CN108489735A - Double trailer train model stability experimental rig based on the theory of similarity and method - Google Patents

Abstract

The invention relates to a model stability test device and method for a double-trailer car train based on similarity theory. The test device consists of a model movement part and a data acquisition and processing part. The model movement part includes the double-trailer train vehicle model and the free combination board, and the data acquisition and processing part includes attitude measurement sensors, satellite positioning devices, wireless network transceivers, smart phones and laptop computers. The test method is as follows: (1) road models of different forms of freely combined plate structure for the operation of the double-trailer train vehicle model; (2) using the remote control to control the driving motor to make the double-trailer train vehicle model run; (3) attitude measurement sensor and satellite positioning device Collect the running data of the vehicle model in real time, and transmit the running data to the smart phone and/or laptop through the wireless network transceiver. (iv) Process and analyze the operating data of the model, and deduce the operating data corresponding to the actual vehicle. The invention is used for testing and researching the stability of a double-trailer car train.

Description

Device and method for model stability test of double-trailer train based on similarity theory

technical field

The invention belongs to the technical field of test equipment, and relates to a test device and method for the stability of a double-trailer train model based on similarity theory.

Background technique

The lateral stability test of automobile trains refers to GB/T 25979-2010/ISO 14791:2000 "Test Method for Lateral Stability of Road Vehicles, Heavy Commercial Vehicle Trains and Articulated Passenger Cars" and GB/T 26778-2011 "Performance Requirements and Test Methods for Automobile Trains" "conduct. The ratio of the peak value of the motion variable of the vehicle unit model of the follower car to the peak value of the motion variable of the vehicle unit model of the first car during the prescribed driving operation of the double-trailer train. The lateral offset between the centerline point trajectory of the front axle of the vehicle and the point trajectory of other parts of the vehicle. In the single lane change test, measure the distance between the centerline point trajectory of the front axle and the axis centerline point trajectory with the largest deviation from the vehicle unit model trajectory of the last vehicle. The lateral displacement of is used to determine the instantaneous trajectory offset and the maximum trajectory offset. If the vehicle unit model trajectory of the last vehicle does not "overshoot" the vehicle unit model trajectory of the first vehicle, record the maximum "undershoot" amount. The specific requirements for the straight-line running stability of a double-trailer car train are: the maximum swing range of the rear axle center of the trailer relative to the traction axle center, the drawbar car train is not greater than 200mm, and the articulated car train (including the central axle trailer train) is not more than 100mm. The lateral stability test of a double-trailer car train is a dangerous extreme working condition. The whole car is long and takes up a lot of space, so it is difficult to conduct a real car test on a large scale on the road.

Contents of the invention

The purpose of the present invention is to provide a model stability test device and method for double-trailer trains based on similarity theory, so as to facilitate the research on the stability of double-trailer trains, provide reference for the structural improvement of double-trailer trains, and shorten the test period , improve the stability and safety of vehicle operation.

The technical scheme of the present invention is: a test device for the stability of a double-trailer train model based on the similarity theory, which is composed of a model movement part and a data acquisition and processing part constructed according to the similarity theory. The moving part of the model includes the vehicle model of the tractor, the vehicle model of the first section of the flatbed semi-trailer, the model of the traction trailer, the vehicle model of the second section of the flatbed semi-trailer and free combination plates, and different forms of road models are constructed from the free combination plates for dual Hanging car train vehicle model running. The data acquisition and processing part includes attitude measurement sensors, satellite locators, wireless network transceivers, smart phones and laptop computers. The attitude measurement sensor and the satellite locator are respectively placed on the center of mass of the vehicle model of the tractor, the vehicle model of the first section of the flatbed semi-trailer, the model of the traction trailer, and the vehicle model of the second section of the flatbed semitrailer. The attitude measuring sensors and the satellite locators of the above-mentioned vehicle models are connected to the wireless network transceiver, and the wireless network transceiver communicates with the smart phone and the computer through the wireless network.

