Suspension system simulation method in 3-axis motor drive bench

Abstract

To provide a suspension system simulation method in a 3-axis motor drive bench that can reproduce influence of the suspension system.SOLUTION: A suspension system simulation model 5 on a bench, which is a model that reproduces an effect of power plant vibration on a torsional vibration system of a drive train, is combined with bench rotation control to reproduce calculation results of the suspension system simulation model 5. The suspension system simulation model 5 is a mathematical expression of an effect of a roll direction component of vibration of a power plant suspended in a suspension system on the torsional vibration system of a drive train. In the bench rotation control, additional torque and an additional rotation angle calculated by the suspension system simulation model 5 are commanded to a drive shaft dynamometer M1 and absorption shaft dynamometers M2 and M3 of the bench, and the absorption shaft dynamometers M2 and M3 are controlled to follow the rotation in response to the command while countering transmitted torque.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for simulating a suspension system in a three-axis motor-driven bench.

Background Art

[0002] Conventionally, when evaluating noise and vibration (NV evaluation) in a power plant mounted on a vehicle such as a hybrid vehicle, a technique of evaluating a vehicle (front-loading vehicle evaluation) without using an actual vehicle (completed vehicle) by using a three-axis motor-driven bench is known.

[0003] Patent Document 1 discloses a logic for calculating the torque required for vibration suppression in consideration of the vibration of a power plant suspended by a suspension system based on an engine torque pulsation map and a motion equation acquired in advance in order to suppress the vibration at the start of the engine in a vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a three-axis motor-driven bench, due to the restraint conditions of the bench, the transmission is fixed to the panel surface. Therefore, simply applying the logic described in Patent Document 1 as it is cannot simulate on the bench the influence of the suspension system (vibration of the power plant) on the torsional vibration system of the drive train. That is, the influence of the suspension system cannot be reproduced on the bench.

[0006] In order to reproduce the influence of the suspension system on a three-axis motor-driven bench, the inventors of the present invention have obtained new findings that it is necessary to formulate the influence of the vibration of the power plant on the inside of the transmission and reproduce it on the bench.

[0007] The present invention has been made in view of such points, and an object thereof is to provide a suspension system simulation method in a three-axis motor-driven bench capable of reproducing the influence of the suspension system.

Means for Solving the Problems

[0008] The solution means of the present invention for achieving the above object is directed to a suspension system simulation method in a three-axis motor-driven bench. And this suspension system simulation method in a three-axis motor-driven bench combines a suspension system simulation model on the bench, which is a model for reproducing the influence of the vibration of the power plant on the torsional vibration system of the drive train, and bench rotational speed control for reproducing the calculation result of the suspension system simulation model. It generates the suspension system simulation model that formulates the influence of the component in the roll direction of the vibration of the power plant suspended by the suspension system on the torsional vibration system of the drive train, and issues commands to add the additional torque and additional rotation angle calculated by the suspension system simulation model to the drive shaft power meter and absorption shaft power meter of the bench respectively. In response to each command, the absorption shaft power meter performs control to follow the rotational speed while counteracting the torque transmitted through the drive shaft power meter and the power transmission system.

[0009] As the concept of the additional command of the "additional rotation angle" mentioned here, those that substitute the additional rotation angle with the rotational speed (rotational number) and issue an additional command are also included.

[0010] Due to this specific matter, it becomes possible to reproduce the influence of the suspension system (vibration of the power plant) on the torsional vibration system of the drive train on a three-axis motor-driven bench.

Effects of the Invention

[0011] In the present invention, as a suspension system simulation method in a three-axis motor-driven bench, a suspension system simulation model on a bench, which is a model for reproducing the influence of the vibration of a power plant on the torsional vibration system of a drive train, and bench rotational speed control for reproducing the calculation result of the suspension system simulation model are combined, so that it is possible to reproduce the influence of the suspension system (the vibration of the power plant) on the torsional vibration system of the drive train. As a result, the front load of vehicle evaluation can be carried out with high accuracy.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a case where the present invention is applied to a three-axis motor-driven bench assuming an internal combustion engine (engine) as a driving power source of a vehicle will be described.

