CN110455522B

CN110455522B - Random test method for vehicle door endurance test bed based on servo electric cylinder

Info

Publication number: CN110455522B
Application number: CN201910884133.2A
Authority: CN
Inventors: 张德俊; 周贤文; 顾伟
Original assignee: Shanghai Maritime University
Current assignee: Shanghai Maritime University
Priority date: 2019-09-19
Filing date: 2019-09-19
Publication date: 2021-03-26
Anticipated expiration: 2039-09-19
Also published as: CN110455522A

Abstract

The invention discloses a random test method for a vehicle door endurance test bed based on a servo electric cylinder. Comprises 3 steps: and generating and outputting a speed given signal x, outputting a displacement given signal y, and switching speed control and position control. Aiming at the fatigue test of the car door, in order to enable the test process to simulate the actual situation of opening and closing the car door by a person to the maximum extent, a speed given signal x adopts the random speed, a displacement given signal y is obtained by integrating the speed given signal x, a servo electric cylinder is used as an actuator to drive the car door to carry out opening and closing movement, the target opening position is manually set, the random given speed is adopted to complete each time of the endurance test of the car door, and the test result is more convincing.

Description

Random test method for vehicle door endurance test bed based on servo electric cylinder

The technical field is as follows:

the invention relates to a vehicle door fatigue test, in particular to a random test method of a vehicle door endurance test bed based on a servo electric cylinder.

Background art:

the vehicle door durability test bed is a test device for detecting the performances of the vehicle door, such as safety, reliability, durability, reasonable mechanical structure and the like, and guarantees the safety of passengers and drivers in the vehicle. At present, an air cylinder is mostly adopted as an actuator in a vehicle door endurance test bed, a vehicle door is driven to complete opening and closing work for a certain number of times at the same speed, and test conditions are recorded to obtain results. However, in practical situations, because the speeds of opening the doors of different people are different, especially when the opening speed of the doors is high, the service life of the doors is greatly influenced, the test result obtained by performing the door endurance test for a certain number of times at the same speed is lack of persuasion, and investigation and statistics show that the opening and closing frequency of the doors of small cars providing passenger transport services such as taxis is the highest, and because the habits of guests are different, the opening and closing speeds of the doors are greatly different, at this time, the conventional test method is difficult to meet the requirements of the door endurance test, and potential hazards are left for the safety of the passengers and drivers on the cars.

The invention content is as follows:

in order to overcome the problems, the invention provides a random test method of a vehicle door endurance test bed based on a servo electric cylinder. The technical scheme of the invention is as follows:

a random test method for a vehicle door durability test bed based on a servo electric cylinder is realized by depending on the servo electric cylinder, and the servo electric cylinder is used as an actuator to drive a vehicle door to complete opening and closing work.

A random test method of a vehicle door endurance test bed based on a servo electric cylinder is mainly used for completing a vehicle door fatigue test by adopting a random speed. The method comprises the steps that 1m/s-4m/s of random signals which are normally distributed in a standard mode are used as speed signals, the sampling period of the speed signals is 12s, square wave signals with the amplitude of 1, the period of 12s and the duty ratio of 50% are used as speed direction signals, the speed signals and the speed direction signals are used as input of a multiplier, and the output is speed given signals x; the displacement given signal y is obtained by adopting a speed given signal x integral mode, so that the error in the position tracking process is ensured to be small, and the problem of considering the displacement direction is avoided; adding a target position r, namely a set value of a car door opening position in a test, when switching between speed control and position control is designed, processing a displacement given signal by using a saturator, comparing the displacement given signal y with the output of the saturator by using a comparator, judging whether the displacement given signal y meets the target position r, if so, outputting 0 by using the comparator, multiplying the speed given signal x by a multiplier, setting the speed given to be 0, and performing position control to play a main role; if not, the comparator outputs 1, the speed given signal x is multiplied by the multiplier, the speed given signal x is kept unchanged, and the speed control plays a main role.

