Vehicle crash test device

Abstract

To solve the problem that the vehicle speed deviates from a predetermined speed at a separation position of a vehicle by changing the traction speed of a motor according to the load amount on a traction motor near the completion of acceleration shifting from acceleration having a large influence on the traction speed to traction to the constant speed.SOLUTION: Disclosed is a vehicle collision test device which includes: a traction rope 1; a drum 2 for pulling the traction rope 1; a motor 4 for driving the drum 2; and control means 5 for controlling input of a torque command Tr to the motor 4 based on a traction speed command Vref, and performs a collision test by connecting a vehicle 7 to the traction rope 1 through a dolly 6 as connection / disconnection switching means. The control means 5 is configured to correct the traction speed command Vref of the motor 4 in the direction of reducing the load amount according to the load amount of the motor 4 at a predetermined timing near the completion of acceleration.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle collision test device capable of reducing the influence of the stretching and contraction of a towing rope during a vehicle collision test as much as possible.

Background Art

[0002] Conventionally, in automobile manufacturers, a collision test is conducted in which a vehicle is actually collided to evaluate the strength of the vehicle body and the influence of the collision, assuming a vehicle collision accident. As an example of this type of vehicle collision test device, for example, the one shown in Patent Document 1 can be cited.

[0003] A configuration belonging to what is called a closed-loop method shown in the same document is shown in FIG. 7.

[0004] This vehicle collision test device includes a towing rope 101, a drum 102 that pulls the towing rope 101, a plurality of sheaves 103 engaged with the towing rope 101, a motor 104 that drives the drum 102, motor speed detection means 104a that detects the speed of the motor 104, a conversion unit 105a that converts the detected motor speed into an actual towing speed and feeds it back, and control means 105 that inputs a torque command Tr to the motor 104 through a PI control unit 152 based on the deviation from a towing speed command Vref.

[0005] Then, the vehicle 107 is connected to the towing rope 101 via a connection / disconnection switching means 106, the vehicle 107 is driven on a traveling road 108, and then the vehicle 107 is disconnected by the connection / disconnection switching means 106 and collided with an object 109 at a predetermined speed to conduct a test.

[0006] FIG. 8 shows an acceleration diagram and a vehicle speed diagram that are the execution criteria for a towing speed command Vref in the control means 105. The acceleration is set to be completed within a basic acceleration time A.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 7-35651 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0008] Incidentally, since the vehicle 107 must be accelerated to a predetermined high speed within a limited length of the travel path 108, the acceleration is large, and the towing rope 101, having a spring constant, is stretched considerably during acceleration, and then contracts before the end of acceleration.

[0009] This stretching and contracting of the tow rope 101 causes a discrepancy between the speed of the vehicle 107 and the speed of the motor 104. As a result, in response to the towing speed command in Figure 9, the actual vehicle speed oscillates with overshoot and undershoot after acceleration is complete, as shown in Figure 10, causing the vehicle speed (actual towing speed) to deviate from the predetermined speed (target towing speed) at the vehicle 107's detachment position P. This problem becomes more pronounced the longer the tow rope is.

[0010] This invention has been made in view of these problems, and aims to solve them by changing the traction speed of the traction motor in accordance with the load on the traction motor near the completion of acceleration, when transitioning from acceleration, which has a large impact on the traction speed, to traction at a constant speed. [Means for solving the problem]

[0011] To achieve this objective, the present invention employs the following means.

[0012] In other words, the vehicle crash test apparatus according to the present invention comprises a towing rope, a drum for towing the towing rope, a motor for driving the drum, a motor speed detection means for detecting the speed of the motor, and the detected motor speed Traction speed commandThe system includes a control means that returns to the motor and inputs a torque command, and the vehicle is connected to the towing rope via a connection / disconnection switching means to perform a collision test, wherein the control means, at a predetermined timing near the completion of acceleration, The traction speed correction amount is calculated from the torque command, and based on this traction speed correction amount, This method is characterized by correcting the traction speed command of the motor in a direction that reduces the load.

[0013] The area near the completion of acceleration refers to the region where the vehicle transitions from acceleration to traction at a constant speed. In this manner, the control means can apply a correction to the traction speed command according to the load amount near the completion of acceleration. This suppresses vibrations caused by the vehicle speed overshooting due to the contraction of the traction rope when transitioning from acceleration to a constant speed, and subsequent overshoot and undershoot due to the expansion and contraction of the rope. As a result, the amount by which the vehicle speed deviates from the predetermined speed can be suppressed.

