CN114325383B - Brushless motor winding fault detection system and method for unmanned helicopter - Google Patents

Abstract

The invention discloses a brushless motor winding fault detection system and method for an unmanned helicopter, wherein the system comprises a power module, a main control unit, a driving unit, an acquisition and processing unit and a display unit; the power supply module is used for providing power supply for the system; the input end of the acquisition and processing unit is connected with a motor tap cable of the brushless motor winding, and a motor tap voltage value is output; the main control unit is used for judging whether the voltage value of the motor tap is in a set threshold range or in a fault state, and outputting PWM waves to the driving unit; the driving unit is used for driving the brushless motor to transport; the display unit is connected with the main control unit and is used for displaying the state of the brushless motor winding. The invention mixes the detection circuit of the DC brushless motor into the detection circuit of the DC brushless motor, thereby not affecting the function of controlling the normal operation of the motor, but also realizing the requirement of detecting the state of the motor in real time in the operation process of the brushless motor.

Description

A brushless motor winding fault detection system and method for unmanned helicopter

Technical Field

The invention relates to a motor winding fault detection method, and in particular to a brushless motor winding fault detection system and method for an unmanned helicopter.

Background technique

DC motors are widely used in all walks of life. With the increasing requirements for service life, speed, high power and other indicators, the market share of brushless DC motors has increased year by year. The simplest detection method for brushless DC motors is to use the "buzzer" gear of a multimeter to test the continuity of the motor windings; use the "ohm" gear of a multimeter to test the resistance of the three-phase windings; use a high-voltage meter to inject and test the resistance between the motor windings and the housing. However, these methods can only test the brushless motor windings in a simple and static manner, and cannot be used as an effective method for dynamic and real-time detection of the reliable operation of brushless motors.

Summary of the invention

The purpose of the present invention is to provide a brushless motor winding fault detection system and method for an unmanned helicopter, which can detect winding faults in real time during the operation of the brushless motor on the unmanned helicopter, and stop the operation of the brushless motor in time when a fault occurs, thereby improving the safety of the motor during operation.

The technical solution for achieving the purpose of the present invention is:

A brushless motor winding fault detection system for an unmanned helicopter includes a power module, a main control unit, a drive unit, a collection and processing unit, and a display unit; wherein:

The power module is used to provide power to the system;

The input end of the acquisition and processing unit is connected to the motor tap cable of the brushless motor winding, and outputs the motor tap voltage value;

The main control unit is used to determine whether the motor tap voltage value is within a set threshold range or in a fault state, and output a PWM wave to the drive unit;

The driving unit is used to drive the transportation of the brushless motor;

The display unit is connected to the main control unit and is used to display the state of the brushless motor winding.

A method based on the brushless motor winding fault detection system for an unmanned helicopter comprises the following steps:

The motor tap cable of the brushless motor winding is connected to the acquisition and processing unit;

The drive unit drives the brushless motor to operate;

The acquisition and processing unit acquires the motor tap voltage value and outputs it to the main control unit;

The main control unit determines whether the motor tap voltage value is within the set threshold range. If not, the main control unit determines that the brushless motor is in a fault state, and sends the determination result to the drive unit, while displaying the brushless motor state on the display unit;

The driving unit controls the brushless motor to move or stop according to the judgment result of the main control unit.

Compared with the prior art, the present invention has the following significant effects: the acquisition and processing unit circuit designed by the present invention does not require the aid of additional instruments and equipment, and only needs to lead out the middle tap of the three-phase winding of the brushless motor and connect the motor tap cable to accurately acquire the motor tap voltage value; the present invention can detect the fault of the brushless motor winding for an unmanned helicopter in real time, and at the same time, the detection circuit can be integrated into the detection loop of the entire system without consuming the resources of the main control unit, and can also be independently formed into a health diagnosis detection system. The circuit and principle of the present invention are simple and the detection efficiency is high; the present invention improves the test performance of the unmanned helicopter system and provides effective information input for the fault switching instruction of the redundancy system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a block diagram of a brushless motor winding fault detection system for an unmanned helicopter according to the present invention.

FIG. 2 is a schematic diagram of the main control unit determining the winding state of the brushless motor in the present invention.

FIG3 is a circuit diagram of the acquisition and processing unit in the present invention.

