CN109799489B - Altimeter simulator and simulation method thereof - Google Patents

Abstract

The invention discloses an altimeter simulator and a simulation method, wherein the simulator comprises a pre-stage amplification module, a post-stage amplification module, a local oscillator module, a binary delay line switch matrix, a pre-mixer, a post-mixer, a link A first switch, a link A second switch, a link B first switch and a link B second switch, wherein the link A first switch is connected with the link A second switch to form a first-stage altitude simulation link A, and the link B first switch is connected with the link B second switch to form a second-stage altitude simulation link B. The invention effectively reduces the simulation time delay of 'absolute 0 m' of the altimeter simulator, reduces the simulation time delay to 2.5ns, further reduces the actual simulation height corresponding to the 'absolute 0 m' to 0.375m, effectively improves the altitude simulation precision of the altimeter simulator, ensures that the altimeter simulator is more accurate and reasonable when the altimeter simulator is used for checking the altimeter, and is beneficial to improving the test precision of the altimeter.

Description

A kind of altimeter simulator and its simulation method

technical field

The invention relates to the field of radio altitude measurement, in particular to an analog altimeter simulator and a simulation method.

Background technique

The radio altimeter is an essential device on the aircraft, it is used to measure the distance from the aircraft to the ground surface. The principle is that the transmitter and receiver of the radio altimeter are installed on the aircraft, and the height from the ground to the aircraft is determined by measuring the round-trip electromagnetic wave propagation delay time. The altimeter simulator is the key equipment for the comprehensive performance test of the radio altimeter. It can continuously simulate the echo signals of the radio altimeter at various altitudes, so as to complete the altitude test of the altimeter.

At present, the altimeter simulators on the market are mainly divided into two types, one is a digital altimeter simulator, and the other is an analog altimeter simulator. The digital altimeter simulator uses a digital delay chip internally to store the signal, and then transmits it after storing for a certain period of time. The advantage is that it is small in size and can be easily simulated at any height. The disadvantage is that when the digital chip processes signals, the delay time cannot be too short. Signals, the stray is serious and difficult to handle; the analog altimeter simulator, the principle is to use the surface acoustic wave delay line as the main delay device, its accuracy depends on the plate making accuracy, it is very easy to ensure the consistency and accuracy of the product, no need The additional correction compensation facilitates the formation of a binary delay line switch matrix. The so-called binary delay line switch matrix means that its height is set in a binary arrangement, and a small number of delay lines are used to achieve a large-scale, high-precision, continuous high-level simulation.

The analog altimeter simulator adopts the surface acoustic wave delay line technology. The delay time of the existing surface acoustic wave delay line can be at least 53ns (the delay time of 53ns is converted into a corresponding height of about 8m). The way of winding and binary combination can greatly improve the height simulation accuracy of the altimeter simulator. However, the working frequency of the SAW delay line is generally at least 800MHz, and the combination of wire winding and binary must be connected to the up and down conversion components. Connecting the device will increase the delay time and increase the lower limit of the "absolute 0m" of the altimeter simulator. The so-called "absolute 0 meters" means that when each altimeter simulator is set to 0, in theory, the analog signal has no delay, but the actual analog signal in the simulator will have a certain delay time T due to the device and wiring, so that the height When the watch simulator tests the altimeter, because of the delay time T, the actual simulated height corresponding to the 0 value when testing the altimeter is always greater than 0m, and cannot reach the absolute 0m value. For example, for the existing 0-8000m altimeter simulator, the simulation delay of "absolute 0m" is 20ns (corresponding to the actual height of 3m), and the simulation delay of "absolute 0m" of the 127m altitude simulator is 10ns (corresponding to the actual height of 1.5m) or so. Therefore, an altimeter simulator with a simulated height of 0-8000 meters is actually a height simulation of 3-8003m, and an altimeter simulator with a simulated height of 0-127m is actually a height simulation of 1.5-128.5m.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an altimeter simulator and a simulation method thereof in order to solve the above-mentioned problems.

