JP2006064522A - Integration processing apparatus for measurement signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive, high-precision integration processing apparatus for a measurement signal which detects an inclination angle of a static vehicle and an inclination angle of a dynamic vehicle without requiring a high-sensitivity acceleration sensor. <P>SOLUTION: The apparatus comprises: a roll rate sensor 1 for detecting a roll rate of a vehicle; a DC offset processing means 2 for removing a DC offset component superimposed on an inclination angle of the vehicle by performing integration processing on the detection output of the roll rate sensor 1 or a divergence phenomenon of integration processing; and an inclination angle correction means 3 for correcting a static inclination angle of the vehicle in accordance with the time of start of the vehicle from an inclined road on the basis of the output of the DC offset processing means 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a measurement signal integration processing device, and more particularly to a measurement signal integration processing device suitable for use in a rollover determination device or the like that integrates information from a roll rate sensor and calculates a tilt angle.

In general, in a rollover determination device, an output signal of a roll rate (angular velocity) sensor is integrated to obtain a vehicle inclination angle. However, an offset signal in an extremely low frequency band is detected by the drift of the sensor itself in the output signal of the roll rate sensor. Therefore, when this signal is directly integrated, there is a problem that an offset component is superimposed on the integration processing result and diverges due to the influence of the DC signal component, so that an accurate inclination angle cannot be obtained.
Therefore, conventionally, a high-pass filter is used to extract a DC offset component included in the target signal, and the signal is added to the target signal to remove the DC component. However, this removal process cannot completely remove the DC component. Therefore, when this signal is completely integrated for a long time, it often causes divergence. Therefore, normally, an integration circuit that performs incomplete integration by waiting for a predetermined discharge time constant in series with the DC offset elimination circuit is arranged. However, if incomplete integration is used, there is a problem that the tilt angle is measured smaller than the actual time according to the discharge time constant if there is no change in the tilt angle for a long period of time.

In the measurement of the static tilt angle when there is no change in the tilt angle for a long time, for example, there is one in which the tilt is obtained with reference to the gravitational acceleration using an acceleration sensor (for example, Patent Document 1). And Patent Document 2).
In addition, there is a method of avoiding the divergence phenomenon by detecting a collision phenomenon that occurs when the vehicle travels and then performing a short integration process (see, for example, Patent Document 3).

JP 2001-260701 A JP 2003-170806 A JP-A-8-104199

However, in the case of Patent Document 1 and Patent Document 2 described above, it is effective for measurement when the vehicle is stopped, but has a drawback that it cannot be measured when traveling with impact, and a high-sensitivity acceleration sensor that measures the gravitational acceleration level is required. Therefore, there was a problem that the cost was increased.
Further, in the case of the above-mentioned Patent Document 3, it is effective for the determination of the collision that occurs when the vehicle travels, but in the rollover determination, the integration process is continued even when the vehicle continuously travels on a slope with a relatively low roll rate. Since it is necessary to obtain the tilt angle, there is a problem that it cannot be used (is not effective).

  The present invention has been made to solve the above-described problems, and is inexpensive and highly accurate that can detect a static vehicle inclination angle and a dynamic vehicle inclination angle without requiring a high-sensitivity acceleration sensor. An object of the present invention is to obtain an integration processing apparatus for measurement signals.

  A measurement signal integration processing device according to the present invention includes a roll rate sensor 1 that detects a roll rate of a vehicle, and a DC offset component or integration that integrates a detection output of the roll rate sensor 1 and superimposes it on a vehicle tilt angle. DC offset processing means 2 for removing the process divergence phenomenon, and tilt angle correction for correcting the static tilt angle of the vehicle in response to the start of the vehicle from the ramp based on the output of the DC offset removing means 2 Means 3 is provided.

  Since the present invention does not remove the information of the gently changing inclination angle close to the DC band, it becomes possible to measure the inclination angle of the vehicle with high accuracy, and the inclination angle when the vehicle is stopped from the IG / ON / OFF or the vehicle speed. Is stored and added to the integration processing function when the vehicle is started, so that a static inclination angle can be obtained without using information of a conventional acceleration sensor, so that the measurement accuracy is improved, the configuration is simplified, and the cost is reduced. There is an effect that the cost can be reduced.