[0014] -Schematic Configuration of Three-Axis Motor-Driven Bench- FIG. 1 is a conceptual diagram of a three-axis motor-driven bench 1 according to this embodiment. As shown in this FIG. 1, the three-axis motor-driven bench 1 includes a drive shaft dynamometer M1, a first absorption shaft dynamometer M2, and a second absorption shaft dynamometer M3 connected to a transmission 2.

[0015] The transmission 2 has its housing fixed to a face plate (not shown). That is, in an actual vehicle, the transmission is elastically supported by a suspension system (mount) on the vehicle body, whereas in the three-axis motor-driven bench 1, the transmission 2 is fixed to the face plate.

[0016] As described above, in the prior art, due to this configuration, the influence of the suspension system (vibration of the power plant) on the torsional vibration system of the drive train could not be simulated on the bench.

[0017] In the present embodiment, as will be described later, the influence of the vibration of the power plant on the inside of the transmission (the influence of the rolling direction component of the vibration of the power plant on the torsional vibration system of the drive train) is formulated, and by reproducing it on the bench, the influence of the suspension system can be reproduced on the three-axis motor-driven bench 1. This will be specifically described below.

[0018] The drive shaft dynamometer M1 is connected to the transmission 2 (for example, the input shaft) via the drive shaft 31. A drive shaft torque meter 41 is provided on this drive shaft 31. The drive shaft dynamometer M1 simulates the engine which is the drive power source of the vehicle.

[0019] Also, the first absorption shaft dynamometer M2 is connected to the transmission 2 (for example, the output shaft) via one side drive shaft (absorption shaft) 32. A first torque meter 42 is provided on this drive shaft 32. This first absorption shaft dynamometer M2 simulates one drive wheel.

[0020] Furthermore, the second absorption shaft dynamometer M3 is connected to the transmission 2 (for example, the output shaft) via the other side drive shaft (absorption shaft) 33. A second torque meter 43 is provided on this drive shaft 33. This second absorption shaft dynamometer M3 simulates the other drive wheel.

[0021] Furthermore, the dashed arrows in FIG. 1 represent signals input to or output from each torque meter 41, 42, 43, each power meter M1, M2, M3, and the suspension system simulation model 5 described below.

[0022] -Overview of Suspension System Simulation- As described above, in this embodiment, the influence of the vibration of the power plant on the inside of the transmission is formulated, and by reproducing it on the bench, the influence of the suspension system is reproduced on the three-axis motor-driven bench 1.

[0023] As specific means for that, the following two are combined.

[0024] (1) Construction of a model for simulating the suspension system (reproducing the influence of the vibration of the power plant on the torsional vibration system of the drive train) on the three-axis motor-driven bench 1 (2) Rotational speed control on the three-axis motor-driven bench 1 necessary for reproducing the calculation results of the suspension system simulation model Hereinafter, these means will be described.

[0025] First, the suspension system simulation model will be described. The three-axis motor-driven bench 1 according to this embodiment includes a suspension system simulation model 5 that receives information from each torque meter 41, 42, 43. This suspension system simulation model 5 is a model for reproducing the influence of the vibration of the power plant on the torsional vibration system of the drive train. In this embodiment, in order to reproduce this influence, the suspension system simulation model 5 calculates an additional torque to be added to the torque command value (control command value) given to the drive shaft power meter M1, and an additional rotation angle (specifically, a substituted additional rotational speed) to be added to the rotational speed command value (control command value) given to each absorption shaft power meter M2, M3. Then, the additional torque is added to the drive shaft power meter M1, and the additional rotation angle (additional rotational speed) is added to each absorption shaft power meter M2, M3. Hereinafter, it will be specifically described.

[0026] The suspension system simulation model 5 is a model that formulates, based on the balance with the equations of motion, the influence exerted by the vibration of a power plant (such as an engine and a transmission 2, etc.) suspended by a suspension system (mount) on the torsional vibration system of a drive train (a driving force transmission system extending from the engine → transmission 2 → drive shafts 32, 33).

[0027] Then, in order to reproduce the influence of the suspension system on the three-axis motor-driven bench 1, from this mathematical formula, coordinate transformation is performed with the rotation angle (rotation angle) of the shaft inside the transmission 2 as the axis. As a result, the input value to the suspension system simulation model 5 on the three-axis motor-driven bench 1, the additional torque necessary for the suspension system simulation in the drive shaft dynamometer M1, and the additional rotation angle necessary for the suspension system simulation in each absorption shaft dynamometer M2, M3 are calculated.

