JPS61111411A - Inclinometer - Google Patents

Abstract

PURPOSE:To prevent an inclinometer from the generation of an error by calculating the acceleration of a car by an acceleration operating circuit on the basis of a car speed signal generated from a car speed sensor, outputting a control signal in accordance with the acceleration and controlling a weight in accordance with the acceleration of the car. CONSTITUTION:When the acceleration is defined as alpha, torque F generated in a movable coil 8 is expressed by F=malphaXl on the basis of the relation between the mass (m) of the movable coil 8 and a distance from the center of gravity of the movable coil 8 to the axis of a driving shaft 6. When a braking current K'.I0 is inputted to an inclined angle detector 1, the control current K'.I0 is made to flow into the movable coil 8 through hair springs 12, 11 and torque F' is generated in the variable coil 8. Since the number of times of winding of the movable coil 8 is N, the torque F'=K'.I0XN is formed. When a variable resistor R7 is adjusted so that malphaXl=K'.I0XN is always formed, the torque makes it possible to brake the movement of the variable coil 8 by the braking current K'.I0 corresponding to the acceleration by varying the amplification K of an operational amplifier 21. Consequently, an real inclined angle can be always indicated without the influence of the acceleration of the car.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inclinometer that indicates the angle of inclination of a vehicle with respect to a road surface.

[Conventional technology]

2. Description of the Related Art Recently, various vehicles such as automobiles are equipped with inclinometers to quantitatively indicate the inclination with respect to the road surface on which they are traveling. Generally, this type of inclinometer detects the inclination angle of a vehicle to be measured (hereinafter referred to as a vehicle) with respect to the road surface based on the amount of rotation of a weight that rotates due to gravity according to the amount of inclination of the vehicle.

[Problem that the invention seeks to solve]

However, with such conventional inclinometers, when the vehicle speeds up or decelerates while driving, the weight rotates unnecessarily due to the influence of the acceleration, causing the tilt angle indication value to change. This has the disadvantage that errors may occur.

The present invention has been made to eliminate these drawbacks, and its purpose is to provide a relatively low-cost vehicle that does not cause errors due to the influence of acceleration even when the vehicle accelerates or decelerates. The aim is to provide an inclinometer.

[Failure to solve the problem]

In order to achieve such an object, the present invention includes a vehicle speed sensor that detects vehicle speed and generates a vehicle speed signal, calculates acceleration from the vehicle speed signal of this vehicle speed sensor, and brakes a weight according to this acceleration. The inclinometer is equipped with an acceleration calculation circuit that outputs a braking signal.

[Effect]

Therefore, according to the present invention, the acceleration calculation circuit calculates the acceleration based on the vehicle speed signal generated by the vehicle speed sensor, and outputs the braking signal in accordance with this acceleration, so that the weight is braked in accordance with the acceleration of the vehicle. can be done.

〔Example〕

Hereinafter, the inclinometer according to the present invention will be explained in detail.

FIG. 1 is a block diagram showing one embodiment of this inclinometer. In the figure, 1 is a tilt angle detector (not shown) that detects the tilt angle of the vehicle, 2 is a vehicle speed sensor that generates a vehicle speed signal corresponding to the vehicle speed, and 3 is a vehicle speed sensor that calculates acceleration based on the vehicle speed signal generated by the vehicle speed sensor 2. , an acceleration calculation circuit that outputs a braking signal for braking the movement of the weight of the tilt angle detector 1, which will be described later, according to this acceleration; 4 is a constant voltage power supply section that generates a constant voltage vc;
is constant voltage -■. It is generated and converted into a converter. Inclination angle' *m*, nvg2yaya. Engineering. Work. 8, a substantially rLJ-shaped pointer 6a fixed to the tip of the drive shaft 6, and a substantially "T"-shaped movable coil support piece γ made of a resin material fitted and fixed to the drive shaft 6; A moving coil 8 with a number of turns N supported and fixed on this moving coil support piece T,
The movable coil 8 is inserted through the hollow part of the
Aftershocks 11 and 12 are made of a ``''-shaped yoke 9, a magnet 10 provided across both ends of the open side of the yoke 9, and a conductive metal whose one end is insulated and fixed to the drive shaft 6.
, an adjustment gear 13 supported by a conductive metal rod on the whisker aftershocks 11 and 12, and an adjustment gear 1
The adjustment shaft 15 has an adjustment knob 15m that rotates the adjustment 9 ohm gear 14 to enable zero adjustment. Moving coil 8 of this tilt angle detector 1
is able to swing back and forth (left and right in the figure) about a drive shaft 6, and the mass m of this moving coil 8 is the weight of this tilt angle detector 1. Further, one end of the coil of the moving coil 8 is connected to one end of the beard aftershock 11 as shown in FIG. 1, and the other end of the coil of the moving coil 8 is connected to one end of the beard aftershock 12.