An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a block diagram showing a configuration of a measurement signal integration processing device according to Embodiment 1 of the present invention.
In FIG. 1, the measurement signal integration processing device according to the present embodiment includes a roll rate sensor 1 as roll rate detection means for detecting a roll rate (angular velocity) Rr (deg / sec), and an output signal of the roll rate sensor 1. In other words, the roll rate Rr is (completely) integrated to remove the DC offset component superimposed on the vehicle tilt angle detection signal or the divergence phenomenon of the integration process, so that the static tilt angle Ra (s) of the vehicle, that is, for a long time. DC offset processing means 2 that outputs the inclination angle Ra (s) when there is no change in the inclination angle of the vehicle, and the static inclination of the vehicle that is output from the DC offset processing means 2 in response to starting from the ramp Inclination angle correcting means 3 for correcting the angle Ra (s).

  The DC offset processing unit 2 integrates the roll rate Rr from the roll rate sensor 1 and performs a weighted averaging process on the output signal Ra (roll angle (deg)) from the integration processor 21. And an output signal from the integration processing unit 21 indicated by the roll rate Rr from the roll rate sensor 1 or the broken line a, which removes the extremely low frequency offset (hereinafter referred to as DC offset) component. A roll rate determining unit 23 that determines the level of Ra and controls the operation / pause of the weighted average averaging unit 22 is provided.

  Further, the inclination angle correcting means 3 monitors the vehicle speed of the vehicle and determines whether the vehicle is stopped / running for a certain time (t1) or ON / OFF of the ignition switch (hereinafter referred to as IG / ON / OFF). When the output from the vehicle motion determination unit 31 represents stoppage or IG · OFF, the inclination angle Ra obtained on the output side of the weighted addition averaging processing unit 22 at that time is stored as the inclination angle Ra (s). When the IG / ON or the vehicle starts running in response to the output of the unit 32 and the vehicle operation determining unit 31, that is, when starting, the inclination angle Ra (s) stored in the storage unit 32 is integrated. An inclination angle setting unit 33 that adds the inclination angle Ra (s) stored in the storage unit 32 to the integration processing in the integration processing unit 21. Obtain.

  As an example, the vehicle tilt angle Ra (s) stored in the storage unit 32 is stored as the tilt angle Ra immediately after IG · OFF or X seconds after the vehicle speed is 0 km / h. The timing at which the inclination angle Ra (s) stored in the storage unit 32 is set in the integration processing unit 21 by the inclination angle setting unit 33 is, for example, 3 seconds after IG · ON or the vehicle exceeds 0 km / h. When you do.

Next, the operation will be described with reference to FIGS.
First, FIG. 2 shows a method of DC offset processing in the DC offset processing means 2, and the roll rate Rr from the roll rate sensor 1 is integrated by the integration processing unit 21 of the DC offset processing means 2 (Ra = ∫Rrdt). ) And supplied to the weighted average averaging processing unit 22. On the other hand, the roll rate Rr from the roll rate sensor 1 is also supplied to the roll rate determination unit 23, and the roll rate determination unit 23 determines whether or not the value of the roll rate Rr is smaller than a predetermined value n. When the value of Rr is smaller than the predetermined value n, the weighted averaging process unit 22 is activated to activate the DC offset processing function.

  FIG. 3 shows an example of a static inclination angle correction method in the inclination angle correction means 3 of FIG. 1. Here, the IG / ON / OFF is monitored and the IG / ON / OFF is determined. As an example, the vehicle operation determination unit 31 includes an IG / ON / OFF determination unit 31b that determines IG / ON / OFF from a signal from an input terminal 31a connected to an ignition switch (not shown), This is a case where a gate circuit, such as an AND circuit 31c, for opening and closing the gate based on the output of the IG / ON / OFF determination unit 31b and the output of the storage unit 32 is used.