According to the invention, a speed range of 1m/s-4m/s in standard normal distribution is adopted as a given speed according to actual survey data, the displacement of the car door is 1m, the opening and closing speed is high, the running time is short, in order to ensure that the speed can reach the given value, a servo electric cylinder is adopted as an actuator, and the servo electric cylinder has high response speed and high precision and can meet the test requirement; the random speed setting can simulate the condition of opening and closing the car door by a person under the actual condition to the maximum extent, so that the test result is more convincing; the displacement given signal is obtained by adopting a speed signal integration mode, so that the influence of large error on speed control in the position tracking process is prevented, and the problem of considering the displacement direction is avoided; the switching of speed control and position control is completed by adopting a saturator, a comparator and a multiplier, so that an operator can easily understand and realize the switching; working parameters in the whole test method can be adjusted according to actual requirements, so that the method has high universality.

Description of the drawings:

FIG. 1 is a structural block diagram of a random test method of a vehicle door durability test bed based on a servo electric cylinder.

FIG. 2 is a specific working flow chart of a random testing method of a vehicle door durability testing stand based on a servo electric cylinder.

The reference numbers are as follows: 1 denotes a velocity setpoint signal x, 2 denotes an integration element, 3 denotes a displacement setpoint signal y, 4 denotes a target position r, 5 denotes a saturator, 6 denotes a comparator, 7 denotes a multiplier, and 8 denotes a servo cylinder.

The specific implementation mode is as follows:

FIG. 1 is a structural block diagram of a random test method of a vehicle door endurance test bed based on a servo electric cylinder.

In fig. 1, 1 is a speed setting signal x, 2 is an integration element, 3 is a displacement setting signal y, 4 is a target position r, 5 is a saturator, 6 is a comparator, 7 is a multiplier, and 8 is a servo cylinder.

FIG. 2 is a specific working flow chart of a random testing method of a vehicle door durability testing table based on a servo electric cylinder.

A random test method of a vehicle door endurance test bed based on a servo electric cylinder comprises the following 3 steps:

the car door endurance test platform uses the servo electric cylinder 8 as an actuator to drive the car door to complete opening and closing work, and the working parameters are as follows: the test frequency is 5 times/min, the displacement is 0m when the vehicle door is not opened, the displacement of the servo electric cylinder 8 driving the vehicle door to move is 1m, the speed of the servo electric cylinder 8 driving the vehicle door to move is 1m/s-4m/s, and all working parameters in the test bed can be automatically adjusted according to actual needs.

Step 1, generating and outputting a speed given signal x 1: the speed given signal x 1 comprises a speed part and a speed direction part, the servo electric cylinder 8 is used as an actuator, the servo electric cylinder 8 has high precision and high response speed, so that the speed adopts a random signal which is distributed normally at 1m/s-4m/s as the speed of the automobile door endurance test, and the sampling period of the random signal is 12 s; the durability test of the primary vehicle door comprises two actions of opening and closing the door, and the speed in the two processes is the same and the direction is opposite, so that a square wave signal with the amplitude of 1, the period of 12s and the duty ratio of 50 percent is adopted in the speed direction; the speed magnitude signal and the speed direction signal are used as the input of a multiplier, and the output is a speed given signal x 1;

step 2, outputting a displacement given signal y 3: different from the speed signal design, if the displacement signal directly adopts the target position r4, a large error is generated in the position control process, so that the position controller outputs a large error, and further speed control is influenced, in order to avoid the problem, the displacement given signal y 3 is obtained by adopting a speed given signal x 1 integration mode, so that the error in the position tracking process is ensured to be small, and meanwhile, the problem of considering the displacement direction is also avoided;

