Wheel Motor - Versionsgeschichte

Pierlau38: /* Motors testing */

2016-01-02T11:17:17Z

‎Motors testing

Pierlau38: /* Motor Methods */

2015-12-24T21:36:33Z

‎Motor Methods

Pierlau38 am 7. Dezember 2015 um 20:48 Uhr

2015-12-07T20:48:51Z

Pierlau38: /* Motor variable */

2015-12-06T19:31:45Z

‎Motor variable

Pierlau38 am 6. Dezember 2015 um 17:52 Uhr

2015-12-06T17:52:31Z

Pierlau38: /* Motor controller (PID) */

2015-12-06T17:33:36Z

‎Motor controller (PID)

Pierlau38: /* Programming */

2015-12-06T17:33:02Z

‎Programming

Pierlau38: /* Wiring */

2015-12-05T22:13:56Z

‎Wiring

Pierlau38 am 5. Dezember 2015 um 22:10 Uhr

2015-12-05T22:10:07Z

Pierlau38: Die Seite wurde neu angelegt: „= Wheel motors caracteristics & driver = File: ardumower_motor.jpg | Ardumower gear motor with encoder (8mm diameter, 5900 rpm motor, 0.055 Nm, gea…“

2015-12-05T22:01:49Z

Die Seite wurde neu angelegt: „= Wheel motors caracteristics & driver = <gallery> File: ardumower_motor.jpg | Ardumower gear motor with encoder (8mm diameter, 5900 rpm motor, 0.055 Nm, gea…“

Neue Seite

= Wheel motors caracteristics & driver =
<gallery>
File: ardumower_motor.jpg | Ardumower gear motor with encoder (8mm diameter, 5900 rpm motor, 0.055 Nm, gear ratio 1/212, output torque 2.45Nm, output rpm 31)
File: magnetic_encoder.PNG | Motor wiring
File: wheel_motor_diagram.png | Ardumower gear motor curve (motor only)
File:decrease_motor_noise.png | Decrease motor noise
</gallery>
The two left and right gear motors are controlled independently (aka 'differential driving') to:

* drive the robot forward/backward
* steer the robot left/right

The Ardumower wheel motor features:
* A rotation speed up to 31 rpm allows to move the robot at sufficient speed (at up to meter/sec = 31rpm/60 * PI * 0.25m = 0.4m/sec using 250mm diameter wheels)
* A high torque (2.45Nm) guarantees that the robot can climb small hills as well (with 2 motors, 0.125 radius wheel, 31rpm = 0.4m/s, acceleration = 0.2 ( 1/2 of nomeinal speed) up to 14 degree) [http://www.robotshop.com/blog/en/drive-motor-sizing-tool-9698 see calculator]
* Integrated encoders, so it can measure the rotation speed, the distance and the direction (see [[Odometry]] for more information) - Encoders are REQUIRED for Ardumower software.
* 24V (load current ~1A)

= Wiring =

One pin controls the direction (forward/backward), the other pin controls the speed. One analog input pin is connected to the current sensor. The current sensor module (ACS712-05A) is connected in series with the motor.

<gallery>
File:Ardumower_motor_driver_circuit.png | NOTE: only for demonstration! See real [http://wiki.ardumower.de/index.php?title=Ardumower_PCB schematics] for concrete wiring
</gallery>

Protection board is advice to be used between controler and motor.

== Control principal : PWM frequency ==
The speed of the motor is controlled by a PWM duty signal. We use the Arduino default PWM frequency (490 Hz) to control the motor drivers.

<gallery>
File: Arduino_pwm.png | Arduino PWM duty signal
File: Pwm_490hz.png | PWM 490 Hz: odometry ticks, sense (current)
File: Pwm_3khz.png | PWM 3.9 Khz: odometry ticks, sense (current)
File: Pwm_20khz.png | PWM 20 Khz: odometry ticks, sense (current)
File: Pwm_31khz.png | PWM 31 Khz: odometry ticks, sense (current)
</gallery>

= Programming =

/!\ work on going !

