JP5292922B2 - Method and apparatus for estimating roller surface driving force - Google Patents

Description

  The present invention relates to a roller surface driving force estimation method and apparatus in a dynamometer system.

An electric inertia control system is employed to electrically compensate a mechanical inertia component of a power measurement target on the load side or drive side of the dynamometer measurement system. As this electric inertia control system, Patent Document 1 is known. In Patent Document 1, a shaft torque generated in a power transmission shaft of a vehicle is detected by an installed shaft torque meter. The dynamometer obtains the electric inertia torque set value from the detected value of the shaft torque, the torque set value for the running resistance excluding the mechanical inertia, and the mechanical inertia and the set inertia of the dynamometer. The absorption torque is controlled by the sum of the torque setting value for the running resistance. Further, it is described that the acceleration detection for electric inertia control is not required, thereby improving the response of electric inertia control and enabling stable control.
JP 2004-361255 A

  In Patent Document 1, a mechanical system model of a dynamometer is a two-inertia system having resonance characteristics. Since the resonance characteristic of the mechanical system is not considered in Patent Document 1, an unstable phenomenon such as hunting or divergence due to the resonance characteristic of the mechanical system occurs when an attempt is made to increase the electrical inertia control response. In addition, chassis dynamometer systems and drive train bench system dynamometer systems have shaft torque detection characteristics, dynamometer angular velocity detection characteristics, and inverter response characteristics in addition to mechanical resonance characteristics, and these are the detection delays in shaft torque. Without considering the torque response delay factor of the inverter or the inverter, stable control with higher response cannot be performed.

In order to perform stable control with higher response, high accuracy of the roller surface driving force estimation device is required. Further, even when a test vehicle does not have a measuring device for measuring driving force such as a wheel torque meter or a six-component force meter, highly accurate roller surface driving force measurement is required.
FIG. 6 shows a schematic configuration diagram of a chassis dynamometer system, where Dy is a dynamometer, R is a roller connected to the dynamometer Dy, IV is an inverter, and RP is a roller surface driving force estimation unit provided in the control unit. , TM is a shaft torque meter, EC1 is an encoder for detecting the rotational speed of the dynamometer, EC2 is an encoder for detecting the rotational speed of the roller, and each detection detected by the shaft torque meter TM and encoders EC1 and EC2 The signal is input to the roller surface driving force estimation unit RP.
FIG. 7 shows a configuration diagram of the roller surface driving force estimation unit RP. The primary low-pass filter is set to 1 / Td · s + 1, the time constant Td of the primary low-pass filter is set, and the angular velocity dt is set to the roller inertia Jroller. A low-pass filter is passed through the output multiplied by / dω, and the shaft torque detection is subtracted to calculate the estimated roller surface driving force.
However, since there are shaft torque detection delays and speed detection delays in the dynamometer, it is difficult to evaluate the roller surface driving force estimation value and perform highly responsive roller surface driving force estimation.

  Accordingly, an object of the present invention is to provide a roller surface driving force estimation method and apparatus capable of evaluating a roller surface driving force estimated value and providing a high response.

Claim 1 of the present invention is a chassis dynamometer system in which a dynamometer connected to a roller via a shaft is controlled by an inverter according to an output of a control unit, and the roller surface driving force is estimated by an observer unit included in the control unit. In what
An observer generalized plant model is created by a controller design method called the H∞ control and μ design method for the observer unit and a mechanical system model for estimating the roller surface driving force provided in the observer unit,
The generalized plant model of the observer unit is a mechanical system model that inputs a roller surface driving force signal and a dynamometer torque command that are respectively weighted, and calculates a roller angular velocity signal, a shaft torque signal, and a dynamometer angular velocity signal. A torque meter characteristic model that inputs a shaft torque signal from a mechanical system model and outputs a shaft torque detection signal, and an encoder characteristic model that inputs a roller angular speed signal calculated by the mechanical system model and outputs a roller angular speed signal And
The sum of the torque detection signal generated via the torque meter characteristic model and the weighted shaft torque detection error signal is input as an observation signal to the controller as an axis torque detection signal and detected via the encoder characteristic model The sum of the measured roller angular velocity signal and the weighted dynamometer angular velocity observation noise is input as an observation signal to the controller as a detection signal of the dynamometer angular velocity, and the output of the controller and the weighted roller surface driving force signal The difference signal is used as a weighted roller surface driving force estimation signal.