and step 3, switching of speed control and position control: the one-time vehicle door endurance test comprises four stages of vehicle door opening, holding, closing and holding, wherein the total time is 12s, the first 6s finishes the two stages of opening and holding, the second 6s finishes the two stages of closing and holding, the speed control plays a main role in the opening and closing stages, a target position r4 signal adopts a pulse signal with the period of 12s, the amplitude of 1m and the duty ratio of 50%, and when the displacement of opening and closing reaches the target position r, the holding stage is entered, and the position control plays a main role at the moment; the switching of position control and speed control is completed through a comparator 6 and a multiplier 7, a displacement given signal is processed by a displacement saturator 5, the lower limit of the displacement saturator 5 is 0m, the upper limit of the displacement saturator 5 is 1m, the difference between a target position r4 and the output signal of the displacement saturator 5 is used as the input of the comparator 6, 1 is output when the difference is not zero, and 0 is output when the difference is zero; the output of the comparator 6 and the speed given signal x 1 are used as the input of the multiplier 7, in the process of opening and closing the vehicle door, the displacement given signal y 3 does not reach the target position r4, at the moment, the comparator 6 outputs 1, the multiplier 7 outputs the speed given signal x 1, at the moment, the speed control plays a main role, at the keeping stage, the displacement given signal y 3 reaches the target position r4, at the moment, the comparator 6 outputs 0, the multiplier 7 outputs 0, at the moment, the position control plays a main role, the position accuracy is ensured, and the vehicle door is prevented from continuing to open or close when the displacement reaches the target position.

Claims

1. A random test method for a vehicle door durability test bed based on a servo electric cylinder is characterized in that the vehicle door durability test bed uses the servo electric cylinder as an actuator to drive a vehicle door to complete opening and closing work, and working parameters are as follows: the test frequency is 5 times/min, the displacement is 0m when the vehicle door is not opened, the displacement of the servo electric cylinder driving the vehicle door to move is 1m, the speed of the servo electric cylinder driving the vehicle door to move is 1m/s-4m/s, and the test frequency, the displacement when the vehicle door is not opened and the working parameters of the displacement 3 of the servo electric cylinder driving the vehicle door to move can be automatically adjusted according to actual needs; the random test method for the vehicle door durability test bed based on the servo electric cylinder is characterized by comprising the following steps:

step 1, generating and outputting a speed given signal x: the speed given signal x comprises a speed part and a speed direction part, a servo electric cylinder is used as an actuator, a random signal which is in standard normal distribution at the speed of 1-4 m/s is used as the speed of the vehicle door endurance test, and the sampling period of the random signal is 12 s; the durability test of the primary vehicle door comprises two actions of opening and closing the door, and the speed in the two processes is the same and the direction is opposite, so that a square wave signal with the amplitude of 1, the period of 12s and the duty ratio of 50 percent is adopted in the speed direction; the speed magnitude signal and the speed direction signal are used as the input of a multiplier, and the output is a speed given signal x;

step 2, outputting a displacement given signal y: the displacement given signal y is obtained by adopting a speed given signal x integration mode;

and step 3, switching of speed control and position control: the one-time vehicle door endurance test comprises four stages of vehicle door opening, holding, closing and holding, wherein the total time is 12s, the first 6s finishes the two stages of opening and holding, the second 6s finishes the two stages of closing and holding, the speed control plays a main role in the opening and closing stages, a target position r signal adopts a pulse signal with the period of 12s, the amplitude of 1m and the duty ratio of 50%, and when the displacement of opening and closing reaches the target position r, the vehicle door enters the holding stage, and the position control plays a main role at the moment; the switching of position control and speed control is completed through a comparator and a multiplier, a displacement given signal is processed by a displacement saturator, the lower limit of the displacement saturator is 0m, the upper limit of the displacement saturator is 1m, the difference between a target position r and an output signal of the displacement saturator is used as the input of the comparator, 1 is output when the difference is not zero, and 0 is output when the difference is zero; the output of the comparator and the speed given signal are used as the input of the multiplier, in the opening and closing process of the vehicle door, the displacement given signal y does not reach the target position r, at the moment, the comparator outputs 1, the multiplier outputs the speed given signal, at the moment, the speed control plays a main role, at the keeping stage, the displacement given signal y reaches the target position r, at the moment, the comparator outputs 0, the multiplier outputs 0, and at the moment, the position control plays a main role.