FIG. 4 is a schematic diagram of a brushless motor winding tap.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

In conjunction with Figures 1 and 4, the brushless motor winding fault detection system for an unmanned helicopter proposed in this embodiment is mainly composed of a power module, a main control unit, a drive unit, an acquisition and processing unit, a host computer interface, and a motor tap cable. The middle tap cable of the brushless motor winding to be tested is connected to the acquisition and processing unit. When the main control unit inputs the output PWM wave into the drive unit and completes the power amplification, the brushless motor starts to rotate. The main control unit can start to judge the state of the brushless motor through comparison with a comparator: no fault, short circuit fault, and open circuit fault. In conjunction with Figure 2, the specific judgment method is as follows:

(1) If the brushless motor can work normally, its tap voltage value should be within the normal threshold range. At this time, the main control unit matches the truth table in the main control unit program according to the output I/O quantity of the acquisition and processing unit, and outputs no fault information on the upper computer interface. The actual transmission value is 1;

(2) If a short circuit occurs in the brushless motor, the tap voltage value exceeds the normal threshold range. At this time, the main control unit matches the truth table in the main control unit program according to the output I/O quantity of the acquisition and processing unit, and outputs the short circuit information on the upper computer interface. The actual transmission value is 3;

(3) If a short circuit occurs in the brushless motor at this time, its tap voltage value is lower than the normal threshold range. At this time, the main control unit matches the truth table in the main control unit program according to the output I/O quantity of the acquisition and processing unit, and outputs the short circuit information on the upper computer interface. The actual transmission value is 0.

At this point, the real-time detection function of any phase winding coil of the brushless motor in three modes, namely, normal mode, short circuit fault mode and open circuit fault mode, can be realized.

Combined with Figure 3, the circuit topology of the acquisition and processing unit is designed as follows: the motor winding tap signal is connected to one end of the first resistor R183, the other end of the first resistor R183 is connected to one end of the first capacitor C206, and is connected to the in-phase input ends of the two operational amplifiers at the same time, and the other end of the first capacitor C206 is grounded. The inverting input end of the first operational amplifier N1A is connected to the voltage-divided signal through the second resistor R59 and the third resistor R78, the other end of the second resistor R59 is connected to the 28V voltage, and the other end of the third resistor R78 is grounded; similarly, the inverting input end of the second operational amplifier N1B is connected to the voltage-divided signal through the fourth resistor R189 and the fifth resistor R60, the other end of the fourth resistor R189 is connected to the 28V voltage, and the other end of the fifth resistor R60 is grounded. The two outputs of the operational amplifier are connected to the two cathodes of the high-speed photoelectric coupler, wherein the output of the operational amplifier of the first group is connected to the cathode (pin 2) of the first group of light-emitting diodes of the high-speed photoelectric coupler D18; the output of the operational amplifier of the second group is connected to the cathode (pin 3) of the second group of light-emitting diodes of the high-speed photoelectric coupler D18. The two positive pins (pin 1 and pin 4) of the high-speed photoelectric coupler D18 are respectively connected to the 28V voltage signal flowing through the sixth current-limiting resistor R35 and the seventh resistor R36. The two output pins (pin 7 and pin 6) of the photoelectric coupler are respectively pulled up by the 5V of the eighth resistor R47 and the ninth resistor R48, and then enter the main control unit through the tenth current-limiting resistor R195 and the eleventh resistor R196. In addition, the second capacitor C220 is the decoupling capacitor of the operational amplifier, and the third capacitor C221 is the decoupling capacitor of the high-speed photoelectric coupler.

The power supply module in the brushless motor winding fault detection method for the unmanned helicopter can be selected as AC/DC or DC/DC according to the actual application requirements.

The main control unit in the brushless motor winding fault detection method for the unmanned helicopter can be selected from a common single-chip microcomputer, ARM, DSP, FPGA, etc. according to the developer's ability.

In the brushless motor winding fault detection method for unmanned helicopters, the drive unit may use a general MOS tube lap circuit or a ready-made brushless motor drive module according to the requirements of the environment.

The setting of the voltage comparison threshold in the acquisition and processing unit in the brushless motor winding fault detection method for the unmanned helicopter is carried out by matching the resistance value according to the actual operating conditions.

In the brushless motor winding fault detection method for unmanned helicopter, the fault status information of the brushless motor winding can be displayed in the upper computer interface, can be displayed by a digital tube, and can be displayed by an LED indicator light according to the actual experience of the developer.

The brushless motor winding fault detection system proposed by the present invention integrates the detection circuit of the DC brushless motor into the detection loop of the DC brushless motor, which does not affect the function of controlling the normal operation of the motor, and can meet the demand for real-time detection of the motor status during the operation of the brushless motor. By uploading the motor status to the monitoring interface in real time, it not only reduces the detection time and frequency of professionals, but also improves the safety of the motor during operation.

Claims (9)

