Motor braking method used when 270V all-electric aircraft landing gear is put down

Abstract

The invention provides a method for braking a motor when a 270V full-electric aircraft landing gear is put down, and relates to the technical field of motor control, and the method comprises the steps: calculating a difference value between a feedback speed and a target speed; judging whether the difference value is greater than a threshold value or not, if so, performing the next step, and if not, not performing motor braking; performing closed-loop control law calculation of 270V motor braking to obtain a control law calculation duty ratio; performing increment limitation on the control law calculation duty ratio to obtain an output duty ratio; and performing brake control on the motor according to the output duty ratio. According to the method, when the 270V full-electric aircraft landing gear is put down in a closed-loop mode, control over the putting-down speed of the landing gear is achieved through braking control over the motor, the problem that the speed is too high when the 270V full-electric aircraft landing gear is put down is solved, and the safety of the landing gear and the 270V motor is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of motor control, and in particular provides a motor braking method when a 270V all-electric aircraft landing gear is lowered. Background Art

[0002] In the landing gear retraction and extension control of the 270V all-electric aircraft, the landing gear is controlled by the 270V motor to complete the retraction and extension control. However, during the lowering process, due to the load of the landing gear, the landing gear lowering speed exceeds the target speed. At present, no braking control is performed in the middle section of the landing gear lowering process of the 270V all-electric aircraft, and the landing gear is allowed to move, and the speed closed-loop control is performed at the end. However, when controlling the final stage of the landing gear lowering of the all-electric aircraft, there are many uncontrollable factors. Due to the excessive speed during the lowering, the speed cannot be reduced to a safe speed range through the speed closed-loop of the final stage. The stop is completely guaranteed by the mechanism, which will cause damage to the mechanism, motor and motor controller, posing a great safety hazard. Summary of the invention

[0003] The purpose of this application is to prevent the damage of the landing gear mechanism, motor and motor controller due to excessive lowering speed due to load during the landing gear lowering process of an all-electric aircraft. A method of outputting a motor control PWM signal based on the speed difference between a target speed and a feedback speed is proposed to control the motor braking when the landing gear of a 270V all-electric aircraft is lowered.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: a motor braking method when the landing gear of a 270V all-electric aircraft is lowered, the method comprising:

[0005] Calculate the difference between the feedback speed and the target speed;

[0006] Determine whether the difference is greater than a threshold value. If so, proceed to the next step. If not, do not perform motor braking.

[0007] The closed-loop control law of 270V motor braking is calculated, and the duty cycle is calculated by the control law;

[0008] The duty cycle calculated by the control law is incrementally limited to obtain the output duty cycle;

[0009] The motor is braked according to the output duty cycle.

[0010] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical feature: the threshold value is determined according to the lowering time of the landing gear, the back electromotive force of the motor and the lowering speed of the landing gear.

[0011] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical features: the closed-loop control law calculation of the 270V motor braking obtains the duty cycle calculated by the control law, including:

[0012] Speed ​​percentage calculation, get speed percentage per_speed;

[0013] The control law is calculated based on the speed percentage, proportional coefficient and maximum output duty cycle.

[0014] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical feature: the speed percentage per_speed is: per_speed = (speed_feedback - speed_target) ÷ speed_target, wherein speed_target is the target speed; speed_feedback is the feedback speed.

[0015] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical features: the control law calculation based on the speed percentage, the proportional coefficient and the maximum output duty cycle includes: the control law calculates the duty cycle brake_out as

[0016] brake_out=kp×per_speed×max_l imit

[0017] Among them, per_speed is the speed percentage; kp is the proportional coefficient, which is set to 1; max_l imit is the maximum output duty cycle.

[0018] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical features: the incremental limitation of the duty cycle calculated by the control law to obtain the output duty cycle includes:

[0019] Duty cycle difference de l ta_pwm calculation;

[0020] Incremental limit processing.

[0021] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical features: the duty cycle difference de l ta_pwm is:

[0022] de l ta_pwm=brake_out–pwm_out

[0023] Among them, pwm_out is the output duty cycle; brake_out is the duty cycle calculated by the control law.

[0024] The motor braking method for lowering the landing gear of a 270V all-electric aircraft provided by the present invention also has the following technical features: the incremental limiting process includes:

[0025] When de l ta_pwm≥0:

[0026]

[0027] When de l ta_pwm<0:

[0028]

[0029] Among them, pwm_out is the output duty cycle.

[0030] Beneficial Effects

[0031] The motor braking method for lowering the landing gear of a 270V all-electric aircraft proposed in the present invention uses a closed-loop method to control the lowering speed of the landing gear by utilizing the motor's own braking control when the landing gear of the 270V all-electric aircraft is lowered, thereby solving the problem of the 270V all-electric aircraft lowering the landing gear at too high a speed and ensuring the safety of the landing gear and the 270V motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 This is a flow chart of the motor braking method provided by the present invention;

[0034] Figure 2 A flow chart of control law calculation provided by an embodiment of the present invention;

[0035] Figure 3 An incremental limit preprocessing flow chart provided by an embodiment of the present invention;

[0036] Figure 4 A diagram showing the relationship between the motor braking threshold and the motor back electromotive force provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present application is further described in detail below in conjunction with the accompanying drawings and examples, but it should be noted that these implementation methods are not limitations of the present application, and equivalent changes or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these implementation methods are all within the scope of protection of the present application.

[0038] In the description of the embodiments of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the creation of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the creation of the present application.

[0039] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0040] The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention of this application can be understood by specific circumstances.

[0041] like Figure 1-4 As shown, the embodiment of the present application provides a motor braking method when the landing gear of a 270V all-electric aircraft is lowered, and the method includes:

[0042] Calculate the difference between the feedback speed and the target speed;

[0043] Determine whether the difference is greater than a threshold value. If so, proceed to the next step. If not, do not perform motor braking.

[0044] The closed-loop control law of 270V motor braking is calculated, and the duty cycle is calculated by the control law;

[0045] The duty cycle calculated by the control law is incrementally limited to obtain the output duty cycle;

[0046] The motor is braked according to the output duty cycle.

[0047] In some embodiments, the threshold is determined based on the landing gear lowering time, the back electromotive force of the motor, and the landing gear lowering speed. If the back electromotive force generated by the motor is larger, the threshold is set larger; if the back electromotive force generated by the motor is smaller, the threshold is set smaller. If the landing gear lowering time is smaller than the landing gear retraction time, the threshold is set larger; if the landing gear lowering time is larger than the landing gear retraction time, the threshold is set smaller. If the ratio of the landing gear lowering speed to the motor rated speed is smaller, the threshold is set smaller; if the ratio of the landing gear lowering speed to the motor rated speed is larger, the threshold is set larger.

[0048] In some embodiments, the closed-loop control law calculation of the 270V motor braking to obtain the control law calculation duty cycle includes:

[0049] Speed ​​percentage calculation, get speed percentage per_speed;

[0050] The control law is calculated based on the speed percentage, proportional coefficient and maximum output duty cycle.

[0051] In some embodiments, the speed percentage per_speed is: per_speed = (speed_feedback - speed_target) ÷ speed_target

[0052] Among them, speed_target is the target speed; speed_feedback is the feedback speed.

[0053] In some embodiments, the control law calculation according to the speed percentage, the proportional coefficient and the maximum output duty cycle includes: the control law calculates the duty cycle brake_out as

[0054] brake_out=kp×per_speed×max_l imit

[0055] Among them, per_speed is the speed percentage; kp is the proportional coefficient, which is set to 1; max_l imit is the maximum output duty cycle.

[0056] In some embodiments, the step of performing incremental limitation on the duty cycle calculated by the control law to obtain the output duty cycle includes:

[0057] Duty cycle difference de l ta_pwm calculation;

[0058] Incremental limit processing.

[0059] In some embodiments, the duty cycle difference de l ta_pwm is:

[0060] de l ta_pwm=brake_out–pwm_out

[0061] Among them, pwm_out is the output duty cycle; brake_out is the duty cycle calculated by the control law.

[0062] In some embodiments, the incremental limit processing includes:

[0063] When de l ta_pwm≥0:

[0064]

[0065] When de l ta_pwm<0:

[0066]

[0067] Among them, pwm_out is the output duty cycle.

[0068] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A motor braking method for lowering the landing gear of a 270V all-electric aircraft, characterized in that: The method comprises: Calculate the difference between the feedback speed and the target speed; Determine whether the difference is greater than a threshold value. If so, proceed to the next step. If not, do not perform motor braking. The closed-loop control law of 270V motor braking is calculated, and the duty cycle is calculated by the control law; The duty cycle calculated by the control law is incrementally limited to obtain the output duty cycle; The motor is braked according to the output duty cycle.

2. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 1 is characterized in that: The threshold is determined according to the landing gear lowering time, the back electromotive force of the motor and the landing gear lowering speed.

3. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 1 is characterized in that: The closed-loop control law calculation of the 270V motor braking obtains the control law calculation duty cycle including: Speed ​​percentage calculation, get speed percentage per_speed; The control law is calculated based on the speed percentage, proportional coefficient and maximum output duty cycle.

4. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 3 is characterized in that: The speed percentage per_speed is: per_speed=(speed_feedback–speed_target)÷speed_target where, speed_target is the target speed; speed_feedback is the feedback speed.

5. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 3 is characterized in that: The control law calculation according to the speed percentage, the proportional coefficient and the maximum output duty cycle includes: the control law calculates the duty cycle brake_out as follows: brake_out=kp×per_speed×max_limit Among them, per_speed is the speed percentage; kp is the proportional coefficient, which is set to 1; max_limit is the maximum output duty cycle.

6. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 1 is characterized in that: The step of performing incremental limitation on the duty cycle calculated by the control law to obtain the output duty cycle includes: Duty cycle difference delta_pwm calculation; Incremental limit processing.

7. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 6 is characterized in that: The duty cycle difference delta_pwm is: delta_pwm=brake_out–pwm_out Among them, pwm_out is the output duty cycle; brake_out is the duty cycle calculated by the control law.

8. The motor braking method for lowering the landing gear of a 270V all-electric aircraft according to claim 6 is characterized in that: The incremental limit processing includes: When delta_pwm ≥ 0: 0≤delta_pwm<125pwm_out=brake_out 125≤delta_pwm<250pwm_out=pwm_out+12 250≤delta_pwm<1062pwm_out=pwm_out+25 1062≤delta_pwm pwm_out=1062 When delta_pwm<0: 0≤delta_pwm<125pwm_out=brake_out 125≤delta_pwm<250pwm_out=pwm_out-12 250≤delta_pwm<1062pwm_out=pwm_out–251062≤delta_pwm pwm_out=pwm_out–25wherein, pwm_out is the output duty cycle.

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