(target_position);
+      
+      // reset the command buffer 
+      received_chars = "";
+    }
+  }
+}

examples/motion_control/open_loop_motor_control/open_loop_velocity_example/open_loop_velocity_example.ino

@@ -0,0 +1,60 @@
+// Open loop motor control example 
+ #include <SimpleFOC.h>
+
+// motor instance
+BLDCMotor motor = BLDCMotor(3, 10, 6, 11, 7);
+
+void setup() {
+  
+  // power supply voltage
+  // default 12V
+  motor.voltage_power_supply = 12;
+
+  // init motor hardware
+  motor.init();
+
+  Serial.begin(115200);
+  Serial.println("Motor ready!");
+  _delay(1000);
+}
+
+float target_velocity= 2; // rad/s
+float target_voltage = 3; // V
+void loop() {
+  // set velocity in open loop
+  // - velocity - rad/s
+  // - voltage  - V
+  motor.velocityOpenloop(target_velocity, target_voltage);
+
+  // a bit of delay
+  _delay(1);
+
+  // receive the used commands from serial
+  serialReceiveUserCommand();
+}
+
+// utility function enabling serial communication with the user to set the target values
+// this function can be implemented in serialEvent function as well
+void serialReceiveUserCommand() {
+  
+  // a string to hold incoming data
+  static String received_chars;
+  
+  while (Serial.available()) {
+    // get the new byte:
+    char inChar = (char)Serial.read();
+    // add it to the string buffer:
+    received_chars += inChar;
+    // end of user input
+    if (inChar == '\n') {
+      
+      // change the motor target
+      target_velocity = received_chars.toFloat();
+      Serial.print("Target velocity: ");
+      Serial.println(target_velocity);
+      
+      // reset the command buffer 
+      received_chars = "";
+    }
+  }
+}

examples/utils/open_loop_motor_test/open_loop_motor_test.ino

@@ -46,6 +46,8 @@ initAbsoluteZero	KEYWORD2
 hasAbsoluteZero	KEYWORD2
 needsAbsoluteZeroSearch	KEYWORD2
 useMonitoring	KEYWORD2
+angleOpenloop	KEYWORD2
+velocityOpenloop	KEYWORD2
 
 voltage_q	KEYWORD2
 shaft_angle_sp	KEYWORD2

keywords.txt

@@ -612,4 +612,36 @@ int BLDCMotor::command(String user_command) {
   }
   // return 0 if error and 1 if ok
   return errorFlag;
+}
+
+
+// set velocity in open loop
+// - velocity - rad/s
+// - voltage  - V
+void BLDCMotor::velocityOpenloop(float vel, float voltage){
+  float Ts = (_micros() - open_loop_timestamp) * 1e-6;
+
+  shaft_angle += vel*Ts; 
+
+  setPhaseVoltage(voltage, electricAngle(shaft_angle));
+
+  open_loop_timestamp = _micros();
+}
+
+// set angle in open loop
+// - angle - rad
+// - velocity - rad/s
+// - voltage  - V
+void BLDCMotor::angleOpenloop(float angle, float vel, float voltage){
+  float Ts = (_micros() - open_loop_timestamp) * 1e-6;
+
+  if(abs(angle- shaft_angle) > abs(vel*Ts)){
+    shaft_angle += _sign(angle - shaft_angle) * abs(vel)*Ts; 
+  }else{
+    shaft_angle = angle;
+  }
+
+  setPhaseVoltage(voltage, electricAngle(shaft_angle));
+
+  open_loop_timestamp = _micros();
 }

src/BLDCMotor.cpp

@@ -20,7 +20,7 @@
 enum ControlType{
   voltage,//!< Torque control using voltage
   velocity,//!< Velocity motion control
-  angle//!< Position/angle motion control
+  angle,//!< Position/angle motion control
 };
 
 /**
@@ -121,7 +121,17 @@ class BLDCMotor
      * This function doesn't need to be run upon each loop execution - depends of the use case
      */
     void move(float target = NOT_SET);
+
+    // set velocity in open loop
+    // - velocity - rad/s
+    // - voltage  - V
+    void velocityOpenloop(float vel, float voltage);
 
+    // set angle in open loop
+    // - angle - rad
+    // - velocity - rad/s
+    // - voltage  - V
+    void angleOpenloop(float angle, float vel, float voltage);
 
     // hardware variables
   	int pwmA; //!< phase A pwm pin number
@@ -284,6 +294,10 @@ class BLDCMotor
     // phase voltages 
     float	Ualpha,Ubeta; //!< Phase voltages U alpha and U beta used for inverse Park and Clarke transform
 
+
+    // open loop variables
+    long open_loop_timestamp;
+
 };
 
 

src/BLDCMotor.h

@@ -13,7 +13,7 @@
 #endif
 
 // sign function
-#define sign(a) ( ( (a) < 0 )  ?  -1   : ( (a) > 0 ) )
+#define _sign(a) ( ( (a) < 0 )  ?  -1   : ( (a) > 0 ) )
 #define _round(x) ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))
 
 // utility defines