JPH0365629A - Method for operating experimental apparatus of collision of vehicle - Google Patents

Abstract

PURPOSE:To enable collision of a vehicle to be tested at a highly accurate speed of collision by switching a control of a motor from a drive force control over to a speed control automatically when a value near an aimed speed set beforehand is reached. CONSTITUTION:First a desired traction value of a traction rope is set according to test conditions such as the weight of a vehicle to be tested, an aimed speed of collision, etc., and then a current control of a motor is conducted so that the traction value can be obtained. At an initial time point of running, on the other side, a fixed-speed transition curve Vc for the vehicle to be tested is set beforehand on the basis of the characteristics and elongation amount of the traction rope, an acceleration inertia amount, a running resistance value of the whole of a system at the aimed speed of collision, etc., and when the speed of the motor reaches a preset value V1 near the aimed speed on the fixed-speed transition curve Vc, the control of the motor is switched automatically from a drive force control to a speed control by an electric or electronic circuit having a detecting circuit. Thereby the vehicle to be tested can be made to collide with an object at a highly accurate speed of collision.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention accelerates a vehicle under test by driving a towing rope winding drum with an electric motor and winding up the towing rope to reach a predetermined position. The present invention relates to a method of operating a vehicle collision test apparatus, in which the collision between the vehicle under test and a tow rope is broken at the time when the vehicle under test is coasted and the vehicle under test collides with a target object.

``Prior Art'' In general, vehicle collision test equipment is used to tow a heavy vehicle and accelerate it to high speeds, but the length of the acceleration path is limited in terms of equipment. , a fairly rapid acceleration is often required. As a result, the rope that pulls the vehicle under test naturally has a corresponding strength, and its rigidity is also quite high.

However, the length of the towing rope in high-speed collision test equipment is usually such that the sending out and winding drums of the rope are located in the same place, so the length of the towing rope in front of the vehicle is Even if we consider only the length, it can reach anywhere from several hundred meters to a thousand meters.

Therefore, when the tension necessary to tow and accelerate the vehicle under test is applied to the tow rope, the amount of elongation is extremely large, sometimes reaching several meters. Moreover,
This amount of elongation will change as a result of changes in the torque of the driving machine, in other words, the tension applied to the traction rope.

Therefore, the length of the rope wound is not always equal to the distance traveled by the vehicle under test, and the difference between them, the amount of rope elongation, changes as the traction force changes, so the length of the rope wound It is unreasonable to estimate the vehicle's position based on the speed of the vehicle, or to consider the speed at which the rope is wound as the speed of the vehicle.

Then, so that the stretch of the rope will hardly be a problem,
I wonder if it would be better to significantly increase the rigidity of the tow rope.
If the tow rope is made thicker to increase its rigidity, the outer diameter of the winding drum and the winding pitch will become larger, and the diameter of the sheep, etc. for changing the direction of the tow rope must also be increased.

Therefore, the size of the machine inevitably increases, which not only impairs the economic efficiency of the machine itself, but also causes a large increase in the drive output due to an increase in the amount of acceleration inertia of the mechanical system such as the winding drum, making it extremely redundant and complicated. It becomes an uneconomical facility.

Furthermore, since the vehicle under test has a large amount of inertia,
Dynamically, a water system can be thought of as a weight attached to the end of a long spring, and the elastic body (the towing rope) and the inertial body (the vehicle under test) interact with each other, causing vibrations. It turns out. As a result, when the acceleration changes, the vehicle travels while pulsating at a very low frequency, making it even more difficult to precisely adjust its speed to a desired speed.

In order to solve this problem, when the acceleration changes like this (at the start of acceleration and when transitioning to constant speed), we have developed a method of changing the tension in a transitional curve instead of applying the necessary tension change all at once, and a method that changes the tension at the point of separation. Methods such as keeping a constant tension on the rope at all times have been adopted up to this point. However, a common problem with these methods is that the drive machine controls the speed during the acceleration period, and all of them do not take into account the elongation of the rope. The method consists in estimating the vehicle's position or regarding the winding speed of the rope as the speed of the vehicle under test, and then giving a speed command value based on that position or speed.