  In FIG. 3, the roll rate Rr from the roll rate sensor 1 is integrated by the integration processing unit 21 (Ra = ＲRrdt) and supplied to the weighted addition average processing unit 22, and the weighted addition average processing unit 22 integrates the processing unit 21. The weighted average averaging process is performed on the output signal Ra from the output signal to remove the DC offset component. When the determination of the IG / ON / OFF determination unit 31b is IG-OFF, the weighted addition average processing unit 22 at that time The inclination angle Ra obtained on the output side is stored in the storage unit 32 that stores the inclination angle Ra (s). When the determination of the IG / ON / OFF determination unit 31b is ON, the AND circuit 31c opens the gate and the inclination angle Ra (s) stored in the storage unit 32 is supplied to the inclination angle setting unit 33. The inclination angle setting unit 33 sets the inclination angle Ra (s) stored in the storage unit 32 as the inclination angle Ra (s) at the time of starting the vehicle in the integration processing unit 21 when IG / ON, that is, integration. The inclination angle Ra (s) stored in the storage unit 32 is added to the integration process in the processing unit 21.

In this case, the detection of the IG / ON / OFF timing in the IG / ON / OFF determination unit 31b can be realized by monitoring the power supply of an airbag ECU (not shown).
Therefore, in the case of FIG. 3, the inclination angle at the time of IG · ON / OFF is stored and added to the integration processing function at the start, so that the static inclination angle can be obtained without using the information of the conventional acceleration sensor. Can be sought.

  FIG. 4 shows another example of the static inclination angle correction method in the inclination angle correction means 3 of FIG. 1. Here, the vehicle speed and its continuation including the case where the vehicle speed is 0 km / h are shown. In this case, the vehicle operation determining unit 31 monitors the time and determines whether the vehicle is stopped or started. In this case, the vehicle operation determining unit 31 determines whether the vehicle is stopped or started from the output of a vehicle speed sensor (not shown) applied to the input terminal 31a. This is a case where the vehicle speed detection unit 31d to be determined and a gate circuit that opens and closes the gate based on the output of the vehicle speed detection unit 31d and the output of the storage unit 32, for example, an AND circuit 31c.

  In FIG. 4, the roll rate Rr from the roll rate sensor 1 is integrated by the integration processing unit 21 (Ra = ∫Rrdt) and supplied to the weighted addition average processing unit 22, and the weighted addition average processing unit 22 integrates the processing unit 21. When the vehicle speed detection unit 31d determines that the vehicle speed is 0 km / h, that is, when the vehicle is stopped, the weighted addition average processing is performed on the output signal Ra from The storage unit 32 stores the inclination angle Ra obtained on the output side of the processing unit 22 as the inclination angle Ra (s). When the vehicle speed detection unit 31d determines that the vehicle speed is not 0 km / h, that is, when the vehicle starts, the AND circuit 31c opens the gate and the inclination angle Ra (s) stored in the storage unit 32 is inclined. The inclination angle setting unit 33 is supplied to the angle setting unit 33. When the vehicle is stopped, the integration processing unit 21 uses the inclination angle Ra (s) stored in the storage unit 32 as the inclination angle Ra (s) at the start of the vehicle. That is, the inclination angle Ra (s) stored in the storage unit 32 is added to the integration processing in the integration processing unit 21.

  Therefore, in the case of FIG. 4, as in the case of FIG. 3, the static inclination angle can be obtained without using the information of the conventional acceleration sensor, and the vehicle speed and the duration thereof are monitored, Since signal waiting, idling, constant speed traveling, and the like can be determined, the frequency of addition correction is increased, and the measurement accuracy of the tilt angle is improved.

Thus, in the first embodiment, when the roll rate Rr is small, that is, when the tilt angle is small, the DC offset removal process (including the removal process of the divergence phenomenon of the integration process) is performed, and the roll rate Rr becomes large. By canceling the direct current removal processing, information on the inclination angle that gradually changes close to the direct current band is not removed, so that the vehicle inclination angle can be measured with high accuracy.
In addition, the inclination angle when the vehicle is stopped is stored from IG / ON / OFF or vehicle speed, and is added to the integration processing function when starting the vehicle, thereby obtaining the static inclination angle without using information from a conventional acceleration sensor. Therefore, the configuration can be simplified and the cost can be reduced.