According to a second aspect of the present invention, the mechanical system model for estimating the roller surface driving force is a roller angular velocity signal which is a sum of a rotational moment torque of the roller and a shaft torsion torque signal due to the vehicle driving force applied to the roller surface. A roller moment of inertia element to be calculated; a dynamometer moment of inertia element that calculates the angular velocity signal of the dynamometer based on the difference between the input dynamometer torque signal and the shaft torsion torque signal; and the angular velocity signal of the dynamometer and the roller angular velocity signal It is characterized by having each transfer function of a spring stiffness element for calculating the shaft torsion torque signal by the difference.

According to a third aspect of the present invention, the dynamometer connected to the roller through the shaft is controlled by an inverter based on a control signal from a control unit having an observer unit for estimating the roller surface driving force and a vibration command generating unit. In the chassis dynamometer system,
The observer unit inputs the angular velocity signal detected by the chassis dynamometer system and the shaft torque signal of the shaft to calculate the estimated roller surface driving force, and the excitation command from the excitation command generation unit is a torque current command. superimposed on, when configured to determine the frequency characteristic and transfer function observer output from the specified superimposed torque current command both
The observer unit and the mechanical system model for estimating the roller surface driving force provided in the observer unit are an observer generalized plant model created by a controller design method called H∞ control and μ design method,
The generalized plant model of the observer section is a mechanical system model that inputs a weighted roller surface driving force signal and a dynamometer torque command and calculates a roller angular velocity signal, a shaft torque signal of a shaft, and a dynamometer angular velocity signal. A torque meter characteristic model that inputs a shaft torque signal from a system model and outputs a detection signal of a shaft torque, an encoder characteristic model that inputs a dynamometer angular speed from a mechanical system model and outputs a dynamometer angular speed signal,
The generalized plant model inputs the sum of the torque detection signal generated via the torque meter characteristic model and the weighted shaft torque detection error signal as an axis torque detection signal as an observation signal to the controller, and The sum of the dynamometer angular velocity signal detected via the encoder characteristic model and the weighted dynamometer angular velocity observation noise is input as an observation signal to the controller as a dynamometer angular velocity detection signal, and the output of the controller and the weighting The roller surface driving force signal and the difference signal thus formed are used as weighted roller surface driving force estimation signals .

As described above, according to the present invention, the observer unit for executing the roller surface driving force estimation is designed by using a controller design method called H∞ control and μ design method. This makes it possible to design an observer unit that takes into account various characteristics that affect the control response performance of the dynamometer system, such as mechanical system resonance characteristics, shaft torque detection characteristics, dynamometer angular speed detection characteristics, and roller angular speed detection characteristics. This makes it possible to estimate the roller surface driving force with high response in the dynamometer system.
Further, by incorporating this observer unit into the control unit of the dynamometer system, it is possible to obtain the frequency characteristics and transfer function of the roller surface driving force estimation from the torque current command of the dynamometer. Further, even when the test vehicle does not have a measuring device for measuring driving force such as a wheel torque meter or a six-component force meter, the roller surface driving force can be measured with high accuracy.

The present invention does not provide the electric inertia control circuit itself as in Patent Document 1, and the observer (roller surface driving force estimation) portion of the roller surface driving force estimation circuit is referred to as “H∞ control” and “μ design method”. It is created by a so-called controller design method, and parameters of the state equation are calculated to obtain an estimated value of the roller surface driving force.
“H∞ control”, “μ design method”, and “generalized plant” are explained in general textbooks of robust control in, for example, Liu Yasushi, “Linear Robust Control”, Corona, 2002, etc. ing.

  The present invention is used in the chassis dynamometer system shown in FIG. 6 using a generalized plant model designed by using the above method. Hereinafter, a description will be given based on examples.

