JPH03165265A - Altitude difference measuring instrument - Google Patents

Abstract

PURPOSE:To easily measure the altitude difference between two points by detecting the pitch angle of a vehicle from the output of an accelerometer and the output of a speed meter, detecting the vertical speed of the vehicle from its pitch angle signal and the output of the speed meter, and differentiating the vertical speed signal and calculating the altitude difference between the two points where the vehicle travels. CONSTITUTION:This instrument is equipped with the accelerometer 10, the speed meter 20, and an arithmetic part 30. The speed meter 20 detects the speed V of the vehicle from the rotating speed of the wheel of the vehicle to obtain an output Sv corresponding to the speed V of the vehicle. The arithme tic part 30 detects the pitch angle of the vehicle from the output Sa of the accelerometer 10 and the output Sv of the speed meter 20, detects the vertical speed of the vehicle from the pitch angle signal and the output Sv of the speed meter 20, and integrates the vertical speed signal to calculate the altitude differ ence between the two points where the vehicle travels.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an elevation difference measuring device that measures an elevation difference between two points.

"Conventional Technology" Conventionally, optical surveying technology has been generally used to measure the difference in elevation between two points.

``Problem to be Solved by the Invention'' However, when measuring the elevation difference between two points by optical surveying as in the past, there is a disadvantage that special surveying equipment and specialized surveying techniques are required.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an elevation difference measuring device with a simple configuration that can easily measure the elevation difference between two points by simply mounting the device on a vehicle and driving the vehicle between the two points.

``Means for Solving the Problems'' This invention includes an accelerometer that is attached to a vehicle in the longitudinal direction of the vehicle and detects the acceleration of the vehicle, and a vehicle speed meter that detects the speed of the vehicle from the number of rotations of the wheels. At the same time, the pitch angle of the vehicle is detected from the output of the accelerometer and the output of the vehicle speedometer, the vertical speed of the vehicle is detected from the pitch angle signal and the output of the vehicle speedometer, and the vertical speed signal is detected. An arithmetic unit is provided which calculates the difference in elevation between two points traveled by the vehicle by integrating the difference in elevation.

"Function" According to the elevation difference measuring device of the present invention configured as described above, it is possible to simply drive a vehicle between two points without requiring any special surveying equipment or specialized surveying techniques. Elevation difference between two points can be easily measured.

Embodiment FIG. 1 shows an example of an elevation difference measuring device of the present invention, which includes an accelerometer 10, a vehicle speed meter 20, and a calculation section 30.

The accelerometer 10 is of the negative axis and is attached in the longitudinal direction of the vehicle 1 as shown in FIG.
, when the acceleration of gravity is g and the acceleration of the vehicle 1 is aC, the output Sa corresponding to the sum of a = g-sin θ and ac
is obtained. However, as shown in Figure 2, when the vehicle 1 travels from a low altitude point to a high altitude point, θ>0, and conversely, when the vehicle 1 travels from a high altitude point to a low altitude point, θ<0. .

The vehicle speed meter 20 detects the speed V of the vehicle 1 based on the number of rotations of the wheels of the vehicle 1, and can be one that is generally installed in a vehicle, and provides an output Sv corresponding to the speed 2 of the vehicle 1.

The calculation unit 30 detects the pitch angle θ of the vehicle 1 from the output Sa of the accelerometer 10 and the output Sv of the vehicle speedometer 20, and calculates the vertical speed Vv=of the vehicle 1 from the pitch angle signal and the output Sv of the vehicle speedometer 20. V・sinθ is detected and the vertical speed signal is integrated to calculate the altitude difference between two points where the vehicle 1 has traveled. Subtraction circuit 31 that subtracts the output Se
, an integration circuit 32 that integrates the output sb of the subtraction circuit 31, a subtraction circuit 33 that subtracts the output Sv of the vehicle speedometer 20 from the output Sc of the integration circuit 32, and the above constant multiplication that multiplies the output Sd of the subtraction circuit 33 by a constant K. A circuit 34, a constant multiplication circuit 35 that multiplies the output Se of the constant multiplication circuit 34 by the reciprocal 1/g of the acceleration of gravity g, a multiplication circuit 36 that multiplies the output Sp of the constant multiplication circuit 35 and the output Sv of the vehicle speed meter 20, and It is composed of an integrating circuit 37 that integrates the output Sq of the multiplier circuit 36.If the pitch angle θ of the vehicle 1 is zero, therefore, if the above a is zero, if the vehicle 1 is stopped and the speed ■ is zero, the acceleration Since ac is also zero, the output sb of the subtraction circuit 31, the output Sc of the integration circuit 32, and the subtraction circuit 33
The output Sd of becomes zero, and the output Se of the constant multiplier circuit 34 becomes zero.
will also become zero. When the vehicle 1 starts and accelerates when the pitch angle θ is zero, that is, when the above a is zero, that is, when the acceleration ac and the speed V are no longer zero, the output sb of the subtraction circuit 31 becomes the acceleration ac. The output Sc of the integration circuit 32 corresponds to the velocity V which is the integral value of the acceleration aC, and the output Sd of the subtraction circuit 33 becomes zero, so the output Se of the constant multiplication circuit 34
will be zero after all. After accelerating with the pitch angle θ being zero, when the vehicle l reaches a certain level of reach Vo,
Since the above a is zero and the acceleration a becomes zero, the output sb of the subtraction circuit 31 becomes zero, but the output Sc of the integration circuit 32 is maintained at the value corresponding to the velocity vO, so the subtraction The output Sd of the circuit 33 also becomes zero, and the output Se of the constant multiplier circuit 34 also becomes zero. That is, when the pitch angle θ is zero, the output Se of the constant multiplier circuit 34 is zero regardless of whether the vehicle 1 is stopped, accelerating, or traveling at a constant speed Vo. Become.