The ratio of the actual vehicle size to the vehicle model size is: k _L = L _R / L _M , where:

L _R : actual vehicle size;

L _M : the corresponding vehicle model size;

k _L : the ratio of the actual vehicle size to the corresponding vehicle model size; the value range of k _L is 2-100.

The real vehicle is the tractor, the first flatbed semi-trailer, the traction trailer and the second flatbed semitrailer, and the vehicle models are the tractor vehicle model, the first flatbed semitrailer vehicle model, the traction trailer and the second flatbed Semi-trailer vehicle model.

According to the similarity theory, the adhesion coefficient of the pavement model is constructed, and the surface of the freely combined plate is coated and treated to construct different types of pavement models. The ratio of the adhesion coefficient of the road surface in the real vehicle test to the adhesion coefficient of the road surface model is:

kμ , the ratio of the adhesion coefficient of the road surface in the real vehicle test to the adhesion coefficient of the road surface model constructed based on the similarity theory;

μ _R , the adhesion coefficient of the road surface in the real vehicle test;

μ _M , the adhesion coefficient of the pavement model.

The pavement model is a sand material coating layer to simulate a gravel road surface, a waxy material coating layer to simulate a smooth road surface with low adhesion, a transparent resin material coating layer to simulate an icy road surface, or a corrugated core coating layer to simulate a rough road surface , does not exclude other types of pavement. The adhesion coefficient is the friction coefficient between the tire and the road surface, that is, the ratio of the tire adhesion to the tire normal force, μ = Fμ / Fz , where: μ is the adhesion coefficient, Fμ is the tire adhesion, Fz is the tire normal force . The above data are available in the open literature.

The ratio of the length of the pavement in the actual vehicle test to the length of the pavement model of the freely combined plate structure k s = L r / L b, where:

L r: the length of the road surface in the real vehicle test, unit: m;

L b: pavement model length of freely combined slab structure, unit: m;

k s: the ratio of the length of the pavement in the actual vehicle test to the length of the pavement model of the freely combined plate structure, and the value range of k _S is 2 to 100.

The lower part of the freely combined board is provided with feet for adjusting the angle of inclination, for adjusting the angle of inclination of the road surface model, and constructing road surfaces with different longitudinal slopes and transverse slopes in reality. The test device is provided with a remote controller, and the vehicle model of the tractor is provided with a motor controller, a steering drive motor and a speed adjustment drive motor, the remote controller communicates with the motor controller, and the motor controller is connected with the steering drive motor and the speed adjustment drive motor circuit.

The present invention is based on the model stability test method of double-trailer car train of similar theory, and process comprises:

(1) According to the test requirements, different types of pavement models are constructed from freely combined plates for the operation of the double-trailer train vehicle models;

(2) Use the remote control to control the steering drive motor and the speed adjustment drive motor, so that the vehicle model of the double-trailer train vehicle whose proportional coefficient is reduced according to the similar theory turns, starts, accelerates, decelerates, maintains a constant speed and/or stops;

(3) The attitude measurement sensor and the satellite locator placed on the vehicle model of the double-trailer train collect the operating data of the model in real time, and transmit the operating data to the smart phone and/or laptop computer through the wireless network transceiver; the smart phone and/or laptop computer pass through The wireless network transceiver controls the attitude measurement sensor and the satellite locator to start or stop collecting operation data;

(iv) Smartphones and portable computers process and analyze model operating data, derive corresponding real vehicle operating data based on similarity theory, and output model operating data and real vehicle operating data results.