Then, the other end of Hige Aftershock 11 is grounded, and Hige Aftershock 12
The other end is connected to the output end of the acceleration calculation circuit 3.

On the other hand, vehicle speed sensor? 2 is a magnet disk 16 that rotates according to the speed of the vehicle, and a constant voltage power source 4 and a resistor R.

A reed relay 17 is connected to the reed relay 17 and is closed and controlled by the rotation of the magnetic disc 16.The pulse proportional to the vehicle speed generated by the reed IJL/-17 is a real-time response of the acceleration calculation circuit 3. The signal is input to a WF/'/converter (hereinafter referred to as F/V-1 converter) 18 and a delay type F7'V converter (hereinafter referred to as F/V-I converter) 19, respectively.

Also, F/V-I: ff7 converter 18 and F/V-1
The other input terminal of the T converter 19 is connected to the constant voltage power supply section 4.
Since the constant voltage vc of the F/V-I converter 18 and the F/V-I converter 19 are now directly input, the output voltage e and C2 corresponding to the input pulse proportional to the vehicle speed are It is now output. The F/V-1 converter 18 and the F/V-11 converter 19 each include a resistor R, a capacitor C1, and a resistor R.
2 and a capacitor C2, the output voltage C8 output from the F/V-■ converter 19 is more passive than the output voltage e output from the F/V-1 converter 18. The phase is delayed by the difference in the time constant of the integrating circuit. That is, the output voltage e2 output from the F/V-n converter 19 is greater than the output voltage e1 output from the F/V-1 converter 18 by ΔT = (C+Ra C1Rt) Ko
(1) Ko: The phase is delayed by a proportionality constant. Therefore, the output voltage e is equal to the output voltage e corresponding to the vehicle speed.

By delaying by ΔT, the acceleration α of the vehicle can be defined as. Note that the resistor R8 of the F/V-11 converter 19 is variable, and by finely adjusting this resistor R8, the output output from the F/V-n converter 19 when the vehicle continues to run at a constant speed can be adjusted. Voltage e2 is F/V-1
It can be set in advance so that it can be made to the same level as the output voltage e1 output from the converter 18.

By doing this, it is possible to eliminate errors caused by the characteristics of the F'/V-1 converter 18 and the F/V-If converter 19.

The output voltage e1 output from the F/V-I converter 18 is input to the inverting input terminal of the differential amplifier 20 via the resistor R8, and the output voltage e3 output from the F/V-n converter 19 is input to the inverting input terminal of the differential amplifier 20 via the resistor R8. Resistor R81 via R6
The voltage is divided by 62' and inputted to the non-inverting input terminal of the differential amplifier 20. The difference between the output voltages e and 1 input to the inverting input terminal and the non-inverting input terminal is amplified by the differential-1 amplifier 2G to produce the output voltage e.

becomes. This amplified output voltage e. is differential amplifier 2
Since the output of 0 is fed back to the inverting input terminal via the resistor R3', it is expressed as follows. Here, the resistor R4 connected to the non-inverting input terminal of the differential amplifier 20 is variable, and when the output voltages e and e input to the differential amplifier 20 are at the same level, that is, when the The output voltage e output from the differential amplifier 20 when the vehicle continues to run at a constant speed.

can be preset to zero.

By doing so, it is possible to eliminate errors caused by the characteristics of the differential amplifier 20. At this time, the resistance value of the resistor R2 is set to be approximately equal to the resistor R3, so it can be expressed as follows. Therefore, this output voltage e.

is a voltage value proportional to the acceleration α shown in equation (2). Furthermore, when the vehicle is stopped, the F/V-1 converter 18
and F/V-1f. Although the outputs of the converter 19 are zero, an offset voltage occurs due to the characteristics of the differential amplifier 20, so e is set in advance by a resistor R5. It can be adjusted so that =0.