In a first aspect, the present invention provides an altimeter simulator, including a pre-amplifier module, a post-amplifier module, a local oscillator module, a binary delay line switch matrix, a pre-mixer, a post-mixer, and a link A first. switch, the second switch of link A, the first switch of link B, the second switch of link B, the pre-amplifier module is connected to the pre-mixer, and the pre-mixer is connected to the binary delay line A switch matrix is connected, the binary delay line switch matrix is connected to the post-mixer, the post-mixer is connected to the post-stage amplifying module, and the local oscillator module is respectively connected to the pre-mixer and the post-mixer. The first switch of the link A is set in the pre-amplifier module, and the first switch of the link B is set between the pre-amplifier module and the pre-mixer, so The second switch of link A is set in the post-amplification module, the second switch of link B is set between the post-mixer and the post-amplification module, the first switch of link A is The switch is connected to the second switch of the link A to form a first-level high-level analog link A, and the first switch of the link B is connected to the second switch of the link B to form a second-level high-level analog link B .

Further, the post-stage amplifier module includes a post-stage amplifier, a filter and a post-stage attenuator, the post-stage amplifier is connected to the filter, the filter is connected to the post-stage attenuator, and the chain The second switch of path A is arranged between the filter and the post-stage attenuator.

Further, the pre-amplifier module includes a pre-stage attenuator and a pre-stage amplifier, and the first switch of the link A is arranged between the pre-stage attenuator and the pre-stage amplifier.

Further, the first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B are all single-pole double-throw switches.

In a second aspect, the present invention provides a method for simulating altitude, the method includes: initializing a simulator, setting a main link for altitude simulation, setting a first-level altitude simulation link A, and setting a second-level altitude simulation link B, Prepare for height simulation:

Select the first-level altitude simulation link A, switch the first switch of link A and the second switch of link A to link A, and start the first-level altitude simulation;

Select the second-level high analog link B, switch the first switch of link A and the second switch of link A to the main link, and switch the first switch of link B and the second switch of link B to the link B, start the second-level altitude simulation;

Select the high-simulation main link, switch the first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B to the main link, and start the high-simulation main link simulation.

Further, the first switch of link A and the second switch of link A are switched between the main link and link A, and the first switch of link B and the second switch of link B are switched between the main link and the link A. switch between link B.

The beneficial effects of the present invention are:

Compared with the existing altimeter simulator, the present invention adds two altitude simulation links, and connects the first switch of link A and the second switch of link A to form a first-level altitude simulation link A and link B. The first switch is connected with the second switch of link B to form a second-level highly analog link B.

The "absolute 0m" of the altimeter simulator corresponds to the selection of the first-level altitude simulation link A. In addition, in order to improve the accuracy of the altitude step, the second-level altitude simulation link B is set. Using the first-level altitude simulation link A can reduce the simulation delay to 2.5ns (corresponding to the actual altitude of 0.375m), and using the second-level altitude simulation link B to achieve a simulation delay of 6.8ns (corresponding to the actual altitude of 1.05m) m), the present invention effectively reduces the "absolute 0m" simulation delay of the altimeter simulator, so that the "absolute 0m" simulation delay is reduced to 2.5ns (corresponding to the actual height of 0.375m), that is, the "absolute 0m" The actual simulation height of the altimeter is reduced to 0.375m, which effectively improves the height simulation accuracy of the altimeter simulator, making it more accurate and reasonable when testing the altimeter, which helps to improve the test accuracy of the altimeter, and makes the altitude of the aircraft more accurate for engineers. (or operator) has a more intuitive reflection, allowing engineers to better control the altitude and safe driving of the aircraft.

attached drawing

Fig. 1: the principle structure diagram of the simulator of the present invention;

Fig. 2: the principle structure diagram of binary delay line switch matrix in the simulator of the present invention;

Figure 3: The flow chart of the simulation method of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and examples, and embodiments of the present invention include but are not limited to the following examples.