[0015] In this way, the amount of stretch in the tow rope can be detected from the torque command, and by performing speed correction in real time according to the amount of stretch, vibration of the tow rope after acceleration is complete can be suppressed. Moreover, with this control, there is no need to pre-set conditions such as the vehicle weight or test distance. [Effects of the Invention]

[0022] As described above, the present invention makes it possible to provide a vehicle crash test device that can not only suppress the amount by which the vehicle speed deviates from a predetermined speed, but also suppress vibrations caused by this speed deviation (when the actual towing speed of the vehicle deviates above or below the target towing speed), and stabilize the posture of the vehicle and the dummy mannequin installed inside the vehicle. [Brief explanation of the drawing]

[0023] [Figure 1] A schematic diagram illustrating the configuration of a vehicle crash test apparatus according to the first embodiment of the present invention. [Figure 2] A diagram showing the towing speed command. [Figure 3]A diagram showing the actual vehicle speed with respect to the traction speed command. [Figure 4] A diagram showing a modified example of the first embodiment. [Figure 5] A schematic configuration explanatory diagram of a vehicle collision test device according to the second embodiment of the present invention. [Figure 6] A diagram showing a modified example of the second embodiment. [Figure 7] A schematic configuration explanatory diagram of a conventional vehicle collision test device. <上 [Figure 8] A vehicle speed diagram and an acceleration diagram serving as execution criteria for the traction speed command. [Figure 9] A diagram showing the traction speed command. [Figure 10] A diagram showing the actual vehicle speed with respect to the traction speed command.

Mode for Carrying Out the Invention

[0024] (First Embodiment) Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.

[0025] The basic configuration of the vehicle collision test device shown in FIG. 1 is the same as that described above based on FIG. 7, and includes a traction rope 1, a drum 2 that pulls the traction rope 1, a plurality of sheaves 3 engaged with the traction rope 1, a motor 4 that drives the drum 2, a motor speed detection means 4a that detects the speed of the motor 4, and a conversion unit 5a that converts the detected motor speed into the actual traction speed and feeds it back, and based on the deviation from the traction speed command Vref, a control means 5 that inputs a torque command Tr to the motor 4 through a PI control unit 52.

[0026] Then, the vehicle 7 is connected to the traction rope 1 via a disconnection / connection switching means 6, the vehicle 7 is run on the travel road 8, and then the vehicle 7 is disconnected by the disconnection / connection switching means 6 and collided with the object 9 at a predetermined speed to conduct a test.

[0027] The tow rope 1 is endless in shape, and in this embodiment, it is wound around a drum 2 located at one end and a return sheave 3A located at the other end. An intermediate sheave 3B located in the middle engages with the tow rope 1 at two points and rotates synchronously, circulating endlessly through winding and unwinding by the drum 2.

[0028] Motor 4 uses either a variable-speed motor (such as a DC motor or inverter motor) or a constant-speed motor equipped with an acceleration / deceleration device to enable towing at various speeds and accelerations. Motor 4 is provided with a motor speed detection unit 4a.

[0029] The control means 5 retrieves the traction speed command Vref from the storage unit 5b and uses it as an input signal. The motor speed detected by the motor speed detection unit 4a is converted to the actual traction speed by the conversion unit 5a and fed back to the addition / subtraction unit 51. Based on the deviation from the traction speed command Vref, a torque command Tr is input to the motor 4 via the PI control unit 52.

[0030] Vehicle 1 can be an actual vehicle or a dummy vehicle. A dolly 6 is positioned at connection point C as a means of switching between connected and disconnected, and vehicle 7 is connected to the dolly 6 via a connecting wire 6a. Vehicle 7 travels along the track 8, is disconnected when the dolly 6 releases the connection of the connecting wire 6a, and then collides with an object 9. The object 9 is an obstacle or another vehicle.

[0031] The control means 5 stores data related to the speed diagram and vehicle speed diagram shown in Figure 8 in the storage unit 5b, and generates a traction speed command Vref based on this data.

[0032] In accordance with the speed diagram and vehicle speed diagram in Figure 8, various conditions are set and stored in memory 5b so that the vehicle 7 can be accelerated to a predetermined high speed within a limited length of track 8. These conditions involve raising the acceleration to a predetermined value at the beginning of acceleration, maintaining a constant acceleration in the middle of acceleration, and then accelerating at the end of acceleration so that the speed does not drop until just before the vehicle uncoupling point, thereby completing the acceleration within the basic acceleration time A. At that time, in order to stabilize the behavior of the vehicle 7 during towing, a rounded control region is provided at the beginning and end of acceleration to avoid sudden acceleration and deceleration.