Fig. 1 shows the observer of the roller surface driving force estimation circuit, and Fig. 2 shows the parameters of the state equation using the "H∞ control" or "μ design method" based on the generalized plant. Is to be calculated.
The generalized plant model of the observer for estimating the roller surface driving force shown in FIG. 1 includes a roller surface driving force w1, a dynamometer torque command w2, a shaft torque observation noise w3, and a dynamometer angular velocity observation noise w4 as disturbances. The observation quantities A and B are detected and input to the controller 10. The disturbance signal assumes that the chassis dynamometer system is actually driven, and noise generated in the control loop at that time is a disturbance signal, and here, there are four disturbance signals w1 to w4. The controller 10 sets the parameters of the state equation for estimating the roller surface driving force, and determines the parameters based on an algorithm so that the gain becomes small. In the generalized plant model, z1 to z4 are generated as control amounts.

  The input disturbances are weighted individually in weighting factor adding means 1 (Ow1 (s)) to 4 (Ow4 (s)) and 11 (Oz1 (s)) to 14 (Oz4 (s)), respectively. The desired characteristics can be obtained. That is, in the means 1, a certain constant is multiplied by the weight applied to the vehicle driving force, and it is outputted to the mechanical system model 20 (Omec (s)) as a rotational moment torque J1.T of the roller and also outputted to the subtracting means 7. . In the means 2, a constant is multiplied by the weight applied to the torque command of the dynamometer, and the output is output to the mechanical system model 20 as J2.T. In the means 3, the weight applied to the detection error of the shaft torque is set to a certain constant or a characteristic such that the gain is increased in a high range, and is output to the adding means 5. In the means 4, the weight applied to the dynamometer angular velocity detection error is set to a certain constant or a characteristic such that the gain is increased in a high range, and is output to the adding means 6.

  8 (Otm (s)) is a torque meter characteristic generating means (torque meter characteristic model) for detecting the shaft torque. The shaft torque K12.T of the coupled shaft from the mechanical model 20 is input and added as a predetermined torque meter characteristic. Output to means 5. The adding means 5 adds the weighted shaft torque detection error signal and the torque meter characteristic to generate a shaft torque detection value, which is input to the controller 10 as the observation amount A. Reference numeral 9 (Oenc (s)) denotes an encoder characteristic generation means (encoder characteristic model), which inputs the dynamometer angular velocity J2.w from the machine model 20 to generate a predetermined encoder characteristic and outputs it to the adder 6. The adding unit 6 adds the weighted dynamometer angular velocity detection error signal and the encoder characteristic to generate a dynamometer angular velocity detection value, and outputs it to the controller 10 as an observation amount B. The controller 10 performs a predetermined calculation based on the input signal. The calculated signal is output to the subtracting means 7, subtracted from the rotational moment torque J1.T of the roller, and output to the means 11.

  The means 11 (Oz1 (s)) is a means for weighting the deviation value of the roller surface driving force estimation, and the weighted roller surface driving force is set to an integral characteristic or a predetermined characteristic such that the gain becomes low in a high range. The estimated value z1 is output. Means 12 (Oz2 (s)) is means for applying a weight to the shaft torque, and is a constant to which the shaft torque K12.T from the mechanical system model 20 is input or a predetermined value that increases the gain in the high range. The characteristic is output as a shaft torque control command z2. The means 13 (Oz3 (s)) is a means for applying a weight to the dynamometer angular velocity J2.w from the mechanical system model 20, and is weighted with a predetermined characteristic or a predetermined characteristic that increases the gain in a high frequency range. Output as the dynamometer command z3. Means 14 (Oz4 (s)) is means for applying a weight to the detection of the roller angular velocity from the mechanical system model 20, and outputs it as a weighted roller angular velocity command z4 as a characteristic that increases the gain in a certain constant or high frequency range.