The running data are the acceleration a _M , angular velocity ω _M , angle ϕ _M , driving trajectory s _M and driving speed v _M of each vehicle model. The attitude measurement sensor measures the acceleration, angular velocity and angle of each vehicle model, and the satellite positioning device records the driving trajectory and speed of each vehicle model. Based on the similarity theory, the calculation formula for deriving the corresponding real vehicle operating data from the model operating data is:

a _R = ka*a _M

ω _R = kω*ω _M

ϕ _R = k _ϕ *ϕ _M

s _R = k s *s _M

v _R = kv*v _M

In the formula:

a _R , ω _R , ϕ _R , s _R , v _R are the acceleration, angular velocity, angle, driving trajectory and driving speed of the real vehicle, respectively. ka , kω , k _ϕ , k s and kv are the acceleration ratio, angular velocity ratio, angle ratio, driving trajectory ratio and driving speed ratio of the real vehicle and the vehicle model, respectively. The values of ka , kω , k _ϕ , k s and kv range from 1 to 100.

The device and method for testing the model stability of a double-trailer train model based on similarity theory in the present invention combine the model movement part with the data acquisition and processing part to realize the test and research on the lateral running stability of the double-trailer train, and to improve the stability of the double-trailer train. The lateral stability of automobile trains provides a reference scheme, which is beneficial to reduce the test cost and shorten the test period. The cost of the test device is low, it is easy to purchase accessories or assemble and manufacture, the test process is simple to operate, and the data collection is accurate and reliable, which is conducive to providing reference for the structural design and improvement of double-trailer trains, and improving the stability and safety of vehicle operation.

Description of drawings

Fig. 1 is the schematic diagram of the moving part of the double-trailer train model stability test device based on the similarity theory;

Fig. 2 is the connection diagram of data collection and processing part;

Fig. 3 is the schematic diagram of the remote control of the steering drive motor and the speed adjustment drive motor;

Fig. 4 is the schematic flow sheet of the present invention's method for stability test of double-trailer train model based on similarity theory;

Among them: 1—tractor vehicle model, 2—the first flatbed semi-trailer vehicle model, 3—traction trailer model, 4—the second flatbed semitrailer vehicle model, 5—attitude measurement sensor, 6—satellite locator, 7—free combination board; 8—remote controller.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments and the accompanying drawings. The protection scope of the present invention is not limited to the embodiments, and any changes made by those skilled in the art within the scope defined in the claims also belong to the protection scope of the present invention.

The present invention is based on the similarity theory, and the double-trailer train model stability test device is composed of a model movement part and a data acquisition and processing part constructed according to the similarity theory. As shown in Figure 1, the moving part of the model includes the tractor vehicle model 1, the first flatbed semi-trailer vehicle model 2, the traction trailer model 3, the second flatbed semitrailer vehicle model 4 and the free combination plate 7, which are composed of free The combined plate 7 constructs road models of different forms for the operation of the double-trailer train vehicle models. As shown in Figure 2, the data acquisition and processing part includes attitude measurement sensor 5, satellite positioning device 6, wireless network transceiver, smart phone and portable computer. Select the model of the attitude measurement sensor: JY61, the model of the satellite locator 6: MK16S, the model of the wireless network transceiver: G41 (the wireless network transceiver can be replaced by a wireless network receiver, a wireless network transmitter (wireless router), and both in practice Can receive and transmit wireless network WiFi signal and 360 portable WiFi USB). The attitude measurement sensor 5 and the satellite locator 6 are respectively placed on the centroids of the tractor vehicle model 1, the first flat semi-trailer vehicle model 2, the traction trailer model 3 and the second flat semi-trailer vehicle model 4. The centroid is the center of mass of the vehicle model. The attitude measurement sensor 5 and the satellite locator 6 of the tractor vehicle model 1, the first flat semi-trailer vehicle model 2, the traction trailer model 3 and the second flat semi-trailer vehicle model 4 are connected to the wireless network transceiver, and the wireless network The transceiver communicates with smartphones and computers via a wireless network. As shown in Figure 3, the test device is provided with a remote controller 8, and the tractor vehicle model 1 is provided with a motor controller, a steering drive motor and a speed adjustment drive motor, the remote controller is connected with the motor controller in communication, and the motor controller is connected with the steering drive motor Connect with the speed adjustment drive motor circuit. The remote controller 8 independently controls two drive motors, the steering drive motor can control the steering of the tractor vehicle model 1, the speed adjustment drive motor can control the start, acceleration, deceleration, constant speed and stop of the tractor vehicle model 1, and then control the tractor vehicle The operating states of vehicle model 1, vehicle model 2 of the first flatbed semi-trailer, model 3 of the tractor trailer, and vehicle model 4 of the second flatbed semitrailer are in line with the operating conditions of the actual vehicle.