Therefore, the output voltage e output from the differential amplifier 20.

is input to the non-inverting input terminal of the buffer operational amplifier 21, amplified by the amplification factor υ, and sent to the next stage current booster 22 via the resistor R8. Note that a resistor R6 and a variable resistor R7 are connected to the inverting input terminal of the operational amplifier 21 so that the output of the current booster 22 can be fed back, and the amplification factor K can be adjusted in advance by the variable resistor R9. It is now possible to do so. Further, the current booster 22 is composed of an NPN transistor 22a and a PNP transistor 22b, and the transistors 22a, 22b, ! : is connected to the resistor R8, and each emitter is connected to the other end of the whisker aftershock 12 of the inclination angle detector 1 described above.

Further, the collector of the transistor 22a is connected to the constant voltage power supply section 4.
The collector of the transistor 22b is connected to the -vct source line of the wholesale converter 5.

This current booster 22 can amplify the output voltage -el) output from the operational amplifier 21 to obtain K·Io (K': current amplification factor of the current booster 22) as a braking current. ing. Such FV-
1 converter 18, FV-It converter 19, differential amplifier 20, operational amplifier 21, and current booster 22 constitute acceleration calculation circuit 3. Incidentally, power supply voltages vc and -ve are inputted to the differential amplifier 20 and the operational amplifier 21 from the constant voltage power supply section 4 and the n+ converter 5, respectively.

The operation of the inclinometer of the present invention will be explained below. First, before explaining the operation, a case where only the inclination angle detector 1 is installed and used in a vehicle will be explained. That is, the tilt angle detector 1
When driving on flat ground while accelerating speed with only one installed in the vehicle,
The movable coil 8 of the inclination angle detector 1 rotates rearward about the drive shaft 6 as the vehicle speeds up. As a result, the pointer 6 & fixed to the tip of the drive shaft 6 rotates downward, and begins to indicate the angle of inclination by the angle graduated on an indicator plate (not shown). However, this displayed inclination angle is a predetermined angle that corresponds to the acceleration due to speed increase of the vehicle (hereinafter simply referred to as "speed increase"), and does not indicate the true inclination angle. An error has occurred in the speed increase variation. This inclination angle error is corrected when the vehicle speed is maintained at a constant speed for a predetermined period of time or longer, since no acceleration is applied to the vehicle. However, if the vehicle accelerates or decelerates even slightly, it will increase or decrease acceleration (hereinafter simply referred to as deceleration).
Under the influence of this, the angle of inclination indicated by the pointer 6a no longer indicates the true angle of inclination. The torque generated in the moving coil 8 due to this acceleration or deceleration is calculated by the mass m of the moving coil 8 and the distance t from the center of gravity of the moving coil 8 to the axis of the drive shaft 6, where α represents the acceleration or deceleration. It is determined by the function of . That is, the torque generated in the moving coil 8 is expressed as F=mα×t...1 (5). Of course, even when the vehicle travels uphill or downhill, the inclination angle detector 1 is affected by the torque F generated by this acceleration or deceleration. Therefore, by braking the unnecessary rotation of the movable coil 8 due to this torque F, the tilt angle detector 1 can indicate the true tilt angle.

The following will explain a case in which the inclinometer of this embodiment is mounted on a vehicle and the vehicle is traveling on flat ground while increasing speed. That is, when the vehicle starts running, the speed sensor 2 generates a pulse proportional to the speed of the vehicle. And this pulse is F
/V-1 converter 18 and F/V-1f converter 19
The output voltage e1 corresponding to the input voltage proportional to the vehicle speed from the F/V-■ converter 18 is input to the F/V-
I[The phase is ΔT than the output voltage e1 from the converter 19
The output voltages e2 corresponding to the input signals delayed by the same amount (see formula 1) are respectively outputted. Figure 3 shows this vehicle at 0.
These are the output characteristics of the output screw e-work and @2 when the speed is increased at 6G = 5.88 m/s. From this characteristic diagram, if the voltage values of the output voltages e1 and e after a predetermined time has elapsed after running are 1 and V, then the acceleration α is given by equation (2) above.

On the other hand, F/V-1=+ inverter 18 and F/V-[[
Output voltages e1 and e2 output from converter 19
are input to the inverting input terminal and non-inverting input terminal of the differential amplifier 20 via resistors R8 and R1, respectively. At this time, the variable resistor R2 is the output voltage e output from the differential amplifier 20 when the vehicle continues to travel at a constant speed. Since it is preset to zero, the output voltage e. is as shown in equation (4) above.

This is the case when the output' voltages e and @2 are V and V2. Therefore, this e. is input to the operational amplifier 21 as an output voltage value proportional to the acceleration α shown in equation (6). Then, the operational amplifier 21 amplifies the signal by an amplification factor and inputs it to the current booster 22. At this time, Ke
According to the characteristic diagram of FIG. 3, o is > e 2, so it becomes a negative voltage and is applied to the current booster 22. To this negative voltage -
The transistor 22b is turned on by eo, and the braking current '.Io is input to the tilt angle detector 1.