[0033] Specifically, the acceleration is increased to a predetermined value in the initial acceleration range t1, then constant acceleration is maintained in the middle constant acceleration range t2, and finally acceleration is maintained in the final acceleration range t3 so that the speed does not decrease until just before the vehicle separation position P. Overall, acceleration control is performed along an S-shaped acceleration line as shown in Figures 8 and 9.

[0034] In this configuration, as mentioned above, the vehicle 7 must be accelerated to a predetermined high speed within a limited length of the travel path 8, so the acceleration is large, and the towing rope 1, having a spring constant, is stretched considerably during acceleration. When the speed of the vehicle 7 approaches the predetermined target speed and the acceleration is reduced to match that speed correctly, the driving force of the motor 4 decreases, causing the rope to contract from its stretched state. Furthermore, if it contracts too much, it will then return to its original state and try to stretch again.

[0035] Therefore, even when the tow rope 1 is being towed at a predetermined towing speed at the position of the drum 2 shown in Figure 1, the stretching and contracting of the tow rope 1 causes a discrepancy between the speed of the vehicle 7 connected to the tow rope 1 at the position of the dolly 6 and the speed of the motor 4 (actual towing speed at the position of the drum 2). As a result, in response to the towing speed command shown in Figure 9, the actual vehicle speed (measured value) oscillates with overshoot and undershoot after acceleration is complete, as shown in Figure 10, and the vehicle speed deviates from the predetermined speed at the uncoupling position P of the vehicle 7.

[0036] Of these, the acceleration region t3 at the end has a particularly large impact on the traction speed, that is, the Z region near the completion of acceleration, where the traction transitions from acceleration to constant speed as shown in Figure 2. Therefore, in this embodiment, control is performed to correct the traction speed of motor 4 in the direction of reducing the load on motor 4 in accordance with the load on motor 4 at this Z region near the completion of acceleration.

[0037] Specifically, when the control means 5 determines that the final stage of acceleration has arrived based on the pre-set acceleration diagram in Figure 8 (i.e., when it determines that the acceleration near completion point Z has arrived in the traction speed command diagram in Figure 2), in addition to the feedback control that has been performed up to that point, which feeds the motor speed back to the traction speed command Vref, it inputs the torque command Tr to the speed correction amount calculation unit 53 to calculate the traction speed correction amount ΔV, and performs control to correct the traction speed command Vref based on this traction speed correction amount ΔV. One example is to set ΔV = k·Tr (where k is a proportionality constant).

[0038] The torque command Tr is equal to the motor load, and the motor load is equal to the tension T of the traction rope 1. Therefore, the larger the torque command Tr, the more the traction rope 1 is stretched, and the greater the amount of contraction when the tension T is released after acceleration is complete. To address this, the traction speed correction amount ΔV corresponding to the torque command Tr is subtracted from the traction speed command Vref, thereby reducing the tension T, i.e., the amount of stretch ΔL of the traction rope 1.

[0039] As described above, the vehicle crash test apparatus of this embodiment comprises a towing rope 1, a drum 2 that tows the towing rope 1, a motor 4 that drives the drum 2, and a control means 5 that inputs a torque command Tr to the motor 4 based on a towing speed command Vref. The crash test is performed by connecting a vehicle 7 to the towing rope 1 via a dolly 6 which is a connection / disconnection switching means. The control means 5 corrects the towing speed command Vref of the motor 4 in a direction that reduces the load amount, according to the load amount of the motor 4, at a predetermined timing Z near the completion of acceleration.

[0040] Overshoot occurs when the tow rope 1 contracts after acceleration is complete. In this way, the control means 5 can apply a load-dependent correction to the tow speed command Vref near the end of acceleration Z, when transitioning from acceleration to constant speed towing. This suppresses vibrations that cause the vehicle speed to overshoot due to the contraction of the tow rope 1 when transitioning from acceleration to constant speed, and then overshoot and undershoot due to the subsequent expansion and contraction. As a result, the amount by which the vehicle speed deviates from a predetermined speed can be suppressed.

[0041] Furthermore, vibrations caused by this speed deviation (where the actual towing speed of vehicle 7 deviates above or below the target towing speed) are suppressed, stabilizing the attitude of vehicle 7. This also helps to suppress fluctuations in the lateral and longitudinal pitch behavior of vehicle 1 near the completion of acceleration Z, as well as positional displacement of the measurement dummy mounted on vehicle 7, thereby improving the accuracy of the data collected in the crash test.

[0042] Specifically, the traction speed correction amount ΔV is calculated from the torque command Tr, and the traction speed command Vref is corrected based on this traction speed correction amount ΔV.

[0043] In this way, the amount of elongation in the tow rope 1 can be detected from the torque command Tr, and by performing a speed correction in real time according to the amount of elongation ΔL near the completion of acceleration Z, vibration of the tow rope 1 after the completion of acceleration can be suppressed in advance. Moreover, with this control, there is no need to pre-set conditions such as the weight of the vehicle or the test distance.

[0044] (modified version) Next, we will explain Figure 4, which is a modified example of Figure 1.

[0045] This modified version is basically the same as the first embodiment in Figure 1, and comprises a towing rope 1, a drum 2 that tows the towing rope 1, a motor 4 that drives the drum 2, and a control means 5 that inputs a torque command to the motor 4 based on a towing speed command Vref. A vehicle 7 is connected to the towing rope 1 via a dolly 6, which is a connection / disconnection switching means, and a crash test is performed.

[0046] Furthermore, as a method by which the control means 5 corrects the traction speed command Vref of the motor 4 in the direction of reducing the load amount in accordance with the load amount of the motor 4 at a predetermined timing near the completion of acceleration Z, instead of detecting how much the traction rope is stretched from the torque command Tr, the traction speed command is made using a preset value Vref' of the traction speed command Vref for each traction condition stored in the memory unit 5b.

[0047] If the towing conditions, such as the weight of the vehicle 7 and the distance to be towed, are determined quantitatively from the beginning, it is possible to determine how much acceleration is needed to shorten the towing rope 1 and what speed the vehicle will reach near the end of acceleration Z. Therefore, the towing speed command Vref in Figure 2 is modified to take into account the process of the towing rope 1 shortening near the end of acceleration (the actual towing speed of the vehicle will be higher than the target towing speed), and this modified value Vref' is stored in the memory unit 5b in the form of a speed command diagram or appropriate map as shown in Figure 2. The control means 5 controls the motor 4 based on this preset value Vref' and the actual towing speed converted from the motor speed and fed back to the system.

[0048] In this way, the traction speed command Vref' itself takes into account the contraction of the traction rope 1 near the completion of acceleration Z and performs acceleration accordingly. Therefore, overshoot and undershoot after the completion of acceleration can be suppressed without configuring a feedback system using the torque command Tr.

[0049] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figure 5.

[0050] This embodiment is basically the same as the first embodiment in Figure 1, and comprises a towing rope 1, a drum 2 that tows the towing rope 1, a motor 4 that drives the drum 2, and a control means 5 that inputs a torque command to the motor 4 based on a towing speed command Vref. A vehicle 7 is connected to the towing rope 1 via a dolly 6, which is a connection / disconnection switching means, and a collision test is performed.

[0051] Then, at a predetermined timing near the completion of acceleration Z, the control means 5 corrects the traction speed command Vref of the motor 4 in a way that reduces the load amount according to the load amount of the motor 4. Here too, the torque command Tr is input to the speed correction amount calculation unit 53 to calculate the traction speed correction amount ΔV, and the traction speed command Vref is corrected based on this traction speed correction amount ΔV.

[0052] However, simply feeding back the torque command Tr does not involve the concept of integration on the time axis, which can easily lead to abrupt or gradual speed correction. Therefore, the transition time calculation unit 54 uses the towing condition setting values ​​pre-stored in the memory unit 5b, including the weight of the vehicle 7, the distance traveled, and the towing command diagram in Figure 2, to calculate the transition time Δt (see Figure 2) near the completion of acceleration Z, i.e., the transition time from acceleration to a constant speed. The speed correction amount calculation unit 53 then calculates the towing speed correction amount V' based on these torque command Tr and the transition time Δt, and corrects the towing speed command Vref. One example is dV' / dt = k·Tr / Δt (where k is a coefficient).

[0053] This means that, for example, if there is ample time in the transition period Δt, the rounding control will be adjusted accordingly, and if the transition period Δt is short, the velocity correction will be completed quickly within that transition period Δt.