@@ Zeile 137: / Zeile 137: @@
 Run the serial console (Arduino IDE: CTRL+SHIFT+M, 19200 Baud) and press 'd' and ENTER for menu.
 Then press '1' and ENTER to run the motor test.
 Test consist of the following sequence :
-Left motor : Forward half speed
+* Left motor : Forward half speed
 Left motor : Reverse full speed
-Right motor : Forward half speed
+* Left motor : Reverse full speed
 Right motor : Reverse full speed

@@ Zeile 112: / Zeile 112: @@
 == Motor Methods ==
    void testMotors();
-  void motorControl();
+Then, there are several MotorControl methods according to mower state :
-   void setMotorPWM(int pwmLeft, int pwmRight, boolean useAccel);
+if current state is 'STATE_PERI_TRACK' then
 = Motors testing =

@@ Zeile 48: / Zeile 48: @@
 = Programming =
-== Motor variable ==
+== Motor variables ==
      // --------- wheel motor state ----------------------------
      // wheel motor speed ( <0 backward, >0 forward); range -motorSpeedMaxRpm..motorSpeedMaxRpm
-     float motorAccel  ;          // motor wheel acceleration (warning: do not set too high)
+    //                                   [Default value]
-     int motorSpeedMaxRpm   ;     // motor wheel max RPM
+     float motorAccel  ;          // motor wheel acceleration - only functional when odometry is not in use
-     int motorSpeedMaxPwm  ;      // motor wheel max Pwm  (8-bit PWM=255, 10-bit PWM=1023)
+                                 // (warning: do not set too high) [1000]
      float motorPowerMax   ;      // motor wheel max power (Watt)
-     PID motorLeftPID;            // motor left wheel PID controller
+     PID motorLeftPID;            // motor left wheel PID controller [Kp=1.5 , Kd=0.29, Ki=0.25]
      PID motorRightPID;           // motor right wheel PID controller
      float motorSenseRightScale ; // motor right sense scale (mA=(ADC-zero)/scale)

@@ Zeile 52: / Zeile 52: @@
      // --------- wheel motor state ----------------------------
      // wheel motor speed ( <0 backward, >0 forward); range -motorSpeedMaxRpm..motorSpeedMaxRpm
-     float motorAccel  ;  // motor wheel acceleration (warning: do not set too high)
+     float motorAccel  ;          // motor wheel acceleration (warning: do not set too high)
-     int motorSpeedMaxRpm   ;   // motor wheel max RPM
+     int motorSpeedMaxRpm   ;     // motor wheel max RPM
-     int motorSpeedMaxPwm  ;  // motor wheel max Pwm  (8-bit PWM=255, 10-bit PWM=1023)
+     int motorSpeedMaxPwm  ;      // motor wheel max Pwm  (8-bit PWM=255, 10-bit PWM=1023)
-     float motorPowerMax   ;    // motor wheel max power (Watt)
+     float motorPowerMax   ;      // motor wheel max power (Watt)
-     PID motorLeftPID;              // motor left wheel PID controller
+     PID motorLeftPID;            // motor left wheel PID controller
-     PID motorRightPID;              // motor right wheel PID controller
+     PID motorRightPID;           // motor right wheel PID controller
      float motorSenseRightScale ; // motor right sense scale (mA=(ADC-zero)/scale)
-     float motorSenseLeftScale ; // motor left sense scale  (mA=(ADC-zero)/scale)
+     float motorSenseLeftScale ;  // motor left sense scale  (mA=(ADC-zero)/scale)
-     int motorRollTimeMax ;  // max. roll time (ms)
+     int motorRollTimeMax ;       // max. roll time (ms)
-     int motorRollTimeMin  ; // min. roll time (ms)
+     int motorRollTimeMin  ;      // min. roll time (ms)
-     int motorReverseTime ;  // max. reverse time (ms)
+     int motorReverseTime ;       // max. reverse time (ms)
-     long motorForwTimeMax; // max. forward time (ms) / timeout
+     long motorForwTimeMax;       // max. forward time (ms) / timeout
-     float motorBiDirSpeedRatio1 ;   // bidir mow pattern speed ratio 1
+     float motorBiDirSpeedRatio1 ;// bidir mow pattern speed ratio 1
-     float motorBiDirSpeedRatio2 ;   // bidir mow pattern speed ratio 2
+     float motorBiDirSpeedRatio2 ;// bidir mow pattern speed ratio 2
-     bool motorRightSwapDir     ;    // inverse right motor direction?
+     bool motorRightSwapDir     ; // inverse right motor direction?
-     bool motorLeftSwapDir      ;    // inverse left motor direction?
+     bool motorLeftSwapDir      ; // inverse left motor direction?
-     int motorLeftSpeedRpmSet ; // set speed
+     int motorLeftSpeedRpmSet ;   // set speed
      int motorRightSpeedRpmSet ;
-     float motorLeftPWMCurr ; // current speed
+     float motorLeftPWMCurr ;     // current speed
      float motorRightPWMCurr ;
      int motorRightSenseADC ;
@@ Zeile 76: / Zeile 76: @@
      float motorLeftSenseCurrent ;
      float motorRightSenseCurrent ;
-     float motorLeftSense ;      // motor power (range 0..MAX_MOTOR_POWER)
+     float motorLeftSense ;       // motor power (range 0..MAX_MOTOR_POWER)
      float motorRightSense ;
      int motorPowerIgnoreTime;
@@ Zeile 88: / Zeile 88: @@
      boolean rotateLeft;
      unsigned long nextTimeRotationChange;