In other words, if the amount of stretch of the rope changes, the above method will naturally have errors in judgment, especially if the rope starts to vibrate.
It becomes very difficult to match the speed of the vehicle under test to the target value. For example, the invention disclosed in Japanese Patent Application Laid-Open No. 62-12833 aims to reduce the acceleration to zero at the departure point, but as mentioned earlier, there is Since there is an elastic body called a rope, zero acceleration of the electric motor does not necessarily equal zero acceleration of the vehicle under test. Therefore, in order to reduce the acceleration of the test vehicle to zero using such a method, it is necessary to provide a long constant speed running section that is long enough to stabilize the transient state of the rope, or to take into account the dynamic behavior of the rope. It is necessary to create a constant speed transition curve that is much gentler than that.

However, although it is possible to reduce the acceleration to exactly zero at the breakaway point by adopting any of the above methods, considering the nature of the collision test equipment, it is necessary to conduct a test run in advance to reduce the running resistance of the system. It is difficult to measure the dynamic behavior characteristics of
Therefore, especially in facilities where the type of vehicle under test is not limited, the calculation of the speed pattern must be a curve with a gentle constant speed transition curve that allows for a considerable margin. This results in an increase in the length of the acceleration travel path, which inevitably impairs economic efficiency.

Therefore, in view of the above-mentioned problems, the inventor of the present invention drives the winding drum of the tow rope at N**, and disconnects the tow rope when the vehicle under test reaches a predetermined speed. In the method of operating a vehicle collision test apparatus in which a test vehicle is caused to collide with an object by coasting, an embodiment as shown in FIG. 3 was proposed (Japanese Patent Laid-Open No. 1-165925).

That is, the passage of a moving object is detected at least on the acceleration travel path at the starting point of the test vehicle C or at a point tl where the speed of the test vehicle near the starting point is extremely low, and on the acceleration travel path at a point tp2 in a relatively low speed range. These detection points tpl, tp2
The driving force of the electric motor is determined by measurement or calculation, and the length of the traction rope wound around the winding drum between the detection points is measured. From this, the running resistance of the entire system and the damped vibration phenomenon of the traction rope are determined. The present invention is a method of operating a vehicle collision test apparatus, which is characterized in that an optimum acceleration curve is determined by estimation, and thereafter the electric motor is operated in accordance with this curve.

Therefore, the purpose of this driving method is to obtain multiple detection points from or near the starting point of the vehicle under test, and ultimately to match the speed of the vehicle under test to a predetermined target speed as much as possible. However, this invention is based on a general concept or a prerequisite concept, and even though the optimum acceleration curve has been determined using the above-mentioned configuration, it is necessary to automatically break the connection between the tow rope and the vehicle under test by time tc. Able to achieve the above objectives
However, this does not mean that it is possible to get as close as possible to the above objective.

``Problems to be solved by the present invention'' ■ In this type of conventional driving method, as mentioned above, the amount of stretch of the towing rope changes, and the speed of the test vehicle is accelerated to match the target value. When shifting to a more constant speed, the tow rope began to vibrate, which caused the actual vehicle speed to not match the winding drum speed, making it impossible to accurately match the test vehicle's speed to the target value. There was a drawback that there was no

(2) Also, in the embodiment proposed by the present inventor earlier, there was no specific method for automatically adjusting the speed of the test vehicle to the target value midway through the test.

Therefore, in view of the above-mentioned problems ① and ②, the present invention accurately adjusts the speed of the vehicle under test to a predetermined value when the speed of the winding drum rotated by the driving force of the electric motor reaches a predetermined value. To obtain a method for operating a vehicle collision test apparatus that can stabilize the vehicle under test and thus allow a vehicle under test to collide with a target object at a highly accurate collision speed.

"Means for Solving the Problems" The main points of the present invention are, first of all, the expansion and contraction of the rope when the acceleration of the test vehicle changes, which was overlooked in the above-mentioned prior art, or in other words, when the tension of the towing rope changes. The focus is on exercise. In other words, consider the tow rope as an elastic body,
The amount of elongation is measured at the initial point of travel, and in order to prevent this amount of elongation from changing during subsequent travel, acceleration is performed by a fixed amount of gravitational force.