As shown in FIG. 1, an altimeter simulator provided by the present invention includes a pre-amplifier module, a post-amplifier module, a local oscillator module, a binary delay line switch matrix, a pre-mixer, a post-mixer, a link A first switch, link A second switch, link B first switch, link B second switch, the pre-amplifier module is connected to the pre-mixer, the pre-mixer is connected to the binary delay line switch matrix, the binary The delay line switch matrix is connected to the post-mixer, the post-mixer is connected to the post-amplifier module, the local oscillator module is respectively connected to the pre-mixer and the post-mixer, and the first switch of the link A is set in the pre-amplifier module Inside, the first switch of link B is set between the pre-amplifier module and the pre-mixer, the second switch of link A is set in the post-amplifier module, and the second switch of link B is set between the post-mixer and the post-mixer. Between the stage amplification modules, the first switch of link A is connected to the second switch of link A to form a first-stage high-level analog link A, and the first switch of link B is connected to the second switch of link B to form the second stage Link B is highly simulated.

The first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B are SPDT switches. The pre-amplifier module includes a pre-stage attenuator and a pre-stage amplifier, and the first switch of the link A is arranged between the pre-stage attenuator and the pre-stage amplifier. The post-stage amplifier module includes a post-stage amplifier, a filter and a post-stage attenuator. The post-stage amplifier is connected to the filter, the filter is connected to the post-stage attenuator, and the second switch of Link A is set between the filter and the post-stage attenuator. between. It should be noted that in the prior art, the filter is connected after the rear-stage attenuator, but in the present invention, in order to ensure that the time delay of the surface acoustic wave signal passing through the link A is minimized, the filter is moved before the rear-stage attenuator. , because the actually measured delay of the signal passing through the filter is 4 ns, while the delay passing through the attenuator is 1.2 ns, the delay of the signal passing through the filter is 2.8 ns longer than that of the attenuator, so link A chooses to pass Post attenuator instead of filter. In addition, in the present invention, in order to reduce the time delay, the time delay of the filter is optimized, and the time delay of the signal passing through the filter has been optimized to 2.9ns.

As shown in FIG. 3 , a method for simulating altitude provided by the present invention includes: initialization of the simulator, setting up a main link for altitude simulation, setting up a first-level altitude simulation link A, and setting up a second-level altitude simulation link B, Prepare for height simulation:

Select the first-level altitude simulation link A, switch the first switch of link A and the second switch of link A to link A, and start the first-level altitude simulation; select the second-level altitude simulation link B, switch the link Switch the first switch of link A and the second switch of link A to the main link, switch the first switch of link B and the second switch of link B to link B, and start the second-level height simulation; select the height simulation For the main link, the first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B are all switched to the main link, and the high-simulation main link simulation is started.

The link A first switch and the link A second switch switch between the main link and the link A, and the link B first switch and the link B second switch switch between the main link and the link B.

As shown in Figure 1, the simulation path of the existing altimeter simulator has only one main link, and its path is: preamplifier module→premixer→binary delay line switch matrix→postmixer→postamplifier module. It is worth noting that during its "absolute 0m" simulation, as shown in Figure 2, all switches in the binary delay line switch matrix are switched to the channel. For example, the simulation delay of "absolute 0m" of the 0-8000m altimeter simulator in the prior art is shown in Table 1:

Table 1

It can be seen from Table 1 that using the existing technology, the simulation delay of the "absolute 0m" of the 0-8000m altimeter simulator is 20ns (corresponding to the actual height of 3m). Therefore, the actual simulated height of the 0-8000m altimeter simulator is 3-8003m.

The first-level altitude simulation link A of the present invention is the "absolute 0m" simulation path of the altimeter simulator, and the simulation path is: front-stage attenuator → rear-stage attenuator. The second switch of A is switched to link A, and the first-level altitude simulation is started. The simulation delay of the first-level altitude simulation link A is shown in Table 2:

Table 2

The total delay of the signal passing through the first-level altitude simulation link A is 2.5ns (corresponding to the actual altitude of 0.375m), that is to say, a 0-8000m altimeter simulator adopts the technical solution of the present invention and its "absolute 0m" The corresponding actual height value is 0.375m. Compared with the existing actual height value of “absolute 0m”, which is 3m, the simulation delay of absolute 0m is greatly reduced, and the actual height value corresponding to “absolute 0m” is further reduced. Analog Accuracy.

