JP4026482B2 - Control device for engine test equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine test apparatus, and more particularly to a control apparatus in a test apparatus.
[0002]
[Prior art]
FIG. 5 shows a configuration diagram of a control device in the engine test apparatus. A dynamometer 4 is connected to the engine 1 via a shaft 2 and a shaft torque meter 3, and the dynamometer 4 is driven by an inverter 5. 6 is a vehicle model section, which is composed of, for example, a 4-inertia spring model and a vertical vibration model with a suspension and a tire spring. The detected dynamometer speed signal or engine speed signal is inputted to the engine load torque command. It outputs to the torque control part 7 as (control point torque command).
[0003]
The torque control unit 7 calculates a torque current command value based on the input torque command, the detected shaft torque signal from the shaft torque meter 3 and the speed signal from the dynamometer 4, and sends the signal to the inverter 5. Output. The inverter 5 is subjected to torque current control so that the detected shaft torque signal follows the torque command value, and the engine load characteristics are simulated.
Patent Document 1 and the like are known as a control device in an engine test apparatus for simulating an engine load characteristic.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-98617 (FIGS. 1 to 4 and explanation thereof)
[0005]
[Problems to be solved by the invention]
In the control device shown in FIG. 5, a closed loop for torque control of shaft torque detection value → torque control unit 7 → inverter 5 → dynamometer 4 → shaft torque meter 3 is formed. On the outside, a closed loop is formed which is composed of the speed of the dynamometer 4 (or engine 1) → the vehicle model section 6 → the torque control section 7 → the speed detector (or engine speed detector) of the dynamometer.
[0006]
As described above, when the control device is configured by two closed loops, if the control response of the closed loop of the torque control system inside is slow, the load torque command value output from the vehicle model unit 6 is actually As a result, the load torque applied to the engine 1 is delayed, and as a result, the engine speed does not operate properly. In some cases, the engine speed hunting phenomenon or runaway occurs as shown in FIG. It becomes.
[0007]
FIG. 6 shows a simulation result when the frequency response of the torque control unit is 7 Hz and the gain is −3 dB in the control device of FIG. 5. According to this, an appropriate engine test is carried out until about 12 seconds, but the dynamometer torque shows an inappropriate vibration phenomenon after 12 seconds, and as a result, the intended engine test cannot be carried out. Have a problem.
[0008]
In Patent Document 1, due to the influence of the pulsating torque generated by the engine, the actual engine torque during operation of the engine bench system does not match the estimated value output by the torque map, and an error occurs. Although a solution based on the fact that a highly accurate simulated operation cannot be performed due to the influence is disclosed, the response delay of the torque control system is not mentioned.
[0009]
An object of the present invention is to provide a control device for an engine test apparatus that eliminates a control defect based on response delay.
[0010]
[Means for Solving the Problems]
In the first aspect of the present invention, an engine and a dynamometer are directly connected via a rotating shaft, and a rotational speed signal of the engine or dynamometer is detected and introduced into a vehicle model unit. Value is generated and output to the torque control unit, and the torque current command value is obtained using the load torque command value introduced by the torque control unit, the detected shaft torque value and the rotational speed signal, and the torque current command In what controls the dynamometer via an inverter according to the value,
An engine model unit that generates a model speed signal of the engine and outputs the model speed signal to a vehicle model unit, and a controller that inputs a deviation between the model speed signal of the engine and the rotation speed signal and converts it into a torque signal, The controller output signal and the engine load torque command value from the vehicle model part are added and output to the engine model part, and the engine model speed signal is calculated by the engine model part. Is.
[0011]
According to a second aspect of the present invention, the engine model section outputs an engine model speed signal calculated by 1 / (Je · s).
However, Je is the moment of inertia of the engine.
[0012]
A third aspect of the present invention is characterized in that the controller is a controller having integral characteristics or proportional characteristics.
[0013]
According to a fourth aspect of the present invention, an engine torque map representing the relationship between engine speed, throttle opening, and engine torque characteristics prepared in advance by measurement is provided, and the throttle opening signal of the throttle actuator and the rotation speed signal are stored in the engine torque map. And the engine torque value is estimated, the estimated value and the output value of the controller are added, and the addition signal and the load torque command value of the engine are added and output to the engine model unit. It is characterized by that.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing an embodiment of the present invention. The same or corresponding parts as those in the conventional block diagram shown in FIG.
Reference numeral 11 denotes a controller, and a transfer function G (s) in the controller 11 is an arbitrary controller having integral characteristics or proportional characteristics such as a PI controller (Kp + Ki / s). An engine model unit 12 outputs an engine model speed signal calculated by (1 / (Je · s)).
Here, Kp is a proportional coefficient, Ki is an integral coefficient, and Je is the moment of inertia of the engine.
Reference numerals 13 and 14 denote adders.
[0015]
In the configuration as described above, the engine 1 is controlled by a control circuit (not shown) so that there is no deviation between the throttle opening command and the detected throttle opening signal.
The torque control unit 7 calculates a torque current command based on the engine load torque command value input from the vehicle model unit 6 and the detected rotational speed signal and shaft torque signal, and according to the output. The dynamometer 4 is controlled through the inverter 5.
[0016]
The rotational speed of the dynamometer 4 (or engine) is detected by an encoder or the like and applied to the adding unit 13. An engine model speed signal is applied to the adding unit 13 from the engine model unit 12, and both signals are added with different polarities in the adding unit, and the deviation signal is input to the controller 11 to generate a torque signal. And output to the adder 14.
The engine load torque command value is applied to the adding unit 14 from the vehicle model unit 6. Therefore, the adding unit 14 adds both signals to the same polarity and then inputs them to the engine model unit 12 to input the engine. Find the model velocity signal. The model speed signal is applied to the adding unit 13 and is also applied to the vehicle model unit 6 as a speed signal and used for calculating the engine load torque command value.
[0017]
2A and 2B show simulation results of the control device of FIG. 1, where FIG. 2A is a torque diagram of a dynamometer and FIG. 2B is a speed diagram of an engine. As apparent from FIG. 2, the conventional dynamometer torque shown in FIG. 6 and inappropriate vibration in the engine speed do not occur, and the closed loop characteristic of the entire control system is improved. For this reason, even when the response of the closed loop of the shaft torque control system is slow, it is possible to perform an engine test by a closed loop having the vehicle model part on the outside thereof.
[0018]
FIG. 3 shows a configuration diagram of another embodiment. In the figure, an engine torque map 20 is provided in the embodiment shown in FIG. 1, and the output of the engine torque map and the output of the controller 11 are added to the same polarity in the adder 21. The added signal is added to the load torque command value in the adding unit 14 and input to the engine model unit 12.
The engine torque map 20 does not directly measure the engine torque during operation of the engine test apparatus, but is a graph representing the relationship between the engine speed, the throttle opening, and the engine torque characteristics prepared in advance by measurement. During operation of the engine test apparatus, the detected dynamometer speed or engine speed and the throttle opening signal of the throttle actuator are input to the engine torque map 20, and the engine torque is estimated from these input signals. The result is output to the adding unit 21 and added to the output G (s) of the controller 11. Others are the same as in FIG.
[0019]
According to the embodiment shown in FIG. 3, by adding an engine torque map, even when the response of the output G (s) of the controller 11 having an integral characteristic is slow, the engine model 1 / (Je · s) is quickly obtained. Can follow the speed of the dynamometer 4 or the engine 1. As a result, the engine speed input to the vehicle model 6 becomes faster, approaches the actual engine speed, and a more appropriate engine test is possible.
[0020]
FIG. 4 is a Bode diagram for comparing the prior art shown in FIG. 5 with the present invention shown in FIG. 3, where the solid line A is the present invention and the chain line B is the conventional one.
In the engine test apparatus, whether or not the hunting phenomenon as shown in FIG. 6 occurs is not determined by a single characteristic of the closed loop characteristic of the shaft torque control system or the characteristic of the vehicle model part. It can be seen that it is determined by a suitable combination of both.
[0021]
That is, when attention is paid to the frequency F (phase-360) point at which the signal is fed back in the same phase in the phase characteristics in FIG. 4, the gain of the line B representing the prior art exceeds 0 dB, but in the line A representing the present invention, It is less than 0 dB.
This indicates that the speed signal of the dynamometer 4 input to the vehicle model unit 6 diverges (instability phenomenon) with an increase in amplitude each time it goes around the outer closed loop including the vehicle model. Yes.
On the other hand, the present invention shows that the amplitude becomes small (stable) every time the closed loop is turned.
[0022]
【The invention's effect】
As described above, according to the present invention, the engine or dynamometer speed signal is not directly input to the vehicle model section, but the engine model speed signal output from the engine inertia moment model section is input to the vehicle model section. It is composed. As a result, the present invention improves the overall closed-loop characteristics including the vehicle model portion and improves the control stability.
Further, by adding control based on an engine torque map, it is possible to cope with a delay in response of the vehicle model unit, and it is possible to perform a more appropriate engine test.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a characteristic diagram for explanation, where (a) is a torque diagram of a dynamometer and (b) is an engine speed diagram.
FIG. 3 is a configuration diagram showing an embodiment of the present invention.
FIG. 4 is a Bode diagram for explanation.
FIG. 5 is a configuration diagram of a conventional engine test apparatus.
FIG. 6 is a characteristic diagram for explanation, where (a) is a torque diagram of a dynamometer, and (b) is an engine speed diagram.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Shaft 3 ... Shaft torque meter 4 ... Dynamometer 5 ... Inverter 6 ... Vehicle model part 7 ... Torque control part 11 ... Controller 12 ... Engine model part 20 ... Engine torque map