Next, as a second point, in order to finally adjust the vehicle speed to the target value, for example, after reaching close to the target speed,
The control method is switched to speed control in order to accurately match the speed to the target value.

Therefore, the method of operating the vehicle collision test apparatus of the present invention is as follows:
An electric motor drives the winding drum for the towing rope that pulls the vehicle under test, and when the vehicle under test reaches a predetermined speed, the connection to the rope is cut off, causing the vehicle to coast and collide with the object. In the operating method of the vehicle collision test equipment, first, the desired traction force value of the traction rope is set according to test conditions such as the weight of the vehicle to be tested and the target collision speed, and then the traction force value is obtained. On the other hand, at the initial stage of running, the constant speed of the vehicle under test is determined in advance based on the characteristics of the traction rope, the amount of stretch, the amount of acceleration inertia, and the running resistance value of the entire system at the target collision speed. A transition curve is set, and the speed of the electric motor reaches a value near a preset target speed on the constant speed transition curve (
), the motor control is automatically switched from driving force control to speed i and If control by an electric or electronic circuit having a detection circuit. 1 In addition, when the speed transition curve is set as described above, - the electric power e which makes the window power the target ε! When the speed command value of the constant speed transition curve is lower than the speed of the control result at t1, an electric or electronic circuit having a comparison circuit changes the control of the motor from the driving force weight, i weight, and il. It may also be possible to automatically switch to speed control.

“Example J Drawings about examples? Refer to and explain.

First, the present invention uses an electric motor to drive the winding drum of the towing rope, and when the vehicle under test reaches a speed of E, the connection with the traction rope is cut off, and the vehicle under test is coasted. It is assumed that you know how to operate a collision test device for a vehicle that is hit by an object.

Therefore, FIG. 16 and FIG.
: Current i of the electric motor on the winding lid side that winds the l-p! J
In the "time (horizontal x) - motor and vehicle speed under test (vertical @ Y)" curve of the method of performing control, -window section/power aL ÷] test medium speed 2, branch line V rr + is electric motor 1
The dotted line VC indicates the G speed of the vehicle under test.
tC is the time when the engagement between the tow rope and the vehicle under test C is severed;
p2 is an acceleration method! 1 Test vehicle I] body or tow platform 1 on the road! This is the time when a moving object passes through the detector. below,
Taking up the case where the drive motor is a DC shunt motor, which is common in large-scale crash test equipment, the method will be explained in the order in which the test is actually performed.

First, a desired traction force value of the traction force is set based on test conditions such as M repulsion and collision target speed of the test I$i vehicle C.

Next, acceleration is started according to a rise curve that has been set in advance so that the traction force value can be obtained, and the test vehicle C is accelerated to the target speed while controlling the current of the electric motor. At this time, at least a point at or near the starting point where the speed and current value of the tested vehicle C is extremely low (tpl point), and a relatively low speed region where the rising curve has ended and acceleration is being performed with a constant driving force value. At point (tp2), a passage detector for a moving object such as a vehicle under test or a tow platform II (dolly) is installed, and the winding length of the rope is measured while the moving object C travels between two points (trl, tl). By measuring this and comparing this with the actual distance between the two points tpl and tp, the length of extension of the rope until the electric motor produces the specified driving force is measured. Then, in order not to change this amount of elongation,
The electric motor continues to accelerate with constant driving force.

On the other hand, the characteristics and amount of stretch of the towing rope are determined at the initial stage of running.
The constant speed transition curve Va of the vehicle under test C is calculated in advance from the acceleration inertia of the mechanical system, the running resistance value of the entire system at the collision target speed, etc. Note that this constant speed transition curve Va changes the speed of the vehicle under test C to a target speed, for example, 1
In order to adjust to 00Fa/h, the spring constant and damping constant (these are known or obtained through prior experiments) of the drag bow 10-b are set in advance. It can be set by finding the critical damping condition of this damped vibration system.