If the pitch angle θ changes while the vehicle 1 is running at a constant speed Vo, and therefore if the above 'a changes,
Since the acceleration ac is zero, the output sb of the subtraction circuit 31 corresponds to a, and the output Sc of the integration circuit 32 corresponds to the sum of the integral value of a to the speed VO. , the output Sd of the subtraction circuit 33 corresponds to the integral value of a, and the output Se of the constant multiplication circuit 34 corresponds to the integral value of a multiplied by a constant K. The output sb of the circuit 31 decreases from that corresponding to a, and the output Sc of the integration circuit 32, the output Sd of the subtraction circuit 33, and the output Se of the constant multiplication circuit 34
are respectively reduced from the above values, and at equilibrium, the output Se of the constant multiplier circuit 34 corresponds to a similar to the output Sa of the accelerometer lO, and the output sb of the subtraction circuit 31
becomes zero, the output Sd of the subtraction circuit 33 becomes equivalent to a/K, and the output Sc of the integration circuit 32 becomes ■0+a
/ It becomes equivalent to K.

In addition, if the pitch angle θ is constant, that is, the above a is constant, and the speed of vehicle 1 changes, that is, if vehicle l accelerates or decelerates from a constant speed of 0, subtraction is applied. The output sb of the circuit 31 corresponds to the acceleration aC, and the output Sc of the integrating circuit 32 becomes V o + a
/K is equivalent to the speed change ΔV, which is the integral value of acceleration ac, added, and the output Sd of the subtraction circuit 33 is equivalent to a/K, and the output of the constant multiplication circuit 34 is The output Se corresponds to a.

The same holds true when the pitch angle θ and the speed V change simultaneously, that is, the output Se of the constant multiplier circuit 34 always corresponds to a, including when the pitch angle θ is zero. However, when the pitch angle θ changes, there is a time delay in the output Se of the constant multiplier circuit 34 with respect to the change in a due to the change in the pitch angle θ, but this time delay is caused by making the constant K sufficiently thick ( It can be made sufficiently small by

In this way, the output Se of the constant multiplication circuit 34 is a-g-si
Since it corresponds to nθ, the output Sp of the constant multiplier circuit 35 corresponds to sinθ, and the output Sp of the constant multiplier circuit 35 corresponds to sinθ.
The output Sq corresponds to the vertical speed Vv=■・sinθ of the vehicle 1, and the output of the integrating circuit 37, that is, the output SO of the calculation unit 30 corresponds to the altitude difference between the two points where the vehicle 1 traveled. become.

Although not shown in the figure, in the case of adding the signal indicating the altitude of the travel start point of the vehicle 1, which is known in advance, to the output So of the integrating circuit 37, the added output is the altitude of the travel end point of the vehicle 1. You can get something that shows.

Note that the calculation unit 30 calculates the output Sa of the accelerometer 10 and the output Sv of the vehicle speedometer 20 depending on whether the output Sa of the accelerometer 10 and the output Sv of the vehicle speedometer 20 are obtained as analog signals or digital signals, or the output Sa of the accelerometer IO and the output Sv of the vehicle speedometer 20. Depending on whether Sv is extracted as an analog signal or a digital signal, it can be configured in either an analog configuration or a digital configuration, and in the case of a digital configuration, it can be configured by a computer.

"Effects of the Invention" As described above, according to the present invention, the elevation difference between two points can be easily measured by simply driving a vehicle equipped with a measuring device between the two points.

Furthermore, the altitude difference measuring device has a simple configuration consisting of an accelerometer, a vehicle speed meter, and a calculation section with a simple circuit configuration, and can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a system block diagram showing an example of an elevation difference measuring device of the present invention, and FIG. 2 is a diagram for explaining pitch angles of a vehicle, etc.

Claims (1)

[Claims] (1) An accelerometer that is attached to the longitudinal direction of the vehicle and detects the acceleration of the vehicle; a vehicle speedometer that detects the vehicle speed from the number of rotations of the wheels; a calculation unit that detects the pitch angle of the vehicle, detects the vertical speed of the vehicle from the pitch angle signal and the output of the vehicle speedometer, integrates the vertical speed signal, and calculates the elevation difference between two points where the vehicle has traveled; An elevation difference measuring device comprising: