CN119093780A

CN119093780A - A safety control method based on motor ramp shutdown

Info

Publication number: CN119093780A
Application number: CN202411588481.2A
Authority: CN
Inventors: 付新; 孙祝兵; 胡亮; 苏芮
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2024-11-08
Filing date: 2024-11-08
Publication date: 2024-12-06
Anticipated expiration: 2044-11-08

Abstract

The invention relates to a motor ramp shutdown-based safe control method. The invention discloses a motor ramp shutdown-based safe control method, which comprises the following steps that S1, a motor receives a shutdown instruction, S2, a driving control module detects whether the motor is on a ramp or not after receiving the shutdown instruction, S3, when the motor is judged not to be on the ramp, the remote control module and the driving control module are directly powered off, when the motor is judged to be on the ramp, a ramp shutdown flow is executed, in the ramp shutdown flow of the step S3, after the driving control module receives the shutdown instruction, the remote control module is powered off so that the motor generates a reverse torque with a required value, and when the remote control module is powered off for a first set period, the driving control module controls the motor to stop generating the reverse torque, and the motor is actively shorted. According to the invention, the driving control module controls the motor to output reverse torque, so that a scooter or wheelchair with the motor is prevented from walking on a slope, and an electromagnetic brake is not required to be arranged on the motor.

Description

Safety control method for shutdown based on motor ramp

Technical Field

The invention relates to a motor ramp shutdown-based safe control method.

Background

The motor of a slow-speed scooter such as a scooter and a wheelchair is usually provided with a brake, if the mechanical brake is adopted, the scooter/wheelchair needs to be manually braked after being powered off on a slope, and the applicable crowd of the scooter/wheelchair is usually old people with limited behavior ability, some users can need a long time to complete the braking action, and the risk of shutdown on the slope is high, so that the scooter/wheelchair can often adopt electromagnetic brake.

However, when the scooter/wheelchair using the electromagnetic brake is in normal running, the electromagnetic brake is always powered on, so that the energy consumption is high when the scooter/wheelchair is in running, a battery with larger size is needed, or the running distance is limited. Meanwhile, the weight of the whole scooter/wheelchair is increased due to the electromagnetic brake, so that the light weight of the scooter/wheelchair is affected, and the assembly flow is increased.

Disclosure of Invention

The invention aims to provide a motor-based ramp shutdown safe control method which can enable a scooter/wheelchair to be lighter, is more convenient to produce and assemble and can prolong the travel.

In order to achieve the above purpose, the invention adopts a motor ramp shutdown based safe control method, which comprises the following steps:

s1, a motor receives a shutdown instruction;

S2, after receiving a shutdown instruction, the drive control module detects whether the motor is positioned on the ramp;

S3, when the motor is judged not to be on the slope, the remote control module and the drive control module are directly powered off;

executing a ramp shutdown flow when the motor is judged to be on the ramp;

In the ramp shutdown process of step S3, after the driving control module receives a shutdown instruction, the remote control module shuts down, the driving control module calculates a first braking torque output value PWM1 required by the motor to generate a reverse torque according to the angular speed and the moving distance when the wheels rotate, and outputs the PWM1 to the motor to drive, so that the motor generates the reverse torque with a required value;

When the remote control module is powered off for a first set period of time, the drive control module controls the motor to stop generating reverse torque, and the motor is actively short-circuited.

According to the scheme of the invention, the drive control module is used for controlling the motor to output the reverse moment, so that the scooter/wheelchair is prevented from walking on a slope, the braking function is realized, an electromagnetic brake is not required to be arranged on the scooter/wheelchair, the production assembly procedure can be reduced, the weight of the scooter/wheelchair is reduced, the light weight is realized, the electromagnetic brake is not required to work all the time when the scooter/wheelchair is used, and the energy consumption can be reduced to prolong the travel of the scooter/wheelchair.

The motor is actively short-circuited, so that the scooter/wheelchair with the motor can slowly walk a slope, the scooter/wheelchair with the motor is prevented from rapidly walking the slope under the action of dead weight after electricity is used up, the use safety is improved, and the scooter/wheelchair is enabled to still have electric quantity after being moved to the flat ground.

Preferably, in step S2, the magnitude relation between the current I of the motor and the minimum current i_limit when the motor is operating is compared, and if I > i_limit, it is indicated that the motor is located on the ramp.

Preferably, in step S2, the magnitude relation between the second braking torque output value PWM2 of the motor on the slope and pwm_limit is compared, wherein pwm_limit is the minimum braking torque output value of the motor when judging whether the motor is on the slope, when PWM2< -pwm_limit, the motor is judged to be on the downhill slope, and when PWM2> pwm_limit, the motor is judged to be on the uphill slope. After mutual calibration, the detection accuracy is higher.

