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Speaking of general motors, stepper motors, servo motors refer to the DC micro-motor, usually we come into contact also with the majority DC. Motor deep knowledge, this is only for beginners an idea of making the robot used various motors.
Motors, commonly known as "motor", according to law of electromagnetic induction means to achieve an electromagnetic transmitting means, or electrical energy conversion. Also known as the motor (known as a motor), in the circuit by the letter "M" represents (with the old standard "D"). Its main role is to produce a driving torque, as a power source for various mechanical or electrical generator in the circuit by the letter "G" represents.
Ordinary DC
General Motors is more of our time flat motors, electric toys, razors, etc. which are. Usually only two pins, with a battery connected to the positive and negative two pins will turn up, and then the battery negative to positive then the motor will then reverse in the reverse rotation on the two pins. This motor has a speed too fast, too small torque characteristics are generally not used directly in the smart cart.
Geared Motor
General Motors gear motor is coupled with a gear box, thus reducing the speed, increased torque, so that General Motors and some more extensive use of space.
Geared motors are generally smart small car, and for controlling the motor are generally used H-bridge program , L298 chip is this principle.
While the speed is generally used PWM (Pulse Width Modulation) scheme, using a single-chip timer control waveform generating variable duty cycle PWM wave or of different sizes to control the PWM output hardware directly trolley overall speed.
Stepper motor
Stepper motor is an electrical pulse signal into angular or linear displacement open loop control of the stepping motor element member. In the case of non overload, the motor speed and stopping location depends only on the frequency and number of the pulse signal, without being affected by changes in load, when the stepping driver receives a pulse signal, it drives the stepping motor by the rotational direction is set to a fixed angle, referred to as "step angle", its rotation in a fixed angle operation step by step. It can be controlled by controlling the number of pulses the angular displacement, so as to achieve accurate positioning purposes; the same velocity and acceleration can be controlled by controlling the pulse motor rotation frequency, so as to achieve speed control.
Steering gear and servo motors
Steering gear is mainly constituted by a housing, a circuit board, a coreless motor, a gear position detector. Its working principle is sent to the servo signals by the receiver, the rotational direction is determined via the IC circuit board, and then drive coreless motor starts to rotate, the power transmitted through the reduction gear arm, while the return signal from the position detector to determine whether positioning has been reached. The position detector is actually a variable resistor, the resistance value when the steering rotates will change, by detecting the resistance value of the rotation angle would be seen.
Servo information on specifications provided by the manufacturer, will be included Dimensions (mm), torque (kg / cm), speed (sec / 60 °), a test voltage (V) and weight (g) and other basic information. Torsion units are kg / cm, meaning that the length of the arm 1 centimeters, a few kilograms can lift heavy objects. This is the concept of the arm, so the longer arm length, the smaller the torque. Speed unit is sec / 60 °, meaning that the servo 60 ° rotation time required.
Servo motor, also known as force motor, the automatic control system, as the actuator, to convert signals received from the angular displacement or an angular velocity output of the motor shaft. DC and AC servo motor is divided into two categories, the main feature is the voltage zero signal when no rotation phenomena, with increasing rotational speed and torque of uniform decline.
Servo mainly by pulse positioning, substantially can be understood, the servo motor receives a pulse, the pulse will correspond to a rotation angle, thereby achieving displacement, because the servo motor itself includes issuing a pulse, so that a rotation angle of each servo motor, a corresponding number of pulses will be issued, so that, servo motor and a pulse forming received echo, or called closed loop, this way, the system knows the number of pulses sent to the servo motor, while the number of pulses received back, so that it can be rotated very precise control of the motor, to achieve an accurate positioning can be achieved 0.001mm.
DC servo motors are brush and brushless motors. Brush motor is low cost, simple structure, a large starting torque, wide speed range, the control is easy, requiring maintenance, but it is not convenient to maintain (replace the brushes), electromagnetic interference, there are demands on the environment. So it can be used in cost-sensitive general industrial and civil applications.