The observer mechanical system model 20 for estimating the roller surface driving force shown in FIG. 2 expresses the mechanical characteristics of the dynamometer as a transfer function, and is a model of a two-inertia mechanical system. The mechanical system model in this embodiment has J1.T and J2.T as inputs, and J1.w, K12.T, and J2.w as outputs.
In the figure, 21 is a roller inertia moment element, and its output is outputted to the generalized plant as a roller angular velocity J1.w and also outputted to the subtracting means 26. A spring stiffness element 22 receives the difference signal between the dynamometer angular velocity and the roller angular velocity calculated by the subtracting means 26 and outputs it as a shaft torsion torque K12.T signal to the generalized plant. Output to. In the adding means 24, the rotational moment J1.T of the roller due to the vehicle driving force applied to the roller surface and the shaft torsion torque K12.T are added and input to the roller inertia moment element 21. Further, the subtracting means 25 obtains a difference signal between the input dynamometer torque signal J2.T and the shaft torsion torque K12.T and outputs it to the dynamometer inertia moment element 23. The angular velocity J2.w is calculated and output to the generalized plant and also output to the subtracting means 26.

  FIG. 3 is an apparatus for estimating the roller surface driving force by applying the observer part designed as shown in FIG. 1 to the chassis dynamometer system shown in FIG. 6, and this observer part is an angular velocity detected by an encoder. The signal and the shaft torque signal detected by the shaft torque meter are input, a predetermined calculation is executed, and the roller surface driving force estimated value is output.

  According to this embodiment, the observer unit can estimate the roller surface driving force with high response in the dynamometer system by considering the resonance characteristic of the mechanical system, the shaft torque detection characteristic, the dynamometer angular velocity detection characteristic, and the like. It will be.

FIG. 4 shows an observer generalized plant model for estimating the roller surface driving force according to the second embodiment. The difference from the observer generalized plant model of FIG. The signal is the roller angular velocity J1.w output from the mechanical system model 20. Therefore, the encoder characteristic output by the encoder characteristic generation unit 9 is generated based on the angular velocity of the roller and output to the addition unit 6. In the means 4 to which the roller angular velocity observation noise w4 is inputted , the weight applied to the roller angular velocity detection error is set to a certain constant or a characteristic such that the gain is increased in a high range, and is output to the adding means 6. . In the adding means 6, this signal and the signal from the means 4 are added and input to the controller 10 as the observation amount B of the roller angular velocity control deviation. Others are the same as in the first embodiment.

  According to this embodiment, the observed quantity in the generalized plant is the axial torque detection (observed quantity A) and the roller angular velocity control deviation (observed quantity B). Thereby, the same effect as Example 1 is acquired.

FIG. 5 is a block diagram showing an observer evaluation apparatus. Reference numeral 30 denotes an actual chassis dynamometer in which a vehicle under test is placed on a roller, and its dynamometer is controlled by the output of the inverter IV. Reference numeral 40 denotes a control unit. The control unit 40 includes an observer unit 41 and an excitation command unit that are created by a controller design technique called the H∞ control and μ design method for the generalized plant shown in FIG. 42 etc. The observer 41 is input with the detected shaft torque value and the detected angular velocity value of the actual machine 30 with a dead time, and outputs the estimated value as the roller surface driving force. In the vibration command unit 42, a vibration command such as a random vibration command is superimposed and output to the control circuit of the inverter IV as a dynamometer torque current command.
Therefore, in a state where the test vehicle is mounted on the roller, the torque current command on which the vibration command by the vibration command unit 42 is superimposed is set as an input value, and the estimated roller surface driving force value by the observer unit 41 is set as an output value. In this case, the transfer characteristic of the roller surface driving force can be grasped from the dynamometer by obtaining the frequency characteristic and transfer function from the relationship between the input and the output.
That is, by changing the vibration command from the vibration command unit 42, the detected shaft torque signal and angular velocity signal are input to the observer unit 41 after each detection dead time, and the result is the gain and phase on the vertical axis. , The output Fx. From the input dynamometer torque command as a Bode diagram with frequency on the horizontal axis. Observe the characteristics of OBS.
At this time, for example, when the frequency is increased, a behavior occurs in which the gain and the phase change suddenly when the frequency is reached. By observing the behavior occurrence time with the output of the observer 41, it is possible to evaluate the estimated roller surface driving force.

  According to this embodiment, even when the test vehicle does not have a measuring device for measuring driving force such as a wheel torque meter or a six-component force meter, the estimated value of the roller surface driving force can be obtained by adding the observer 41 to the control unit 40. The frequency characteristics and transfer function for estimating the roller surface driving force can be obtained from the torque current command of the dynamometer.