In order to improve the step accuracy of the analog height, a second-level height analog link B is added. The path of the signal to link B is: pre-amplifier module → post-amplifier module. The analog delay table is shown in Table 3:

table 3

As can be seen from Table 3, the simulation delay of the signal going to the second-level altitude analog link B is 6.8ns (corresponding to the actual altitude of 1.05m). The setting of the second-level altitude analog link B can increase the height step accuracy. Then, if further height steps are required, select the height to simulate the main link, and realize the binary step of the analog height through the binary delay line switch matrix in the main link.

To sum up, the present invention is provided with the first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B at a suitable position on the main link of the altimeter simulator, It is equivalent to adding two high-level analog links. By connecting the first switch of link A and the second switch of link A, a first-level high-level analog link A is formed, and the first switch of link B and the second switch of link B are formed. The switch is connected to form the second-level high analog link B. The first-level altitude simulation link A is used as the simulation path of "absolute 0m" of the altimeter simulator, which changes the simulation path of the existing "absolute 0m" of the altimeter simulator, greatly reduces the simulation delay, and makes the altimeter simulation The actual simulation height corresponding to the "absolute 0m" of the controller is reduced to 0.375m. In addition, a second-level height simulation link B is set to improve the step accuracy of the height simulation.

Claims (4)

1. an altimeter simulator, is characterized in that: comprise pre-amplifier module, post-amplifier module, local oscillator module and binary delay line switch matrix, pre-mixer, post-mixer, link A first switch , the second switch of link A, the first switch of link B, the second switch of link B, the pre-amplifier module includes a pre-stage attenuator and a pre-stage amplifier, and the post-stage amplifying module includes a post-stage amplifier, a filter and a post-stage attenuator; the pre-amplifier and the pre-mixer are connected through the first switch of the link B, the pre-mixer is connected with the binary delay line switch matrix, and the binary delay line The line switch matrix is connected to the post-mixer, the local oscillator module is respectively connected to the pre-mixer and the post-mixer, and the first switch of the link A is arranged in the pre-amplifier module, The first switch of the link B is set between the pre-amplifier module and the pre-mixer, the second switch of the link A is set in the post-amplifier module, and the post-mixer It is connected to the post-stage amplifier through the second switch of the link B, and the first switch of the link A is connected to the second switch of the link A to form a first-level high-level analog link A. The link The first switch of B is connected to the second switch of the link B to form a second-level high-level analog link B; the post-stage amplifier is connected to the filter, and the filter and the post-stage attenuator pass through the The link A is connected to the second switch; the pre-stage attenuator is connected to the pre-amplifier through the link A first switch. 2. The altimeter simulator according to claim 1, wherein the first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B are all SPDT switch. 3. a kind of method that adopts the described altimeter simulator of claim 1 to simulate altitude, it is characterized in that: simulator initialization, set altitude simulation main link, set first level altitude simulation link A, set second level altitude Simulate link B, ready for height simulation: Select the first-level altitude simulation link A, switch the first switch of link A and the second switch of link A to link A, and start the first-level altitude simulation; Select the second-level high analog link B, switch the first switch of link A and the second switch of link A to the main link, and switch the first switch of link B and the second switch of link B to the link B, start the second-level altitude simulation; Select the high-simulation main link, switch the first switch of link A, the second switch of link A, the first switch of link B, and the second switch of link B to the main link, and start the high-simulation main link simulation. 4. The method for simulating altitude according to claim 3, wherein the first switch of link A and the second switch of link A are switched between the main link and link A, and the link B The first switch and link B second switch switches between the main link and link B.

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