Embodiment 2. FIG.
FIG. 5 is a block diagram showing the configuration of the measurement signal integration processing device according to the second embodiment of the present invention. In FIG. 5, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
In the present embodiment, the weighted averaging processing unit 22 in FIG. 1 of the first embodiment is substantially replaced with the previous stage of the integration processing unit 21.
In FIG. 5, the DC offset processing means 2A performs a weighted averaging process on the roll rate Rr from the roll rate sensor 1 and removes its ultra-low frequency offset (hereinafter referred to as DC offset) component. The processing unit 22, the integration processing unit 21 that integrates the output signal Rr ₁ from the weighted addition averaging processing unit 22, and the output signal Ra from the roll rate sensor 1 indicated by the roll rate Rr or the broken line a. And a roll rate determining unit 23 for controlling the operation / pause of the weighted addition averaging processing unit 22.

  In addition, the inclination angle correction means 3 includes a vehicle operation determination unit 31, a storage unit 32, and an inclination angle setting unit 33 similar to those in FIG. 1. Here, the storage unit 32 outputs an output from the vehicle operation determination unit 31. In the case of representing stop or IG · OFF, it is the same as the case of FIG. 1 except that the inclination angle Ra obtained on the output side of the integration processing unit 21 at that time is stored as the inclination angle Ra (s). Accordingly, the entire operation is substantially the same as that of FIG. 1 except that the operations of the weighted addition averaging processing unit 22 and the integration processing unit 21 are changed, and the description thereof is omitted.

  As described above, in the second embodiment, as in the first embodiment, it is possible to measure the vehicle tilt angle with high accuracy and to obtain a static tilt angle without using information from a conventional acceleration sensor. Therefore, the configuration can be simplified and the cost can be reduced.

Embodiment 3 FIG.
FIG. 6 is a block diagram showing a configuration of a measurement signal integration processing device according to Embodiment 3 of the present invention. In FIG. 6, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
In the present embodiment, when the DC offset drift of the roll rate Rr of the roll rate sensor 1 is large, the DC offset component is also removed from the DC offset component of the roll rate Rr. removing the DC offset component, it obtains a signal of the roll rate Rr ₁ after the DC offset removal, with respect to the roll rate Rr ₁ after the DC offset removal, and performs the same processing as in the first embodiment.

In FIG. 6, the first DC offset processing for removing the output signal of the roll rate sensor 1, that is, the DC offset component of the roll rate Rr, between the roll rate sensor 1 and the DC offset processing means 2 as the second DC offset processing means. DC offset processing means 4 is provided as means.
The DC offset processing means 4 performs a weighted averaging process on the roll rate Rr from the roll rate sensor 1 to remove the DC offset component, and a roll rate from the roll rate sensor 1. A roll rate determination unit 42 that determines the level of Rr and controls the operation / pause of the weighted addition averaging processing unit 41. Other configurations are the same as those in FIG.

Next, the operation will be described with reference to FIG.
First, FIG. 7 shows a method of direct current offset processing in the direct current offset processing means 4 and direct current offset processing means 2, and the roll rate Rr from the roll rate sensor 1 is used as a weighted addition average processing unit 41 of the direct current offset processing means 4. To supply. On the other hand, the roll rate Rr from the roll rate sensor 1 is also supplied to the roll rate determination unit 42, and the roll rate determination unit 42 determines whether the value of the roll rate Rr, that is, the shake of the running vehicle is smaller than the threshold value m. When the value of the roll rate Rr is smaller than the predetermined value m, the weighted addition averaging processing unit 41 is operated to activate the DC offset processing function.