Preferably, in step S2, when the motors are hub motors, PWM2 of all motors are detected, the magnitude relation between PWM2 and pwm_limit of all motors is compared, when PWM2 of all motors is smaller than-pwm_limit, the motor is determined to be on a downhill slope, and when PWM2 of all motors is larger than pwm_limit, the motor is determined to be on an uphill slope.

Preferably, in step S3, if it is determined that the scooter/wheelchair is on the ramp, the drive control module generates a command to the remote control module, the remote control module sends an alarm signal, and after the shutdown key is pressed again, the remote control module shuts down.

Preferably, in step S3, the motor is actively shorted by switching to short-circuit the lower three tubes of the MOS of the drive control module. After the lower three pipes of the MOS are short-circuited, the three phases are short-circuited, the motor is turned into a power generation mode, and the movement direction of the motor rotor is opposite to the direction of the rotor rotating cutting magnetic field during normal slope walking, so that the motor rotor rotates with resistance, and slow down walking is realized.

Preferably, in step S3, after the motor is actively shorted for a second set period of time, or after the motor is detected to be in the flat ground for a third set period of time, and after the motor is actively shorted for a fourth set period of time, the drive control module is turned off.

Preferably, the calculation formula of PWM1 is as follows:

PWM1=-Kp*Pos+SumI;

SumI_{Rear part (S)}=SumI_{Front part}+(-Spd*ki);

Wherein Kp is a movement distance adjustment parameter, pos is a movement distance, positive and negative in forward direction, sumI is a speed adjustment integral value, spd is a rotation speed, positive in forward direction, negative in backward direction, ki is an adjustment ratio, and sumi=0 if spd× SumI >0 is used for preventing the integral of speed from generating moment same as the movement direction.

The invention can avoid walking the slope on the slope to realize the braking function by controlling the motor to output the reverse moment by the driving control module, thereby avoiding the electromagnetic brake on the motor, reducing the production and assembly procedures, reducing the weight of the scooter/wheelchair to realize the light weight, and simultaneously avoiding the electromagnetic brake to work all the time when the scooter/wheelchair is used, and reducing the energy consumption to prolong the travel of the scooter/wheelchair.

Drawings

Fig. 1 is a flow chart of a control principle of the present invention.

Fig. 2 is a schematic diagram of control of a three-way short circuit under a motor.

Detailed Description

The invention is further described below with reference to the drawings and specific embodiments.

As shown in fig. 1, the embodiment discloses a motor ramp shutdown-based safe control method, which includes the following steps:

S1, pressing a shutdown key, and sending the shutdown instruction to a drive control module through a serial communication protocol after the remote control module obtains the shutdown instruction. The motor is controlled by the drive control module to output a moment opposite to the moving direction (landslide) of the wheelchair, and the wheel at the motor rotates, so that the electronic brake is realized.

S2, after receiving a shutdown instruction, the drive control module detects whether the scooter/wheelchair is on the ramp. Comparing the magnitude relation between the current I of the two hub motors of the scooter/wheelchair and the minimum current I_limit of the motor during operation, and if I > I_limit, indicating that the scooter/wheelchair is positioned on the ramp. The larger the current is, the larger the stress received by the illustrated scooter/wheelchair in a parking state is, and the larger the ramp is further deduced.

And comparing the magnitude relation between a second braking torque output value PWM2 of the scooter/wheelchair on the ramp and Pwm_limit, wherein Pwm_limit is the minimum braking torque output value of the motor when judging whether the scooter/wheelchair is on the ramp, judging that the scooter/wheelchair is on a downhill slope when PWM2< -Pwm_limit, and judging that the scooter/wheelchair is on an uphill slope when PWM2> Pwm_limit. Wherein, a negative PWM2 value indicates that the motor provides a negative force, and further indicates that the motor is in a downhill state at this time, and in an uphill state otherwise.

S3, if the scooter/wheelchair is judged not to be on the ramp, the remote control module and the drive control module are directly powered off, and if the scooter/wheelchair is judged to be on the ramp, a ramp shutdown process is executed.

In the ramp shutdown process, if the scooter/wheelchair is judged to be on the ramp, the driving control module generates an instruction to the remote control module, the remote control module sends an alarm signal, the alarm signal comprises voice of 'long-time pressing shutdown' again, after a shutdown key is pressed down again by a user, the remote control module is shut down, meanwhile, the driving control module calculates a first braking moment output value PWM1 required by the motor for generating reverse moment according to the angular speed and the moving distance of the wheels, and the PWM1 is output to the motor to drive so as to enable the motor to generate the reverse moment with a required value, thereby preventing the scooter/wheelchair from walking the ramp.

