CN106533278A - Digital steering engine based on coreless motor - Google Patents

Abstract

The invention discloses a digital steering gear based on a hollow cup motor, belonging to the field of remote control model power devices, including a control circuit board (6) and its servo control algorithm module, using a hollow cup motor as power, and optimizing the control algorithm. and torque are significantly improved. The control circuit board (6) collects the current position of the steering wheel measured by the rotary potentiometer (7), and after comparing with the input position and signal processing, the drive circuit outputs the driving signal of the coreless motor (8), and passes through the reducer (3 ), drive the output shaft (4) to rotate until the rudder surface reaches the input position. Thus forming a closed-loop control. Adjust the position of the steering wheel in real time according to the input signal. The present invention makes full use of the characteristics of the hollow cup motor, and effectively improves the rotational speed and torque of the steering gear compared with steering gears of the same level, so that the steering gear can be applied to more complex application scenarios.

Description

A Digital Steering Gear Based on Coreless Motor

technical field

The invention relates to the field of remote control model power devices, in particular to a digital steering gear based on a hollow cup motor.

Background technique

At present, in ordinary steering gears, brushless DC motors or ordinary DC motors are used as power, which cannot solve the contradiction between the volume of the steering gear and the torque speed. Most of the circuit boards are placed at the bottom of the servo, which is not conducive to the development of the servo in the direction of small and large torque. Common servo control methods include digital and analog. In addition, the present invention adds a signal line to enhance the interaction between the steering gear and the host computer.

Contents of the invention

On the basis of the current steering gear development, the present invention proposes a digital steering gear based on a coreless motor. Compared with steering gears of the same level, the speed is faster and the torque is larger.

In order to achieve the above purpose, the following technical solutions can be adopted to achieve it. A digital steering gear based on a coreless motor includes a control circuit board and its servo control algorithm module. The control circuit board collects the current steering wheel measured by the rotary potentiometer. Position, after comparing with the input position and signal processing, output the drive signal of the hollow cup motor through the drive circuit, and drive the output shaft to rotate through the reducer until the rudder surface reaches the input position, thus forming a closed-loop control and adjusting the position of the rudder plate in real time according to the input signal .

Furthermore, the output gear, the final stage gear of the reducer and the rotary potentiometer are coaxially connected through the output shaft to ensure the real-time performance of position feedback. The axis is limited by 0-180 degrees.

Further, the overall size of the control circuit board is controlled at 10mm*12mm*3mm, placed sideways between the second shell and the third shell, close to the motor, and insulated and fixed with insulating double-sided adhesive tape, the control circuit board is STC15W series The single-chip microcomputer is the core, with A/D conversion, clock circuit and PWM output module. The control circuit also includes a voltage-stabilizing output circuit and a power drive circuit, thus forming a complete signal processing and power drive, and realizing motor position servo control.

Further, the reducer includes 5-stage reduction gears with a reduction ratio as high as 1:320.

Further, the wire hole is on the side of the third housing, and there are 4 wires connecting the internal circuit and the external drive circuit, including two power wires, one signal wire, and one feedback wire. The power supply is 5V, and the feedback wire outputs the current position signal.

Furthermore, the coreless motor adopts 716 ultra-high-speed coreless motor, the maximum speed is about 55000RPM, and the maximum locked-rotor current is up to 2A. The notable features are ultra-high speed and super power.

Principle of the present invention is:

It can basically be divided into three processes: sampling-signal processing-driving the motor, such a repeated cycle process. The control circuit collects the current position of the steering wheel measured by the rotary potentiometer, and after comparing with the input position and signal processing, the driving circuit outputs the driving signal of the hollow cup motor, and through the reducer, the output shaft is driven to rotate until the steering surface reaches the input position. Thus forming a closed-loop control. Adjust the position of the steering wheel in real time according to the input signal. On the basis of the above, the motor adopts a coreless motor, and the corresponding power drive circuit is designed to optimize the closed-loop algorithm.