Then, the output Rr ₁ of the weighted average averaging unit 41 is supplied to the DC offset processing means 2 at the next stage, and thereafter, integration processing is performed by the integration processing unit 21 of the DC offset processing means 2 as in the case of FIG. (Ra = ∫Rr ₁ dt) and supply the result to the weighted averaging processor 22. On the other hand, the output Rr ₁ of the weighted average averaging processing unit 41 is also supplied to the roll rate determining unit 23, and the roll rate determining unit 23 is traveling to the value of the output Rr ₁ of the weighted average averaging processing unit 41, that is, the DC offset component. values shaking adding the vehicle to determine whether the threshold n ₁ is less than or of operating a weighted addition average processing unit 22 when the value of the output Rr ₁ weighted averaging processor 41 is less than the threshold value n ₁ Then, the DC offset processing function is activated.

  Further, the inclination angle correcting means 3 monitors the vehicle speed of the vehicle, and the output from the vehicle operation determination unit 31 for determining whether the vehicle stops or travels for a certain time (t1) or IG / ON / OFF indicates the stop or IG / OFF. Then, the inclination angle Ra obtained on the output side of the weighted average averaging processing unit 22 at that time is sequentially stored in the storage unit 32 as the inclination angle Ra (s), and the inclination angle setting unit 33 outputs the output to the vehicle operation determination unit 31. In response, when the IG • ON or the vehicle starts running, that is, at the time of starting, the inclination angle Ra (s) stored in the storage unit 32 is set in the integration processing unit 21. That is, the inclination angle Ra (s) stored in the storage unit 32 in the integration process in the integration processing unit 21 is added to the process of the integration processing unit 21.

Thus, in the third embodiment, the signal level is determined by the signal of the roll rate Rr ₁ after the DC offset process, and the operation / pause of the DC offset removal after the integration process can be determined. The deviation due to the signal polarity is eliminated in the determination, which can contribute to improvement in stability and accuracy of the DC offset processing.

Embodiment 4 FIG.
FIG. 8 is a block diagram specifically showing the configuration of the measurement signal integration processing device according to the fourth embodiment of the present invention. In FIG. 8, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.
In the present embodiment, as an example, specific examples of the weighted addition average processing unit 41, the integration processing unit 21, and the weighted addition average processing unit 22 in FIG. 6 are shown.
In FIG. 8, the weighted addition average processing unit 41 includes a subtractor 41 a that subtracts a reference signal described later from the roll rate Rr from the roll rate sensor 1, that is, the output signal Vi (t) of the roll rate sensor 1, and the subtractor The roll rate comparison / determination unit 41b for determining whether or not the roll rate Rr from 41a is smaller than a predetermined value m (deg / sec), and when the roll rate Rr is smaller than the threshold value m, that is, when the DC offset removal function is activated. When the roll rate Rr is set to the value N1 of the weighting factor k and the roll rate Rr is larger than the threshold value m, that is, when the DC offset removal function is stopped, the weighting factor setting unit 41c that sets the value of the weighting factor k to 0, and the weighting factor setting The output of the unit 41c and an output Vref (t-1) of a shift register 41e described later are added, and a reference signal Vref (t) is added to the output side. Output by the adder 41d and the output t of the reference signal Vref (t), which is the output of the adder 41d, are shifted one by one as the reference signal Vref (t−1) as a reference signal Vref (t−1). Shift register 41e.

  Further, the integration processing unit 21 outputs the output of the weighted averaging processing unit 41 from the roll rate Rr from the roll rate sensor 1, that is, the output signal Vi (t) of the roll rate sensor 1, that is, the reference signal Vref (from the adder 41d). a subtractor 21a that subtracts t) and outputs the output signal Vo (t) as a correction signal to the output side thereof, an adder 21b that adds the output of the subtractor 21a and the output of a shift register 21c described later, Based on the output of the subtractor 21d and the output of the tilt angle offset setting unit 34, the number of data samples is shifted one by one and input to the adder 21b, and the weighted addition average processing unit 22 is output from the output of the adder 21b. Of the reference signal Vref (t) from the adder 22d, and outputs it as an inclination angle Ra to the output side thereof; Provided. The tilt angle offset setting unit 34 sets Ra offset when IG / ON, and this Ra offset substantially represents the case where the vehicle is stopped in an inclined state, for example, when IG / ON. The vehicle inclination angle Ra or the vehicle inclination angle Ra at a vehicle speed of 0 km / h is shown.