According to the adhesion coefficient of the road surface in the actual vehicle test, the adhesion coefficient of the road surface model is calculated by using the relational expression kμ = μ _R / μ _M between the adhesion coefficient of the road surface in the actual vehicle test and the adhesion coefficient of the road surface model. According to the calculated adhesion coefficient of the road surface model, find out the material corresponding to the adhesion coefficient of the road surface model from the literature ("Automotive Theory", edited by Cui Shengmin, Peking University Press, 2016), and then coat the surface of the free combination plate 7 and processing to construct different types of pavement models. The coating layer of sand material is used to simulate gravel road surface, the coating layer of waxy material is used to simulate smooth road surface with low adhesion, the coating layer of transparent resin material is used to simulate icy road surface or the coating layer of corrugated paper core is used to simulate uneven road surface. The lower part of the free combination board is provided with pads, which are used to adjust the inclination angle, and construct road surfaces with different longitudinal slopes and transverse slopes in reality.

The ratio of the actual vehicle size to the vehicle model size is: k _L = L _R / L _M , where:

L _R : actual vehicle size;

L _M : the corresponding vehicle model size;

k _L : the ratio of the actual vehicle size to the corresponding vehicle model size;

In the actual vehicle test, the ratio of the length of the road surface to the length of the structure of the freely combined plate 1 k s = L r / L b,

In the formula:

L r: the length of the road surface in the real vehicle test, unit: m;

L b: pavement model length of freely combined slab structure, unit: m;

k s: the ratio of the pavement length in the actual vehicle test to the pavement model length of the freely combined plate structure;

In this embodiment, the selected value of k _L and selected k s is 10, that is, the model is one-tenth of the actual vehicle.

Based on the similarity theory, the stability test method of the double-trailer car train model is shown in Figure 4, and the process is as follows:

(1) According to the test requirements, different types of pavement models are constructed by the free combination plate 7, which is used for the operation of the double-trailer train vehicle model;

(2) Utilize the remote controller 8 to control the steering drive motor and the speed adjustment drive motor, so that the vehicle model of the double-trailer train vehicle whose proportional coefficient is reduced according to the similarity theory can be steered, started, accelerated, decelerated, kept at a constant speed or stopped;

(3) The attitude measurement sensor 5 and the satellite positioning device 6 placed on the double-trailer train vehicle model collect the running data of the double-trailer train vehicle model in real time, and the running data includes acceleration, angular velocity, angle, running track and running speed. The attitude measurement sensor 5 measures the acceleration, angular velocity and angle of the model, and the satellite positioning device 6 records the driving track and the driving speed of the model. Transmit the operation data to the smart phone and/or laptop through the wireless network transceiver, and the smart phone and/or laptop control the attitude measurement sensor and the satellite locator to start or stop collecting the operation data through the wireless network transceiver;

(iv) The smart phone and laptop computer process and analyze the model operation data, deduce the corresponding real vehicle operation data based on the similarity theory, and output the model operation data and the actual vehicle operation data results. The derivation formula is:

a _R = ka*a _M

ω _R = kω*ω _M

ϕ _R = k _ϕ *ϕ _M

s _R = k s *s _M

v _R = kv*v _M

where:;

a _R , ω _R , ϕ _R , s _R , v _R are the acceleration, angular velocity, angle, driving trajectory and driving speed of the real vehicle respectively; a _M , ω _M , ϕ _M , s _M and v _M are the Acceleration, angular velocity, angle, driving trajectory and driving speed; ka , kω , k _ϕ , k s , kv are the acceleration ratio, angular velocity ratio, angle ratio, driving trajectory ratio and driving speed ratio of the real vehicle and the vehicle model, respectively.

