19-06-2012, 04:27 PM
Design and implementation of servo actuator controller for control of mobile robots
[attachment=24840]
SERVO MOTORS :-
Servo motors are DC motors with built in gearing and feedback control loop circuitry.
Servo motors can rotate about 90 to 180 degrees. Some rotate through a full 360 degrees or more.
Since servos are fully self-contained, the velocity and angle control loops are very easy to implement, while prices remain very affordable.
The standard voltage is 4.8 V DC, however 6 V and 12V has also been seen for a few servos.
CONTROL METHOD :-
Pulse width modulation (PWM)
The general concept is to simply send an ordinary logic square wave to your servo at a specific wave length, and the servo goes to a particular angle (or velocity if the servo is modified). The wavelength directly maps to servo angle.
The control signal is a digital PWM signal with a 50 Hz frame rate.
The pulse nominally ranges from 1.0 ms to 2.0 ms with 1.5 ms always being center of range.
The servo is controlled by three wires: ground, power, and control.
APPLICATIONS :-
Robotics
Steering Mechanisms
Hydraulics
To govern the speed of waterwheels
[attachment=24840]
SERVO MOTORS :-
Servo motors are DC motors with built in gearing and feedback control loop circuitry.
Servo motors can rotate about 90 to 180 degrees. Some rotate through a full 360 degrees or more.
Since servos are fully self-contained, the velocity and angle control loops are very easy to implement, while prices remain very affordable.
The standard voltage is 4.8 V DC, however 6 V and 12V has also been seen for a few servos.
CONTROL METHOD :-
Pulse width modulation (PWM)
The general concept is to simply send an ordinary logic square wave to your servo at a specific wave length, and the servo goes to a particular angle (or velocity if the servo is modified). The wavelength directly maps to servo angle.
The control signal is a digital PWM signal with a 50 Hz frame rate.
The pulse nominally ranges from 1.0 ms to 2.0 ms with 1.5 ms always being center of range.
The servo is controlled by three wires: ground, power, and control.
APPLICATIONS :-
Robotics
Steering Mechanisms
Hydraulics
To govern the speed of waterwheels