The schematic diagram of the generalized plant model of the observer of this invention. The mechanical system model figure applied to the generalized plant model of an observer. Block diagram of the observer. The schematic diagram of the generalized plant model of the observer of this invention. The block diagram by the observer application to a dynamometer system. The block diagram of a chassis dynamometer system. The block diagram of the conventional roller surface driving force estimation circuit.

Explanation of symbols

Dy ... Dynamometer IV ... Inverter RP ... Roller surface estimated driving force estimation circuit R ... Roller EC (EC1, EC2) ... Encoder TM ... Torque meter 10 ... Controller 20 ... Mechanical system model 30 ... Actual machine (dynamometer system)
40 ... Control unit

Claims (3)

A chassis dynamometer system for controlling a dynamometer connected to a roller via a shaft by an inverter according to an output of a control unit, and estimating a roller surface driving force with an observer unit included in the control unit,
An observer generalized plant model is created by a controller design method called the H∞ control and μ design method for the observer unit and a mechanical system model for estimating the roller surface driving force provided in the observer unit,
The generalized plant model of the observer unit is a mechanical system model that inputs a roller surface driving force signal and a dynamometer torque command that are respectively weighted, and calculates a roller angular velocity signal, a shaft torque signal, and a dynamometer angular velocity signal. A torque meter characteristic model that inputs a shaft torque signal from a mechanical system model and outputs a shaft torque detection signal, and an encoder characteristic model that inputs a roller angular speed signal calculated by the mechanical system model and outputs a roller angular speed signal And
The sum of the torque detection signal generated via the torque meter characteristic model and the weighted shaft torque detection error signal is input as an observation signal to the controller as an axis torque detection signal and detected via the encoder characteristic model The sum of the measured roller angular velocity signal and the weighted dynamometer angular velocity observation noise is input as an observation signal to the controller as a detection signal of the dynamometer angular velocity, and the output of the controller and the weighted roller surface driving force signal A roller surface driving force estimation method, wherein the difference signal is a weighted roller surface driving force estimation signal. The mechanical system model for estimating the roller surface driving force includes a roller inertia moment element that calculates a roller angular velocity signal based on a sum of a rotational torque torque of the roller and a shaft torsion torque signal due to a vehicle driving force applied to the input roller surface; A dynamometer inertial moment element that calculates the angular velocity signal of the dynamometer based on the difference between the input dynamometer torque signal and the shaft torsional torque signal; The roller surface driving force estimation method according to claim 1, wherein each of the transfer functions of a spring stiffness element is provided . In a chassis dynamometer system for controlling a dynamometer connected to a roller via a shaft by an inverter based on a control signal from a control unit having an observer unit and a vibration command generation unit for estimating roller surface driving force,
The observer unit inputs the angular velocity signal detected by the chassis dynamometer system and the shaft torque signal of the shaft to calculate the estimated roller surface driving force, and the excitation command from the excitation command generation unit is a torque current command. And is configured to obtain the frequency characteristic and transfer function of the observer output from this superimposed torque current command,
The observer unit and the mechanical system model for estimating the roller surface driving force provided in the observer unit are an observer generalized plant model created by a controller design method called H∞ control and μ design method,
The generalized plant model of the observer section is a mechanical system model that inputs a weighted roller surface driving force signal and a dynamometer torque command and calculates a roller angular velocity signal, a shaft torque signal of a shaft, and a dynamometer angular velocity signal. A torque meter characteristic model that inputs a shaft torque signal from a system model and outputs a detection signal of a shaft torque, an encoder characteristic model that inputs a dynamometer angular speed from a mechanical system model and outputs a dynamometer angular speed signal,
The generalized plant model inputs the sum of the torque detection signal generated via the torque meter characteristic model and the weighted shaft torque detection error signal as an axis torque detection signal as an observation signal to the controller, and The sum of the dynamometer angular velocity signal detected via the encoder characteristic model and the weighted dynamometer angular velocity observation noise is input as an observation signal to the controller as a dynamometer angular velocity detection signal, and the output of the controller and the weighting A roller surface driving force estimation apparatus configured to use the roller surface driving force signal and the difference signal as a weighted roller surface driving force estimation signal .

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