In the specific real vehicle test, the speed and displacement of the real vehicle are predetermined, and the speed and route required by the real vehicle are set according to the purpose of the test, so that the speed and route of the real vehicle can be approximated. After the real vehicle test is completed, Various data are measured by instruments, including but not limited to various vehicle parameters, such as speed and displacement. The speed of the vehicle model can be controlled by speed regulating drive motors.

The derivation of the similarity model related formula is:

(1) In the real vehicle test, the real vehicle speed, displacement and required time are recorded as v _R , s _R and t _R respectively;

⑵In the vehicle model test, the displacement is recorded as s _M , the time is recorded as t _M , and the displacement is recorded as ν _M . The displacement scale coefficient of the test vehicle model is k _S , the time scale coefficient is k t , the velocity scale coefficient is k v , the acceleration scale coefficient is k α , and the angular velocity scale coefficient is k ω .

(3) Obtain the correlation ratio coefficient between the real vehicle and the vehicle model

① Proportional coefficient of displacement

k _S = s _R / s _M , this is known (i.e. pre-determined)

② Estimation of actual vehicle running time:

t _R = s _R / v _R , where the displacement and velocity are pre-determined

③ The ratio coefficient of the running time of the real vehicle and the vehicle model can be estimated:

kt = t _R / t _M , where t _R is estimated and t _M is accurately measured in vehicle model tests. Then you can get:

④ The proportional coefficient of speed is:

Then, approximately consider the relationship between acceleration and displacement

⑤ The proportional coefficient of acceleration is:

Compared with the vehicle model, according to the geometric relationship and the triangle similarity theorem, it can be known that the steering angle of the front wheels of the tractor is consistent with the steering angle of the front wheels of the tractor vehicle model, that is, θ _R = θ _M

Therefore, the proportional coefficient of the angle is kθ =1

⑥ The proportional coefficient of angular velocity is:

So far, all the proportional coefficients have been deduced, and the proportional coefficients of other physical quantities can be deduced in this way.

Claims (10)

1. a kind of double trailer train model stability experimental rig based on the theory of similarity, it is characterized in that：The experimental rig It is made of with process part the model sport part constructed according to the theory of similarity and data acquisition；The model sport part includes Tractor auto model（1）, first segment flat bed trailer auto model（2）, traction drag platform model（3）, second section tablet semi-mounted Vehicle auto model（4）With free modular plate（7）, by free modular plate（7）Various forms of road surface models are constructed to hang for double Truck combination auto model is run；The data acquisition and procession part includes attitude-measuring sensor（5）, global positioning system （6）, wireless network transceiver, smart mobile phone and portable computer；The attitude-measuring sensor（5）And global positioning system（6） It is individually positioned in tractor auto model（1）, first segment flat bed trailer auto model（2）, traction drag platform model（3）With second Save flat bed trailer auto model（4）Barycenter；The attitude-measuring sensor of above-mentioned each auto model is connected with global positioning system To wireless network transceiver, wireless network transceiver is connect by wireless network with smart mobile phone and compunlcation.

2. the double trailer train model stability experimental rig according to claim 1 based on the theory of similarity, feature It is：Real vehicle size and the ratio of auto model size are：k _L =L _R/L _M, in formula：

L _R：Real vehicle size；

L _M：Corresponding auto model size；

k _L ：The ratio of real vehicle size and corresponding auto model size.