1. A brushless motor winding fault detection system for an unmanned helicopter, characterized in that it includes a power module, a main control unit, a drive unit, a collection and processing unit and a display unit; wherein: The power module is used to provide power to the system; The input end of the acquisition and processing unit is connected to the motor tap cable of the brushless motor winding, and outputs the motor tap voltage value; The main control unit is used to determine whether the motor tap voltage value is within a set threshold range or in a fault state, and output a PWM wave to the drive unit; the method for the main control unit to determine the fault state is: the main control unit compares through a comparator, if the motor tap voltage value is lower than the minimum value of the set threshold range, the brushless motor has a short circuit fault; if the motor tap voltage value is higher than the maximum value of the set threshold range, the brushless motor has an open circuit fault, otherwise the brushless motor is in a normal operating state; The driving unit is used to drive the transportation of the brushless motor; The display unit is connected to the main control unit and is used to display the state of the brushless motor winding. 2. The brushless motor winding fault detection system for an unmanned helicopter according to claim 1, characterized in that the acquisition and processing unit comprises a first operational amplifier (N1A), a second operational amplifier (N1B) and a photoelectric coupler (D18), the in-phase input terminal of the first operational amplifier (N1A) is connected to one end of a first resistor (R183), one end of a first capacitor (C206) and the in-phase input terminal of the second operational amplifier (N1B), the other end of the first resistor (R183) is connected to a motor tap cable, the first capacitor (C206) and an output terminal of the first operational amplifier (N1A) are grounded, the inverting input terminal of the second operational amplifier (N1B) is connected to one end of a fourth resistor (R189) and a fifth resistor (R60), the other end of the fourth resistor (R189) is connected to a 28V voltage, the other end of the fifth resistor (R60) is grounded, the inverting input terminal of the first operational amplifier (N1A) is connected to one end of the second resistor (R59) and a third resistor (R78), the second resistor (R5 9) is connected to a 28V voltage, the other end of the third resistor (R78) is grounded, the first operational amplifier (N1A) is connected to one end of the second capacitor (C220) for decoupling, and the second capacitor (C220) is connected to a 28V voltage, and the other end of the second capacitor (C220) is grounded, the output ends of the first operational amplifier (N1A) and the second operational amplifier (N1B) are respectively connected to the two cathode pins of the photoelectric coupler (D18), and the two anode pins of the photoelectric coupler (D18) are respectively connected to the two cathode pins of the photoelectric coupler (D18). The pins are respectively connected to one end of a sixth resistor (R35) and a seventh resistor (R36) for current limiting, the other ends of the sixth resistor (R35) and the seventh resistor (R36) are connected to a 28V voltage, and the two output pins of the photoelectric coupler (D18) are respectively pulled up by 5V of an eighth resistor (R47) and a ninth resistor (R48) and then limited to enter the main control unit through a tenth resistor (R195) and an eleventh resistor (R196), and at the same time, the output end of the photoelectric coupler (D18) is connected to a third capacitor (C221) for decoupling. 3. The brushless motor winding fault detection system for an unmanned helicopter according to claim 2, characterized in that the photoelectric coupler (D18) adopts a HCPL0631 photoelectric coupler, the first pin (A1) of the photoelectric coupler (D18) is connected to one end of the sixth resistor (R35), the fourth pin (A2) of the photoelectric coupler (D18) is connected to one end of the seventh resistor (R36), the second pin (K1) of the photoelectric coupler (D18) is connected to the output end of the first operational amplifier (N1A), the third pin (K2) of the photoelectric coupler (D18) is connected to the output end of the second operational amplifier (N1B), and the photoelectric coupler ( The eighth pin (VCC) of the photoelectric coupler (D18) is connected to one end of the third capacitor (C221) and a 5V voltage, and the other end of the third capacitor (C221) is grounded, the seventh pin (V1) of the photoelectric coupler (D18) is connected to one end of the eighth resistor (R47) and the tenth resistor (R195), and the other end of the eighth resistor (R47) is connected to the 5V voltage, the sixth pin (V2) of the photoelectric coupler (D18) is connected to one end of the ninth resistor (R48) and the eleventh resistor (R196), and the other end of the ninth resistor (R48) is connected to the 5V voltage, and the other ends of the tenth resistor (R195) and the eleventh resistor (R196) are both connected to the main control unit. 4. The brushless motor winding fault detection system for an unmanned helicopter according to claim 2, characterized in that both the first operational amplifier (N1A) and the second operational amplifier (N1B) are LM158 amplifiers. 5. The brushless motor winding fault detection system for an unmanned helicopter according to claim 1, characterized in that the power supply module adopts an AC/DC or DC/DC converter. 6. The brushless motor winding fault detection system for an unmanned helicopter according to claim 1, characterized in that the main control unit adopts a single-chip microcomputer, ARM, DSP or FPGA. 7. The brushless motor winding fault detection system for an unmanned helicopter according to claim 1, characterized in that the drive unit adopts a MOS tube lap circuit. 8. The brushless motor winding fault detection system for an unmanned helicopter according to claim 1, characterized in that the display unit adopts a digital tube or an LED display screen. 9. A method for detecting a brushless motor winding fault for an unmanned helicopter according to any one of claims 1 to 8, characterized in that it comprises the following steps: The motor tap cable of the brushless motor winding is connected to the acquisition and processing unit; The drive unit drives the brushless motor to operate; The acquisition and processing unit acquires the motor tap voltage value and outputs it to the main control unit; The main control unit determines whether the motor tap voltage value is within the set threshold range. If not, the main control unit determines that the brushless motor is in a fault state, and sends the determination result to the drive unit, while displaying the brushless motor state on the display unit; The driving unit controls the brushless motor to move or stop according to the judgment result of the main control unit.