Further, the weighted addition average processing unit 22 includes a subtractor 22a that subtracts a reference signal (to be described later) from the inclination angle Ra from the subtractor 21d of the integration processing unit 21, that is, the output signal Vi (t) from the subtractor 21d. An inclination angle determination unit 22b that determines whether or not the inclination angle Ra from the subtractor 22a is smaller than the threshold value n ₂ (deg), and when the inclination angle Ra is smaller than the threshold value n ₂ , that is, when the DC offset removal function is activated. is set to a value N2 of the weighting factor k, if the inclination angle Ra is larger than the threshold value n _2, i.e. at rest the DC offset removal function, and the weighting coefficient setting unit 22c that the value of the weight coefficient k is set to 0, the weighting factor An adder 22d that adds an output of the setting unit 22c and an output Vref (t-1) of a shift register 22e described later, and outputs the result to the output side as a reference signal Vref (t); A shift register 22e that shifts the sample number t of the data of the reference signal Vref (t), which is the output of the adder 22d, one by one and inputs it to the subtracter 22a and the adder 22d as the reference signal Vref (t-1); Is provided.

Next, the operation will be described.
First, in the weighted addition average processing unit 41, the reference signal input from the adder 41d via the shift register 41e is subtracted from the roll rate Rr from the roll rate sensor 1 by the subtractor 41a, and the roll rate comparison / determination unit 41b. The roll rate comparison / determination unit 41b determines whether the roll rate Rr from the subtractor 41a is smaller than the threshold value m (deg / sec). Based on the determination result, the weight coefficient setting unit 41c When the rate Rr is smaller than the threshold value m, that is, when the DC offset removing function is activated, the value N1 of the weighting factor k is set. When the roll rate Rr is larger than the threshold value m, that is, when the DC offset removing function is stopped, the weighting factor k is set. Set the value of to 0.

  The adder 41d adds the output of the weight coefficient setting unit 41c and the output Vref (t-1) of the shift register 41e, and outputs a reference signal Vref (t) to the output side. The reference signal Vref (t) from the adder 41d is supplied to the shift register 41e, and the shift register 41e shifts the number of data samples t by one to obtain the reference signal Vref (t−1) as a subtractor 41a and The data is input to the adder 41d. Further, the reference signal Vref (t) from the adder 41d is supplied to the subtracter 21a of the next-stage integration processing unit 21. That is, the weighted average processing unit 41 functions to remove the DC offset component when the roll rate Rr is smaller than the threshold value m.

Next, in the integration processing unit 21, the subtractor 21a subtracts the output of the weighted addition averaging processing unit 41, that is, the reference signal Vref (t) from the adder 41d, from the output signal Vi (t) of the roll rate sensor 1. The output signal Vo (t) is output to the output side as a correction signal. The output of the subtractor 21a is supplied to one input terminal of the adder 21b, and the other input terminal of the adder 21b receives data based on the output of the subsequent subtractor 21d and the output of the tilt angle offset setting unit 34. The output of the shift register 21c that shifts the number of samples one by one is supplied and added, and the added output is supplied to the subtractor 21d. Note that the tilt angle offset setting unit 34 sets Ra offset when the IG is turned on for the shift register 21c.
The subtractor 21d subtracts the output of the weighted average averaging processing unit 22, that is, the reference signal Vref (t) from the adder 22d, from the output of the adder 21b, and outputs the result to the output side as the tilt angle Ra.

In addition, in the weighted addition average processing unit 22, the reference signal input from the adder 22d via the shift register 22e is subtracted from the output of the integration processing unit 21 by the subtractor 22a, that is, the inclination angle Ra from the subtractor 21d. Is supplied to the tilt angle determination unit 22b, and the tilt angle determination unit 22b determines whether the tilt angle Ra from the subtractor 22a is smaller than a threshold value n ₂ (deg), and sets a weighting factor based on the determination result. In the unit 22c, when the inclination angle Ra is smaller than the threshold value n, that is, when the DC offset removal function is activated, the value of the weighting factor k is set to N2, and when the inclination angle Ra is larger than the threshold value n, that is, the DC offset removal function. The value of the weight coefficient k is set to 0 at the time of rest.

