First of all, the name of "steering gear" is actually a common name, which is the name of those who play model aircraft and ship models, because this kind of motor is often used for rudder surface control. The steering gear is actually a low-end servo motor system, and it is also the most common servo motor system.

The steering gear is a position (angle) servo drive, which is suitable for control systems that require a constantly changing angle and can be maintained. It consists of a lower shell, a control circuit, a motor, a middle shell, a gear set, a bearing and an upper shell. The steering gear is a closed-loop control system. The control circuit board receives the control signal from the signal line and controls the rotation of the motor. The motor drives a series of gear sets, which are decelerated and transmitted to the output rudder plate. The output shaft of the steering gear is connected with the position feedback potentiometer. When the steering wheel rotates, the position feedback potentiometer is driven. The potentiometer will output a voltage signal to the control circuit board for feedback, and then the control circuit board will determine the direction and direction of the motor rotation according to the position. Speed, so as to achieve the target stop.

Types of steering gear

What are the types of steering gear? According to the electronic classification, the steering gear can be divided into analog steering gear and digital steering gear. The analog steering gear adjusts the speed of the motor by simply sending a switch pulse, and the response to small commands is slow, and the motor rotates slowly and quickly. Compared with the traditional analog actuator, the digital actuator can adjust the power of the excitation motor according to the program operation of the microprocessor to adapt to different functional requirements and optimize the performance of the actuator, which can provide higher accuracy and faster response and acceleration effect. According to the signal type can be divided into PWM signal steering gear, RS-485 serial port type steering gear, TTL serial port type steering gear. There are mainly ordinary type, ultra-small, strong type and special purpose type.

1. PWM signal steering gear

Compared with analog communication, which is more resistant to noise, switching from analog signals to PWM signals can greatly extend the communication distance. At the receiving end, through the appropriate RC or LC network, the modulated high-frequency square wave can be filtered out and the signal can be reduced to analog form, so that the analog signal can be controlled digitally. The characteristics of high frequency, high efficiency and high reliability greatly reduce the cost and power consumption.

2. RS-485 serial port type steering gear

Using balanced transmission and differential reception, it has good anti-interference ability, and the signal can be transmitted on kilometers. Multiple steering gears are allowed to be mounted on a bus, and each steering gear on the bus has a unique ID(0~250). The controller accesses a specific steering gear through the steering gear ID, or sends data to all steering gears on the bus through broadcast ID(254). In addition, super ID(253) can be used to send inquiry commands to steering gears on the bus, and steering gears with different IDs can respond in time.

3. TTL Serial Servo

The parallel data transmission mode is better for the data transmission inside the computer processor control device, and the requirement for power supply is not high and the heat loss is also low. In addition, the TTL level signal is directly connected to the integrated circuit without the need for expensive line drivers and receiver circuits.

4. CAN bus steering gear

Using serial asynchronous communication, at the same time can only have a send or receive information, by CAN_H and CAN_L two signal lines, in the form of differential signal communication, strong anti-interference ability. The amplitude of high and low levels is low, and the data transmission speed is relatively high.

Use Scenario

Actuator in the electromechanical system as the basic output actuator, simple control and output makes the single-chip system can easily be docked, its superior angle control performance in the aircraft, submarine model, remote control robot, logistics, robotics, artificial intelligence, automotive and other fields are widely used. For example, in an unmanned aerial vehicle or an aircraft model, the steering gear can control the up and down, left and right rotation of the wing, thereby controlling the flight direction, altitude, etc. In the robot, the steering gear can control the joint movement of the robot, so that the robot can complete a variety of complex actions, such as grasping, shooting, moving and so on.