Wherein PWM1 = -Kp pos+ SumI; sumI _{Rear part (S)}=SumI_{Front part} + (-Spd × ki), kp is a movement distance adjustment parameter, pos is a movement distance, forward is positive, backward is negative, sumI is a speed adjustment integral value, spd is a rotation speed, forward is positive, backward is negative, ki is an adjustment ratio, and if Spd × SumI >0, sumi=0, the purpose is to prevent the integral of speed from being the same as the speed direction, and to generate a moment same as the movement direction.

After a first set time period after the remote control module is shut down, the driving control module controls the motor to stop generating the directional moment, the motor is switched to short-circuit a lower three-tube of the MOS of the driving control module (the schematic diagram is shown in fig. 2), and after the motor is actively short-circuited for a second set time period, or the motor is actively short-circuited for a fourth set time period, and after the fact that the scooter/wheelchair is in a flat ground for a third set time period is detected, the driving control module is shut down. The first set duration and the fourth set duration in this embodiment are both 60S, the second set duration is 40S, and the third set duration is 80S.

According to the embodiment, the drive control module is used for controlling the motor to output reverse torque, so that the scooter/wheelchair is prevented from walking on a slope, a braking function is realized, an electromagnetic brake is not required to be arranged on the scooter/wheelchair, the production assembly process can be reduced, the weight of the scooter/wheelchair is reduced to realize light weight, the electromagnetic brake is not required to work all the time when the scooter/wheelchair is used, and the energy consumption can be reduced to prolong the travel of the scooter/wheelchair.

Claims

1. A safety control method based on motor ramp shutdown, characterized by comprising the following steps:

S1. The motor receives a shutdown command;

S2. After receiving the shutdown command, the drive control module detects whether the motor is on the slope;

S3. When it is determined that the motor is not on the ramp, the remote control module and the drive control module are directly shut down;

When it is determined that the motor is on a slope, the slope shutdown process is executed;

In the ramp shutdown process of step S3, after the drive control module receives the shutdown command, the remote control module shuts down, and the drive control module calculates the first brake torque output value PWM1 required for the motor to generate a reverse torque according to the angular velocity and moving distance of the wheel during rotation, and outputs PWM1 to the motor drive to enable the motor to generate the required reverse torque;

When the remote control module is turned off for a first set time, the drive control module controls the motor to stop generating reverse torque, and the motor actively short-circuits.

2. A safety control method based on motor ramp shutdown according to claim 1, characterized in that: in step S2, the magnitude relationship between the motor current I and the minimum current I_limit when the motor is working is compared. If I＞I_limit, it means that the motor is on a ramp.

3. A safety control method based on motor ramp shutdown according to claim 1 or 2, characterized in that: in step S2, the second braking torque output value PWM2 of the motor on the ramp is compared with Pwm_limit, Pwm_limit is the minimum braking torque output value of the motor when judging whether the motor is on a ramp; when PWM2＜-Pwm_limit, it is judged that the motor is on a downhill ramp, and when PWM2>Pwm_limit, it is judged that the motor is on an uphill ramp.

4. A safety control method based on motor ramp shutdown according to claim 3, characterized in that: in step S2, when the motor is a hub motor, the PWM2 of all motors is detected, and the size relationship between the PWM2 of all motors and the Pwm_limit is compared. When the PWM2 of all motors is less than -Pwm_limit, it is judged that the motor is on a downhill slope; when the PWM2 of all motors is greater than Pwm_limit, it is judged that the motor is on an uphill slope.

5. A safety control method based on motor ramp shutdown according to claim 1, characterized in that: in step S3, if it is determined that the motor is on a ramp, the drive control module sends an instruction to the remote control module, and the remote control module sends an alarm signal. After the shutdown button is pressed again, the remote control module shuts down.

6. A motor ramp shutdown safety control method according to claim 1, characterized in that: in step S3, the motor is actively short-circuited by switching to short-circuit the lower three tubes of the MOS of the drive control module.

7. A safety control method based on motor ramp shutdown according to claim 1, characterized in that: in step S3, the drive control module shuts down after the motor actively short-circuits for a second set time, or after it is detected that the motor is on flat ground for a third set time, and after the motor actively short-circuits for a fourth set time.

8. According to the safety control method for motor ramp shutdown according to claim 1, the calculation formula of PWM1 is as follows:

PWM1=-Kp*Pos+SumI;

SumI _after = SumI _before + (-Spd*ki);

Among them, Kp is the moving distance adjustment parameter, Pos is the moving distance, which is positive when moving forward and negative when moving backward; SumI is the speed adjustment integral value, Spd is the rotation speed, which is positive when moving forward and negative when moving backward, and ki is the adjustment ratio; if Spd*SumI>0, SumI=0, it means that the moving direction and the braking direction are the same, then SumI is cleared and SumI is _recalculated .