← Nächstältere Version		Version vom 6. Dezember 2015, 17:33 Uhr
Zeile 47:		Zeile 47:
	= Programming =		= Programming =

−	/~~!\ work on going !~~	+	== Motor variable ==
		+
		+	// --------- wheel motor state ----------------------------
		+	// wheel motor speed ( <0 backward, >0 forward); range -motorSpeedMaxRpm..motorSpeedMaxRpm
		+	float motorAccel ; // motor wheel acceleration (warning: do not set too high)
		+	int motorSpeedMaxRpm ; // motor wheel max RPM
		+	int motorSpeedMaxPwm ; // motor wheel max Pwm (8-bit PWM=255, 10-bit PWM=1023)
		+	float motorPowerMax ; // motor wheel max power (Watt)
		+	PID motorLeftPID; // motor left wheel PID controller
		+	PID motorRightPID; // motor right wheel PID controller
		+	float motorSenseRightScale ; // motor right sense scale (mA=(ADC-zero)/scale)
		+	float motorSenseLeftScale ; // motor left sense scale (mA=(ADC-zero)/scale)
		+	int motorRollTimeMax ; // max. roll time (ms)
		+	int motorRollTimeMin ; // min. roll time (ms)
		+	int motorReverseTime ; // max. reverse time (ms)
		+	long motorForwTimeMax; // max. forward time (ms) / timeout
		+	float motorBiDirSpeedRatio1 ; // bidir mow pattern speed ratio 1
		+	float motorBiDirSpeedRatio2 ; // bidir mow pattern speed ratio 2
		+	bool motorRightSwapDir ; // inverse right motor direction?
		+	bool motorLeftSwapDir ; // inverse left motor direction?
		+	int motorLeftSpeedRpmSet ; // set speed
		+	int motorRightSpeedRpmSet ;
		+	float motorLeftPWMCurr ; // current speed
		+	float motorRightPWMCurr ;
		+	int motorRightSenseADC ;
		+	int motorLeftSenseADC ;
		+	float motorLeftSenseCurrent ;
		+	float motorRightSenseCurrent ;
		+	float motorLeftSense ; // motor power (range 0..MAX_MOTOR_POWER)
		+	float motorRightSense ;
		+	int motorPowerIgnoreTime;
		+	int motorZeroSettleTime; // how long (ms) to wait for motor to settle at zero speed
		+	int motorLeftSenseCounter ; // motor current counter
		+	int motorRightSenseCounter ;
		+	unsigned long nextTimeMotorSense ;
		+	unsigned long lastSetMotorSpeedTime;
		+	unsigned long motorLeftZeroTimeout;
		+	unsigned long motorRightZeroTimeout;
		+	boolean rotateLeft;
		+	unsigned long nextTimeRotationChange;

@@ Zeile 19: / Zeile 19: @@
 = Wiring =
-One pin controls the direction (forward/backward), the other pin controls the speed. One analog input pin is connected to the current sensor. The current sensor module (ACS712-05A) is connected in series with the motor.
+Using motor driver MC33926 :
 <gallery>
-File:Ardumower_motor_driver_circuit.png | NOTE: only for demonstration! See real [http://wiki.ardumower.de/index.php?title=Ardumower_PCB schematics] for concrete wiring
+File:MC33926_schematics.jpg | schematics
 </gallery>
 [https://github.com/Ardumower/ardumower/raw/master/pcb/megashield_svn_1.2_geschlossen/Dokumentation/WORKSHOP%20Protector-Board.pdf Protector board] is adviced to be used between controler and motor.
 == Control principal : PWM frequency ==

@@ Zeile 36: / Zeile 36: @@
 File: Pwm_20khz.png | PWM 20 Khz: odometry ticks, sense (current)
 File: Pwm_31khz.png | PWM 31 Khz: odometry ticks, sense (current)
 </gallery>