The advantage of the present invention compared with prior art is:

(1) The present invention makes full use of the characteristics of the coreless motor. Compared with steering gears of the same level, the rotational speed and torque of the steering gear are effectively improved, so that the steering gear can be applied to more complex application scenarios.

(2) The size of the hollow cup motor used in the present invention is 7mm*16mm, and the circuit board is clamped in the gap between the motor and the point device. Compared with the steering gear of the same level, the space is greatly saved.

(3), there is a signal feedback in the interface of the present invention, that is, the output of the position of the rudder surface, which is convenient for the monitoring and error reporting of the upper computer.

Description of drawings

Fig. 1 is a schematic diagram of a digital steering gear based on a coreless motor according to the present invention.

Fig. 2 is a functional block diagram of the control circuit of the present invention.

Fig. 3 is a flow chart of the position servo algorithm in the present invention.

The meanings of reference signs in the figure are: 1 is the first housing, 2 is the fixing hole, 3 is the reducer, 4 is the output shaft, 5 is the second housing, 6 is the control circuit board, 7 is the rotary potentiometer, 8 is hollow Cup motor, 9 is a line hole, 10 is a third shell, 11 is an output gear, 12 is a metal rod, and 13 is a cast body.

detailed description

In order to better understand the technical solution of the present invention, a further detailed description will be made below in conjunction with the accompanying drawings.

As shown in Figure 1, a digital steering gear based on a coreless motor includes a circuit board and its servo control algorithm module, the control circuit board 6 collects the current position of the steering wheel measured by the rotary potentiometer 7, and passes the input position After comparison and signal processing, the driving signal of the coreless motor 8 is output through the driving circuit, and the output shaft 4 is driven to rotate through the reducer 3 until the rudder surface reaches the input position. Thus forming a closed-loop control. Adjust the position of the steering wheel in real time according to the input signal.

As shown in schematic diagram 1, the output gear 11 is coaxially connected with the last stage gear of the reducer 3 and the rotary potentiometer 7 through the output shaft 4 . Ensure the real-time performance of position feedback. The cast body 13 on the second housing 5 cooperates with the metal rod 12 on the last gear of the reducer 3 to limit the output shaft by 0-180 degrees.

The overall size of the control circuit board 6 is controlled at 10mm*12mm*3mm, placed sideways between the second shell 5 and the third shell 6, close to the motor, and insulated and fixed with insulating double-sided adhesive tape between them. The control circuit takes the STC15W series microcontroller as the core, with A/D conversion, clock circuit and PWM output module. The control circuit also includes a voltage stabilizing output circuit and a power driving circuit. In this way, complete signal processing and power drive are formed to realize servo control of motor position.

Reducer 3 includes 5-stage reduction gears with a reduction ratio as high as 1:320.

The wire hole 9 is on the side of the third housing 10, and there are 4 wires connecting the internal circuit and the external driving circuit. Including two power cables, one signal cable and one feedback cable. The power supply is 5V, and the feedback line outputs the current position signal.

Coreless motor 8 adopts 716 ultra-high-speed coreless motor, the maximum speed is about 55000RPM, and the maximum locked-rotor current is 2A. Notable features are ultra-high speed, super power.

The specific implementation steps are as follows:

The control circuit is responsible for collecting, receiving and processing signals, and outputs the power supply voltage of the rotary potentiometer 7 at 2.5V±0.1V through the voltage stabilizing circuit. The signal terminal of the rotary potentiometer 7 is sampled and A/D converted into a digital signal PT (target position). Read the received PWM signal to get PN (current given position). The driving pulse width pwm _(k) = kp(PT _(k) -PN)+ki(PT _(k) -PN)/n+kd(PT _(k-1) -PN) is obtained through algorithm processing; the driving circuit drives the motor , through the reducer to the output shaft until PT=PN.