Then, when this braking current '·Io is input to the tilt angle detector 1, this braking current '·Io flows through the movable coil 8 via the full-beard keys 12 and 11, and the movable coil 8 receives a torque voltage. occurs. Since the number of turns of the moving coil 8 is N, this torque y is F'=K'・I. XN...(8
). Since this torque y can be adjusted by varying the amplification factor K of the operational amplifier 21, it can be made equal to F in the above equation (5) by adjusting the variable resistance R of the operational amplifier 21. That is, 1mαXt='・
If the variable resistor R7 is adjusted so that IoxN is always maintained at
This makes it possible to brake the movement of the moving coil 8, and the inclinometer always continues to indicate the true angle of inclination.

The above has been described for the case where the vehicle is running on flat ground while accelerating, but even when the vehicle is running while decelerating, the braking current is affected in the same way. The movement of the moving coil 8 can be braked according to the deceleration.

Figure 4 shows this vehicle at 0.6 G = 5.88 m/s
F/V-1 converter 18 and F when decelerating with
These are the output characteristics of the output voltages e and e2 output from the /V-It converter 19. From this characteristic diagram, 120K
The voltage values of output voltages e1 and e2 when a predetermined time has elapsed after decelerating from m/H constant speed running are vl and v, respectively.
2, the output voltage e output from the differential amplifier 20 as in equation (7) above. is R8/eo=-1 (v knee ■2)! 8～. , 7.11.4°. ,,□zpv,<v
, so this output voltage e0 becomes a positive voltage and is input to the operational amplifier 21. When the operational amplifier 21 outputs a positive output voltage -eo which has been amplified twice, the transistor 22m of the current booster 22 is turned on by the positive voltage -co. And this transistor 22a
A braking current corresponding to the deceleration is sent to the tilt angle detector 1 through
・Io is input. This braking current is is the braking current input during speed increase.

The current is in the opposite direction, and this braking current is Therefore, a torque y in the opposite direction to that at the time of speed increase is generated in the moving coil 8. Therefore, the movable coil 8 is braked in the opposite direction to that during speed increase, and even if the movable coil 8 attempts to rotate forward excessively during deceleration, that movement is prevented.
This inclinometer always indicates the true angle of inclination. The above was explained using examples of when the vehicle accelerates on flat ground and when it decelerates on flat ground.
It is also possible to similarly indicate the true angle of inclination even when speeding up or decelerating on an uphill or downhill slope.

Figure 5 shows the speed increase and braking current. Figure 6 shows the relationship between deceleration and braking current.

〔Effect of the invention〕

As explained above, according to the inclinometer according to the present invention, the acceleration calculation circuit calculates the acceleration based on the vehicle speed signal generated by the vehicle speed sensor, and outputs the braking signal in accordance with this acceleration.

The weight can be braked according to the acceleration of the vehicle, and even if the vehicle accelerates or decelerates, the true angle of inclination can always be indicated without being affected by the acceleration.

Further, if the acceleration calculation is performed using a simple discrete circuit, there is no need to use a time processing device such as a microcomputer, and the cost can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the inclinometer according to the present invention, Fig. 2 is a schematic perspective view showing the mechanism of the inclination angle detector used in this inclinometer, and Fig. 3 is a block diagram showing an embodiment of the inclinometer. Output voltages e1 and e2 when the vehicle equipped with it is accelerated at 0.6 G
Figure 4 shows the output characteristics of a vehicle equipped with this inclinometer.
．． Figure 5 shows the output voltage e and output characteristics of e3 when decelerating at 6G. Figure 6 shows the relationship between deceleration and braking current. FIG. 1... Tilt angle detector, 2... Acceleration calculation circuit,
3... Vehicle speed sensor, 8... Moving coil, 18...
...F/V-■ Converter, 19...F/V-
1 converter, 20... differential amplifier, 21... two operational amplifiers, 22... current booster.

Claims (1)

[Claims] An inclinometer that uses gravity acting on a weight to indicate the angle of inclination of the vehicle to be measured with respect to the road surface includes a vehicle speed sensor that detects the vehicle speed and generates a vehicle speed signal, and an acceleration sensor that detects the vehicle speed and generates a vehicle speed signal. An inclinometer comprising an acceleration calculation circuit which calculates the acceleration and outputs a braking signal for braking the weight according to the acceleration.