[0028] Hereinafter, the processing performed in this suspension system simulation model 5 will be described.

[0029] First, coordinate transformation is performed with the rotation angle inside the transmission 2 as the axis.

[0030] FIG. 2 is a conceptual diagram showing an example of the gear configuration of the transmission of the three-axis motor-driven bench 1 according to the present embodiment. In this FIG. 2, the gear G1 is a gear connected to the drive shaft 31 (connected to the drive shaft dynamometer M1), the gear G3 is a gear connected to the drive shaft 32 (33) (connected to the absorption shaft dynamometer M2 (M3)), and the gear G2 is a gear (such as a counter gear) that meshes with each of the gears G1 and G3 and transmits power. And in this FIG. 2, I is the moment of inertia, θ is the rotation angle, r is the radius of rotation, T is the torque, F is the driving force, K is the spring constant in the suspension system simulation model, C is the damping coefficient, and the subscripts 1 to 3 of each correspond to the numbers of the respective gears G1, G2, G3, the subscript d represents the drive shafts 32, 33, the subscript p represents the power plant, and b represents the tire (driving wheel). Note that the K in this FIG. 2 d C dIt simulates the grounding state of the vehicle tires. This value is for obtaining appropriate torque reaction forces such that each of the dynamometers M1, M2, and M3 is not shaken.

[0031] The engine inertia formula, gear constraint condition, torsion formulas of the drive shafts 32 and 33, and torsion formula of the power plant in the absolute coordinate system obtained from the configuration shown in this Figure 2 are shown below.

[0032]

Number

[0033]

Number

[0034]

Number

[0035] Specifically, it will be described with reference to FIG. 3 (a conceptual diagram for explaining the principle of suspension system simulation on the three-axis motor-driven bench 1 according to the present embodiment). In FIG. 3, only the first absorption axis dynamometer M2 is shown as the absorption axis dynamometer in order to simplify the drawing, but the same processing is performed for the second absorption axis dynamometer M3. In FIG. 3, each signal input to the suspension system simulation model 5, the torque (command value) input to the drive axis dynamometer M1, and the rotational speed (command value) input to the absorption axis dynamometer M2 (M3) are indicated by dashed arrows, and the signals output from the suspension system simulation model 5 (the additional torque and additional rotation angle described above) are indicated by solid arrows.

[0036] As shown in FIG. 3, T in the torsion formula of the drive shaft 32 (33) in the relative coordinate system p is input to the suspension system simulation model 5. That is, the torque F·r1 obtained by the drive shaft torque meter 41, the torque F·r3 obtained by the first torque meter 42, and the torque command value T given to the drive axis dynamometer M1 are input to the suspension system simulation model 5.

[0037] Then, the third term on the right side of the engine inertia formula (the converted engine inertia formula) in the relative coordinate system calculated by this suspension system simulation model 5 is calculated as the additional torque, and θ on the right side of the torsion formula (the formula of F·r3) of the drive shaft 32 (33) p is calculated as the additional rotation angle.

[0038] And, as described above, for the rotational speed control on the three-axis motor-driven bench 1 necessary to reproduce the calculation result of the suspension system simulation model 5, the third term on the right side of the engine inertia formula in the relative coordinate system calculated by the suspension system simulation model 5 is input to the drive axis dynamometer M1 as the additional torque. Also, θ on the right side of the torsion formula (the formula of F·r3) of the drive shaft 32 (33) pIt is input to the absorption shaft dynamometer M2 (M3) as an additional rotation angle. At this time, since it is difficult to control the rotation angle on the three-axis motor-driven bench 1, in this embodiment, on the condition that the deviation between the target rotation speed and the measured rotation speed is equal to or less than a predetermined value, the control of this rotation angle is substituted by the control of the rotation speed (rotation number) and input to the absorption shaft dynamometer M2 (M3). This is based on the fact that suspension system simulation can be realized by using rotation speed control instead of rotation angle control if the rotation tracking performance (gain) between the target rotation speed and the actual rotation speed is within, for example, ±1 dB between, for example, 20 to 45 Hz under the influence of the suspension system.