3. the double trailer train model stability experimental rig according to claim 1 based on the theory of similarity, feature It is：According to the attachment coefficient of theory of similarity construction road surface model, to free modular plate（7）Surface is coated and is handled, structure Make different types of road surface model.

4. the experimental rig of the double trailer train model stability according to claim 3 based on the theory of similarity, special Sign is：The road surface model is to simulate low attachment using sand class material coat simulation sand-gravel surface, wax material coat Smooth road, clear resinous materials coat simulation ice-patch surface or corrugating media coat simulate rough road surface.

5. the experimental rig of the double trailer train model stability according to claim 3 based on the theory of similarity, special Sign is：Road surface length and the free modular plate in real train test（1）The ratio of the road surface model length of construction is：ks=Lr/LB, in formula：

Lr：Road surface length in real train test, unit：m；

Lb：The road surface model length of free modular plate structure, unit：m；

ks：The ratio of road surface length and the road surface model length of free modular plate structure in real train test.

6. the double trailer train model stability experimental rig according to claim 3 based on the theory of similarity, feature It is：The free modular plate（7）Lower part be equipped with feet, the angle of inclination for adjusting road surface model, construction reality in not With the road surface of head fall and cross fall.

7. the double trailer train model stability experimental rig according to claim 1 based on the theory of similarity, feature It is：The experimental rig is equipped with remote controler（8）, the tractor auto model（1）Equipped with electric machine controller, turn to driving motor Driving motor is adjusted with speed, the remote controler is communicated to connect with electric machine controller, the electric machine controller and steering driving electricity Machine adjusts driving motor circuit with speed and connects.

8. a kind of examination of the double trailer train model stability experimental rig according to claim 1 based on the theory of similarity Proved recipe method, process include：

(i) according to test requirements document, by free modular plate（7）Various forms of road surface models are constructed, for double trailer train vehicle Model running；

(ii) remote controler is utilized（8）Manipulation turns to driving motor and speed adjusts driving motor, makes according to the proportional system of the theory of similarity Number reduce double trailer train auto model turn to, start, accelerate, slow down, at the uniform velocity and/or stop；

(iii) the attitude-measuring sensor being placed on double trailer train auto model（5）And global positioning system（6）Acquisition in real time The operation data of double trailer train auto model, and operation data is sent to by wireless network transceiver by smart mobile phone And/or portable computer；The smart mobile phone and/or portable computer control attitude measurement by wireless network transceiver and sense Device and global positioning system start or stop acquisition operation data；

(iv) the smart mobile phone and/or portable computer are handled and are analyzed to model running data, are based on the theory of similarity Derive the operation data of corresponding real vehicle, output model operation data and real vehicle vehicle operation data result.

9. the double trailer train model stability test method according to claim 8 based on the theory of similarity, feature It is：The operation data is the acceleration of each auto model（a _M）, angular speed（ω _M）, angle（ϕ _M）, driving trace（s _M）And row Sail speed（v _M）；The attitude-measuring sensor（5）Measure the acceleration, angular speed and angle of each auto model, the satellite Position indicator（6）Record the driving trace and travel speed of each auto model.

10. the double trailer train model stability test method according to claim 8 based on the theory of similarity, feature It is：Derive that the calculation formula of the operation data of corresponding real vehicle is by model running data based on the theory of similarity：

a _R=ka*a _M

ω _R=kω*ω _M

ϕ _R=k _ϕ *ϕ _M

s _R=ks*s _M

v _R=kv*v _M

In formula：

a _R、ω _R、ϕ _R、s _RWithv _RThe respectively acceleration of real vehicle, angular speed, angle, driving trace and travel speed；a _M、

ω _M、ϕ _M、s _MWithv _MFor the acceleration of each auto model, angular speed, angle, driving trace and travel speed；ka、kω、k _ϕ 、kS andkvRespectively the acceleration ratio of real vehicle and auto model, angular speed ratio, angle ratio, driving trace ratio and Travel speed ratio.