Therefore, in the embodiment of FIG. When the speed of the motor reaches a speed value near a preset target speed Vl of the constant speed transition curve Va, the control of the motor is automatically changed from driving force control to speed control by an electric or electronic circuit having a detection circuit. In the embodiment shown in FIG. 2, the speed command value of the constant speed transition curve va becomes lower than the speed of the control result of the electric motor aiming at a constant driving force. When the speed reaches the constant speed transition curve Va, the motor control is automatically switched from the driving force control to the speed ￥AwJ by an electric or electronic circuit having a comparison circuit, so that the speed of the test vehicle C rides on the constant speed transition curve Va or reaches an infinite speed. The closer you get to it, the older it gets.

In addition, vm' is the speed curve of the motor assuming that it does not transfer to the constant speed transition curve, and tl is the time when the speed of the motor reaches the II lit switching speed value near the preset target speed. t2 is the initial −・r
The speed command value of the constant speed transition curve Va is lower than the speed of the control result of the electric motor that uses the driving force as the [] pole; 7L
It is the time when

``Effect 1 of the present invention As is clear from the explanation below in 1-Xq'j, in the present invention, the constant speed transition curve of the test vehicle is set in advance at the initial point of driving. , 7 This is set as the speed control target of the electric tester, and after a certain point when the speed of the electric motor approaches the speed control target, the speed target cylinder is placed on the constant speed transition curve, and the iti control method of the electric motor is changed to the driving force. Automatically switches from control to speed control, making it easy to match the desired target value when disconnecting the vehicle under test from the tow rope.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 show an embodiment of the present invention at "time t(
(horizontal axis) to speed ■ (vertical axis)” each explanatory diagram based on the curve, 3rd
The figure is an explanatory diagram based on the same curve showing a conventional example. C...Vehicle under test, tpl, tp2...Time of detection, tc...Time of disconnection between the tow port and the vehicle under test, Vm...Speed curve of the motor, ■e・...Speed curve of the vehicle under test, VC...Constant speed transition curve,

Claims (1)

[Claims] 1) A winding drum for a tow rope that pulls the vehicle under test is driven by an electric motor, and when the vehicle under test reaches a predetermined speed, the connection with the tow rope is cut off, and the vehicle under test is In the method of operating a vehicle collision test device in which a vehicle collides with a target object by coasting, the desired traction force value of the towing rope is first set according to test conditions such as the weight of the vehicle to be tested and the target collision speed, and then the The current of the electric motor is controlled so that the traction force value can be obtained, and at the beginning of the run, the characteristics of the traction rope, the amount of elongation, the amount of acceleration inertia, the running resistance value of the entire system at the target collision speed, etc. A constant speed transition curve of the vehicle under test is set in advance from the above, and when the speed of the electric motor reaches a value near a preset target speed on the constant speed transition curve, an electric or electronic circuit having a detection circuit, A method of operating a vehicle collision experiment apparatus, characterized in that control of an electric motor automatically switches from driving force control to speed control. 2) An electric motor drives the winding drum of the tow rope that pulls the vehicle under test, and when the vehicle under test reaches a predetermined speed, the connection with the tow rope is cut off, and the vehicle under test coasts toward the object. In the operating method of the collision test device for vehicles to be collided, first, a desired traction force value of the traction rope is set according to test conditions such as the weight of the vehicle to be tested and the target collision speed, and then the traction force value is obtained. The electric current of the electric motor is controlled to ensure that the vehicle under test is properly controlled at the initial stage of driving, and the characteristics of the vehicle under test are determined in advance based on the characteristics of the towing rope, the amount of stretch, the amount of acceleration inertia, and the running resistance value of the entire system at the target collision speed. A constant speed transition curve is set, and when the speed command value of the constant speed transition curve is lower than the speed of the motor control result with a constant driving force as the target, an electric or electronic circuit having a comparison circuit controls the motor. A method of operating a vehicle collision experiment device, characterized in that control automatically switches from driving force control to speed control.