[0039] The additional torque is calculated by multiplying the angular acceleration in the roll direction of the vibration of the power plant by the inertia around the crankshaft of the engine and the inertia of the flywheel damper. Further, the additional rotation angle (additional rotation speed) is calculated by integrating the angular acceleration in the roll direction of the power plant.

[0040] In this way, when the additional torque is input to the drive shaft dynamometer M1 and the additional rotation speed is input to the absorption shaft dynamometer M2 (M3), in the case of the absorption shaft dynamometer M2 (M3), while counteracting the torque transmitted from the engine (drive shaft dynamometer M1) → transmission 2 / transaxle → drive shaft 32 (33), control capable of following the rotation speed is required. That is, the rotation speed of the absorption shaft dynamometer M2 (M3) is controlled while counteracting by the reaction torque. In other words, the absorption shaft dynamometer M2 (M3) counteracts while generating a reaction torque against the torque input from the drive shafts 32 and 33 as much as possible, and in that state, it is controlled so as to be able to reproduce the target rotation speed required for suspension system simulation. In this case, if the torque and rotation fluctuation are commanded from the suspension system simulation model 5 to be equal to or higher than the rotation speed measurement and control accuracy of the absorption shaft dynamometer M2 (M3), it is possible to realize suspension system simulation on the three-axis motor-driven bench 1.

[0041] As described above, in the present embodiment, as a suspension system simulation method in the three-axis motor-driven bench 1, a suspension system simulation model 5 on the bench, which is a model for reproducing the influence of the vibration of the power plant on the torsional vibration system of the drive train, and bench rotational speed control for reproducing the calculation result of the suspension system simulation model 5 are combined. As a result, the influence of the vibration of the power plant suspended by the suspension system (mount) on the torsional vibration system of the drive train can be reproduced, and an accurate difference will appear in the torque transmission characteristics from the engine (drive shaft power meter M1) to the drive shafts 32 and 33 (absorbing shaft power meters M2 and M3). Therefore, it is possible to reproduce the influence of the suspension system (vibration of the power plant) on the torsional vibration system of the drive train. As a result, the front load of vehicle evaluation can be carried out with high accuracy.

[0042] -Other Embodiments- Note that the present invention is not limited to the above-described embodiment, and all modifications and applications included in the scope of the claims and the scope equivalent thereto are possible.

[0043] For example, in the above-described embodiment, the case where the present invention is applied to the three-axis motor-driven bench 1 that simulates an internal combustion engine as a driving force source of a vehicle has been described. The driving force source of the vehicle to be simulated is not limited to an internal combustion engine, and it is also possible to simulate other driving force sources.

[0044] In addition, as a countermeasure when there is a parallel-axis gear reaction force that cannot be measured in the driving force transmission system of a vehicle, among the torques applied to the suspension system, regarding the parallel-axis gear reaction force, when it cannot be directly measured, it is possible to substitute for other transmissions or transaxles by estimating from the measurable part of the torque and the gear ratio.

Industrial Applicability

[0045] The present invention is applicable to a suspension system simulation method in a three-axis motor-driven bench.

Explanation of Reference Numerals

[0046] 1 3-axis motor-driven bench 2 Transmission 31 Drive shaft 32, 33 Drive shaft 5 Suspension system simulation model M1 Drive shaft power meter M2 First absorption shaft power meter M3 Second absorption shaft power meter

Claims

【Claim 1】 A suspension system simulation method for a three-axis motor-driven bench, which combines a suspension system simulation model on a bench, which is a model for reproducing the influence of the vibration of a power plant on the torsional vibration system of a drive train, and bench rotational speed control for reproducing the calculation results of the suspension system simulation model, generates the suspension system simulation model that formulates the influence of the roll-direction component of the vibration of the power plant suspended by the suspension system on the torsional vibration system of the drive train, issues a command to add the additional torque and additional rotation angle calculated by the suspension system simulation model to the drive shaft power meter and absorption shaft power meter of the bench, respectively, and, in response to each command, the absorption shaft power meter performs control to follow the rotational speed while counteracting the torque transmitted through the drive shaft power meter and the drive power transmission system. A suspension system simulation method for a three-axis motor-driven bench, characterized by this.

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