  The adder 22d adds the output of the weighting coefficient setting unit 22c and the output Vref (t-1) of the shift register 22e, and outputs a reference signal Vref (t) to the output side. The reference signal Vref (t) from the adder 22d is supplied to the shift register 22e, and the shift register 22e shifts the number t of data samples one by one to obtain a reference signal Vref (t-1) as a subtractor 22a and The data is input to the adder 22d. Further, the reference signal Vref (t) from the adder 22d is supplied to the subtracter 21a of the previous integration processing unit 21. In other words, the weighted averaging processor 22 functions to remove the DC offset component when the inclination angle Ra is smaller than the threshold value n.

Here, the weighted addition averaging process of the following formulas (1) and (2) is used for the DC offset removal function in the weighted addition averaging processing units 41 and 22.
Vref (t) = (1-k) Vref (t-1) + kVi (t)
= Vref (t-1) + kVi (t) .Vref (t-1)
(1)
Vo (t) = Vi (t) −Vref (2)

In addition, in the weighting factor setting unit 41c of the weighted addition averaging processing unit 41 and the weighting factor setting unit 22c of the weighting addition averaging processing unit 22, the value of the weighting factor k is set to k = N ( Specifically, N1 is set in the weighting factor setting unit 41c and N2 in the weighting factor setting unit 22c), and k = 0 is set at the time of rest. As the weighting factor k, for example, the following N value is used. The integration is realized by a bit shift instruction.
k ⁼ 1/2 -12 ⁼ 0.00024414
k = 1/2 ⁻⁹ = 0.0019531
k = 1/2 ⁻⁶ = 0.015625
k = 1/2 ⁻⁵ = 0.03125
k = 1/2 ^-4 = 0.0625
k ⁼ 1/2 -3 ⁼ 0.125
Therefore, by changing the value N of the weighting factor k as described above when the DC offset removal function is operated, the measurement signal can be made a signal waveform centered on the zero point, and the DC offset is removed. Measurement accuracy can be improved.

  In this manner, in the fourth embodiment, the normal DC offset processing can be realized by analog and digital low-pass filters, and in that case, the operation and the pause are repeated frequently at time intervals within the time constant of the filter. The signal waveform is distorted and accurate tilt angle measurement cannot be performed. However, in the configuration of this embodiment described above, the DC offset function is activated when the signal level is small, and therefore there is a discontinuity in the measured value. The influence is small, and therefore it can be measured accurately. Further, the integration time is realized by a bit shift instruction, that is, by shifting the number of data samples one by one with a shift register, the calculation time can be shortened as compared with a so-called float calculation.

Embodiment 5. FIG.
In the present embodiment, only when the roll rate Rr is equal to or less than a certain threshold immediately after IG · ON, the value of the weighting factor k is increased, and the DC offset component of the roll rate Rr from the roll rate sensor 1 is removed early, After that, the value of the weighting factor k is set small and the DC offset component is gently removed. Note that the circuit configuration may be the same as that shown in FIG. 8, for example, and therefore the description thereof is omitted here.

  In this way, in the fifth embodiment, the initial processing is completed at high speed, and the DC offset removal processing is performed only when the roll rate Rr and the inclination angle Ra are equal to or less than a certain value. Measurement error in running on an inclined road surface can be reduced. Also, only when the roll rate Rr and the inclination angle Ra are equal to or less than a certain threshold value, the weighting factor k is set to a small value and the DC offset component is gently removed, so that it is not removed when an effective signal level is generated in the angle information ( It does not affect).