Claims (4)

The engine and dynamometer are directly connected to each other through a rotating shaft, and the rotational speed signal of the engine or dynamometer is detected and introduced into the vehicle model portion. The vehicle model portion generates an engine load torque command value to control the torque. The torque current command value is obtained using the load torque command value introduced by the torque control unit, the detected shaft torque value, and the rotational speed signal, and an inverter is passed through the torque current command value. To control the dynamometer
An engine model unit that generates a model speed signal of the engine and outputs the model speed signal to a vehicle model unit, and a controller that inputs a deviation between the model speed signal of the engine and the rotation speed signal and converts it into a torque signal, The controller output signal and the engine load torque command value from the vehicle model part are added and output to the engine model part, and the engine model speed signal is calculated by the engine model part. Control device for engine test equipment. 2. The engine test apparatus control device according to claim 1, wherein the engine model section outputs an engine model speed signal calculated by 1 / (Je · s).
However, Je is the moment of inertia of the engine. 3. The control device for an engine test apparatus according to claim 1, wherein the controller is a controller having integral characteristics or proportional characteristics. An engine torque map representing the relationship between engine speed, throttle opening, and engine torque characteristics prepared in advance by measurement is provided, and the engine torque value is calculated by introducing the throttle opening signal of the throttle actuator and the rotational speed signal into the engine torque map. The estimated value and the output value of the controller are added, and the addition signal and the load torque command value of the engine are added and output to the engine model unit. A control device for an engine test apparatus according to any one of claims 1 to 3.

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