It should be noted that the output shaft 4 and the rotary potentiometer 7 are coaxially installed with the output shaft and the output gear, and the last gear of the reducer 3 is outside the support body, and there is a shaft as long as the second casing 5, which is matched with the second casing 5. The casting body limits the output shaft. The second shell 5 is a semi-closed box body, and the upper surface needs a bearing installation hole and a through hole. There is a colloid connection with a special structure between the output shaft 4 and the output shaft of the potentiometer.

The circuit design block diagram is shown in Figure 2. The circuit design includes 6 parts, including signal processing circuit, clock circuit, power drive circuit, voltage regulator circuit, signal conditioning circuit and communication circuit. The signal processing circuit is based on the STC15W408 single-chip microcomputer; the power drive circuit is based on the motor drive chip LG9110, and the two-way PWM of the single-chip microcomputer provides the driving signal; the RS232 circuit is not integrated on the circuit board, and the program is programmed in advance; the signal conditioning circuit is mainly filtered and passed through the single-chip microcomputer Internal 8-channel A/D conversion is used to collect signals; the voltage regulator circuit provides 2.5V±0.1V voltage signal for the rotary potentiometer;

The algorithm adopts the improved PID algorithm, and the output pwm _(k) =kp(PT _(k) -PN)+ki(PT _(k) -PN)/n+kd(PT _(k-1) - PN). Use empirical method to adjust kp, ki, kd.

Generally speaking, the digital steering gear based on the hollow cup motor described in the present invention has better stability. Compared with the ordinary steering gear of the same level, it has faster speed, larger torque and smaller volume. This enables the present invention to be applied in more complicated and special occasions. The technologies and principles not described in detail in the present invention belong to the technologies known to those in the field of the present invention.

Claims (6)

1. A digital steering gear based on a hollow cup motor, including a control circuit board (6) and a servo control algorithm module thereof, characterized in that: the control circuit board (6) collects the current measured by the rotary potentiometer (7) The position of the rudder plate, after comparing with the input position and signal processing, outputs the driving signal of the hollow cup motor (8) through the drive circuit, and drives the output shaft (4) to rotate through the reducer (3) until the rudder surface reaches the input position, thus forming Closed-loop control, adjust the position of the steering wheel in real time according to the input signal. 2. A kind of digital steering gear based on hollow cup motor according to claim 1, characterized in that: output gear (11) and speed reducer (3) final stage gear and rotary potentiometer (7) pass through output shaft ( 4) Coaxial connection to ensure the real-time performance of position feedback, the casting body (13) on the second housing (5) cooperates with the metal rod (12) on the last stage gear of the reducer (3) to carry out the output shaft (4) 0-180 degree limit. 3. A digital steering gear based on a hollow cup motor according to claim 1, characterized in that: the overall size of the control circuit board (6) is controlled at 10mm*12mm*3mm, and the side is placed between the second housing (5) and The third housing (6) is close to the motor, and is insulated and fixed with insulating double-sided adhesive tape. The control circuit board (6) uses STC15W series single-chip microcomputer as the core, and comes with A/D conversion, clock circuit and PWM output module. , The control circuit also includes a voltage-stabilizing output circuit and a power drive circuit, thereby forming a complete signal processing and power drive, and realizing servo control of the motor position. 4. A digital steering gear based on a hollow cup motor according to claim 1, characterized in that: the speed reducer (3) includes five stages of reduction gears, and the reduction ratio is as high as 1:320. 5. A digital steering gear based on a coreless motor according to claim 1, characterized in that: the wire hole (9) is on the side of the third housing (10), and there are 4 wires connecting the internal circuit and the external drive circuit , including two power lines, one signal line, one feedback line, the power supply is 5V, and the feedback line outputs the current position signal. 6. A digital steering gear based on a coreless motor according to claim 1, characterized in that: the coreless motor (8) adopts a 716 ultra-high-speed coreless motor with a maximum speed of about 55000 RPM and a maximum stall current of 2A , the notable feature is super high speed, super power.