It is a block diagram which shows the structure of the integration processing apparatus of the measurement signal by Embodiment 1 of this invention. FIG. 6 is a block diagram for explaining the operation of the DC offset processing means of the measurement signal integration processing device according to Embodiment 1 of the present invention; It is a block diagram which shows an example of the method of static inclination-angle correction | amendment in the measurement signal integration processing apparatus by Embodiment 1 of this invention. It is a block diagram which shows the other example of the method of static inclination-angle correction | amendment in the measurement signal integration processing apparatus by Embodiment 1 of this invention. It is a block diagram which shows the structure of the integration processing apparatus of the measurement signal by Embodiment 2 of this invention. It is a block diagram which shows the structure of the integration processing apparatus of the measurement signal by Embodiment 3 of this invention. It is a block diagram for use in explanation of the operation of the DC offset processing means of the measurement signal integration processing device according to Embodiment 3 of the present invention. It is a block diagram which shows the structure of the integration processing apparatus of the measurement signal by Embodiment 4 of this invention.

Explanation of symbols

  1 roll rate sensor, 2, 2A DC offset processing means, 3 tilt angle correction means, 4 DC offset processing means, 21 integration processing section, 21a, 21d subtractor, 21b adder, 21c shift register, 22 weighted addition average processing section 22a subtractor, 22b tilt angle determination unit, 22c weight coefficient setting unit, 22d adder, 22e shift register, 23 roll rate determination unit, 31 vehicle operation determination unit, 31b IG / ON / OFF determination unit, 31c AND circuit, 31d Vehicle speed detection unit, 32 storage unit, 33 tilt angle setting unit, 34 tilt angle offset setting unit, 41 weighted addition averaging processing unit, 41a subtractor, 41b roll rate comparison determination unit, 41c weight coefficient setting unit, 41d adder, 41e shift register, 42 roll rate determination unit.

Claims (6)

Roll rate detecting means for detecting the roll rate of the vehicle;
DC offset processing means for integrating the detection output of the roll rate detection means to remove the divergence phenomenon of the DC offset component or integration processing superimposed on the vehicle tilt angle;
A measurement signal integration processing device comprising: an inclination angle correcting means for correcting a static inclination angle of the vehicle in response to a start of the vehicle from the ramp based on the output of the DC offset removing means.   The DC offset processing means performs a weighted averaging process on the output signal from the integration processing part to remove the DC offset component, and determines the roll rate level from the roll rate detecting means. The measurement signal integration processing apparatus according to claim 1, further comprising: a roll rate determination unit that controls operation / pause of the weighted average averaging processing unit.   The inclination angle correcting means monitors the vehicle speed and determines whether the vehicle stops or travels for a certain period of time or turns on / off the ignition switch, and the output from the vehicle operation determining unit turns off the ignition switch or the ignition switch. A storage unit for storing the inclination angle obtained on the output side of the weighted averaging processing unit at that time, and the storage unit when the ignition switch is turned on or the vehicle starts in response to the output of the vehicle operation determination unit The measurement signal integration processing device according to claim 2, further comprising: an inclination angle setting unit configured to set the inclination angle stored in the integration processing unit.   The DC offset processing means performs a weighted averaging process on the roll rate detected by the roll rate detecting means to remove the DC offset component, and a roll rate of the roll rate from the roll rate detecting means. The measurement signal integration processing device according to claim 1, further comprising: a roll rate determination unit that determines a level and controls operation / pause of the weighted addition averaging processing unit.   The inclination angle correcting means monitors the vehicle speed and determines whether the vehicle stops or travels for a certain period of time or determines whether the ignition switch is on or off, and the output from the vehicle operation determination unit turns off the ignition switch or the ignition switch. A storage unit that stores the inclination angle obtained on the output side of the integration processing unit at that time, and stored in the storage unit when the ignition switch is turned on or the vehicle starts in response to the output of the vehicle operation determination unit The measurement signal integration processing device according to claim 4, further comprising a tilt angle setting unit configured to set the tilt angle in the integration processing unit.   The direct current offset processing means includes first direct current offset processing means for removing the direct current offset component when the roll rate detected by the roll rate detection means is smaller than a predetermined value or the divergence phenomenon of the integration process, and the first direct current offset processing means. 2. The second DC offset processing means for removing the DC offset component or the divergence phenomenon of the integration processing when the inclination angle obtained by integrating the output of the DC offset processing means is smaller than a predetermined value. The measurement signal integration processing device according to claim 5.

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