[0054] In this way, the control means 5 can apply a correction to the traction speed command Vref at the point Z where acceleration is completed and the transition time Δt for the transition from acceleration to traction at a constant speed, and according to the load on the motor 4. As a result, the control means 5 operates to appropriately suppress vibrations that cause the vehicle speed to overshoot due to the contraction of the traction rope 1 when transitioning from acceleration to a constant speed, and then overshoot and undershoot due to subsequent expansion and contraction, according to the transition time Δt. Consequently, the amount by which the vehicle speed deviates from a predetermined speed can be suppressed.

[0055] (modified version) Next, we will explain Figure 6, which is a modified example of Figure 5.

[0056] This embodiment is basically the same as the second embodiment in Figure 5, and comprises a towing rope 1, a drum 2 that tows the towing rope 1, a motor 4 that drives the drum 2, and a control means 5 that inputs a torque command to the motor 4 based on a towing speed command Vref. A vehicle 7 is connected to the towing rope 1 via a dolly 6, which is a connection / disconnection switching means, and a collision test is performed.

[0057] Furthermore, as a method for correcting the traction speed command Vref of the motor 4 in the direction of reducing the load amount in accordance with the load amount of the motor 4, the control means 5 detects how much elongation there is in the traction rope from the torque command Tr, calculates the transition time Δt in the transition time calculation unit 54, and calculates the traction speed correction amount V' based on this torque command Tr and transition time Δt to correct the traction speed command Vref, but rather makes a traction speed command using a preset value Vref'' of the traction speed command Vref for each traction condition stored in the storage unit 5b.

[0058] If the towing conditions, such as the weight of the vehicle 7 and the distance to be towed, are determined quantitatively from the beginning, it is possible to determine how much acceleration is needed to shorten the towing rope 1 and what speed the vehicle will reach near the end of acceleration Z. Therefore, taking into account the transition time Δt, the towing speed command in Figure 2 is modified to account for the process of the towing rope 1 shortening near the end of acceleration Z (the actual towing speed of the vehicle is higher than the towing speed command), and this modified value Vref'' is stored in the memory unit 5b as a preset value Vref'' in the form of a towing speed command diagram or appropriate map as shown in Figure 2. The control means 5 uses this preset value Vref'' to issue the towing speed command.

[0059] In this way, the pre-set value Vref'' of the traction speed command itself appropriately takes into account the contraction of the traction rope 1 within the transition time Δt when Z is near the completion of acceleration, and performs acceleration accordingly. Therefore, overshoot and undershoot after the completion of acceleration can be suppressed more effectively without configuring a feedback system using the torque command Tr.

[0060] Although embodiments of the present invention have been described above, the specific configuration of each part is not limited to the embodiments described above.

[0061] For example, in the above embodiment, the towing rope 1 was stretched between one drum 2 and a plurality of sheaves 3 (3A, 3B). However, the towing rope could also be wound between a pair of winding / unwinding drums and a return sheave, with the vehicle being towed and unwound via a dolly by driving one drum, and the dolly being returned to its original position by driving the other drum. A motor could be connected to the drums and controlled by a control means.

[0062] Furthermore, although the towing rope in the above embodiment is stretched in an oval shape, the form of tensioning and the number of sheaves are not limited, and depending on the layout, it may be stretched in a bent state with intermediate sheaves placed along the way.

[0063] Furthermore, although the control means in the above embodiment employs PI control, it may also be P control or PID control.

[0064] Furthermore, although the towing rope was stretched in an endless manner in the above embodiment, it may also be in an end-shaped manner.

[0065] Other configurations can also be modified in various ways without departing from the spirit of the present invention. [Explanation of Symbols]

[0066] 1... Towing rope 2… Drums 4…motor 5…Control means 6…Disconnection / Switching Mechanism (Dolly) 7…Vehicles Tr... Torque command Tref'...Pre-set value Tref´´…Pre-set value Vref…Traction speed command ΔV…Traction speed correction amount V´…Traction speed correction amount

Claims

[Claim 1] A collision test is performed by connecting a vehicle to the tow rope via a connection / disconnection switching means, comprising a tow rope, a drum for pulling the tow rope, a motor for driving the drum, a motor speed detection means for detecting the speed of the motor, and a control means for feeding back the detected motor speed to the tow speed command and inputting a torque command to the motor, The vehicle collision test apparatus is characterized in that the control means calculates a traction speed correction amount from the torque command at a predetermined timing near the completion of acceleration, and corrects the traction speed command of the motor in a direction that reduces the load amount based on this traction speed correction amount.

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