Damping link parameter determination method for isolating harmful temperature feedback

Abstract

The invention relates to a method for determining parameters of a damping link for isolating harmful temperature feedback. The method comprises the following steps: step 1, acquiring a closed air temperature value T1 around an inertial platform and an ambient temperature T2 around an inertial platform frame; 2, rotating the inertial platform to obtain the maximum variable quantity dT2 of the ambient temperature T2 around the inertial platform frame; 3, determining a damping target according to the temperature sensitivity of the inertial element and the precision of the inertial navigation system; step 4, determining target time t according to actual rotation conditions; 5, according to a first-order system response curve c (t) = 1-e (-t / T), a damping link time constant T is obtained through calculation, and therefore a transfer function of a damping link is determined. According to the invention, the harmful temperature disturbance problem can be fundamentally solved, and the temperature control precision is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of inertial navigation systems and relates to a method for determining damping link parameters, in particular to a method for determining damping link parameters for isolating harmful temperature feedback. Background Art

[0002] In the inertial navigation system, the inertial measurement element installed on the inertial platform body is a heat-generating device. The function of the inertial platform temperature control is to ensure the stability of the temperature field inside the inertial platform by controlling the air temperature around the inertial platform. In high-precision inertial navigation equipment, the inertial measurement element installed on the inertial platform body is very sensitive to changes in the temperature field of the space in which it is located. Therefore, multi-level temperature control is usually used to solve the contradiction between high precision and high environmental adaptability.

[0003] Due to the lateral temperature gradient in the ambient temperature field, the temperature field around the inertial measurement element will eventually fluctuate in the rotating state. This temperature that affects the temperature control accuracy enters the temperature control feedback network, which is referred to as "harmful temperature feedback" in this article. In order to solve the impact of harmful temperature and achieve temperature uniformity inside the inertial platform, it is usually adopted to increase the number of temperature sensors and adopt smoothing to reduce its impact. However, this method increases the burden of hardware and wiring, and the effect that can be achieved is also limited, and it cannot fundamentally solve the problem. Another method is to increase the number of temperature control levels, gradually reduce the harmful temperature, and finally achieve the purpose of temperature stability inside the inertial platform. This method has the disadvantages of high cost and high power.

[0004] Therefore, the present invention proposes a method for determining the parameters of a damping link for isolating harmful temperature feedback, which can overcome the above problems.

[0005] After searching, no prior art documents identical or similar to the present invention were found. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a method for determining the parameters of a damping link for isolating harmful temperature feedback. By designing a damping link, harmful temperature is blocked from entering the temperature feedback channel at the source, the problem of harmful temperature disturbance is fundamentally solved, and the accuracy of temperature control is improved.

[0007] The present invention solves the practical problem by adopting the following technical solutions:

[0008] A method for determining damping link parameters for isolating harmful temperature feedback comprises the following steps:

[0009] Step 1, obtain the temperature value T1 of the enclosed air around the inertial platform and the ambient temperature T2 of the inertial platform frame;

[0010] Step 2: Rotate the inertial platform to obtain the maximum change dT2 of the ambient temperature T2 around the inertial platform frame;

[0011] Step 3: Determine the damping target according to the temperature sensitivity of the inertial element and the accuracy of the inertial navigation system;

[0012] Step 4: Determine the target time t according to the actual rotation conditions;

[0013] Step 5: According to the first-order system response curve c(t)=1-e(-t / T), the damping link time constant T is calculated, thereby determining the transfer function of the damping link.

[0014] Moreover, before isolating the harmful temperature feedback, the temperature value of the enclosed air around the inertial platform in step 1 is T1≈40°C and the ambient temperature around the inertial platform frame is T2≈35°C;

[0015] Moreover, the maximum change of the ambient temperature T2 of the inertial platform frame in step 2 is dT2=2°C;

[0016] Moreover, the specific method of step 3 is:

[0017] Determine the damping target based on the temperature sensitivity of the inertial element and the accuracy of the inertial navigation system

[0018] (1-F)*(1 / dT2)*dT0;

[0019] dT0 is the temperature control target fluctuation value.

[0020] Moreover, the transfer function of the damping link in step 5 is Gn=K / (Ts+1), and the time constant of the damping link is calculated to be T=676s;

[0021] Moreover, the step 5 further includes the following steps:

[0022] Step 6: Design the damper and install it on the inertial platform frame.

[0023] Advantages and beneficial effects of the present invention:

[0024] 1. The present invention blocks the influence of harmful temperature from the source and improves the uniformity of the temperature inside the inertial platform.

[0025] 2. The present invention improves the temperature control effect without increasing the number of temperature sensors, thus reducing the hardware and wiring burden of the inertial navigation system.

[0026] 3. The present invention does not increase the temperature control level of the inertial navigation system and has the characteristics of low cost and low power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is the electrical principle diagram and main signal distribution diagram of the present invention. DETAILED DESCRIPTION

[0028] The following further describes the embodiments of the present invention:

[0029] A method for determining damping link parameters for isolating harmful temperature feedback comprises the following steps:

[0030] Step 1, obtain the temperature value T1 of the enclosed air around the inertial platform and the ambient temperature T2 of the inertial platform frame;

[0031] In this embodiment, before isolating the harmful temperature feedback, the temperature value of the enclosed air around the inertial platform in step 2 is T1≈40°C and the ambient temperature around the inertial platform frame is T2≈35°C;

[0032] Step 2: Rotate the inertial platform to obtain the maximum change dT2 of the ambient temperature T2 around the inertial platform frame;

[0033] In this embodiment, the maximum change of the ambient temperature T2 of the inertial platform frame in step 2 is dT2=2°C;

[0034] Step 3: Determine the damping target according to the temperature sensitivity of the inertial element and the accuracy of the inertial navigation system;

[0035] The specific method of step 3 is:

[0036] Determine the damping target (1-F)*(1 / dT2)*dT0 according to the temperature sensitivity of the inertial element and the accuracy of the inertial navigation system;

[0037] dT0 is the temperature control target fluctuation value.

[0038] In this embodiment, the target value F is 0.15 and dT0 is 0.2°C;

[0039] Step 4: Determine the target time t according to the actual rotation conditions;

[0040] In this embodiment, the target time t of step 4 is 60s;

[0041] Step 5: According to the first-order system response curve c(t)=1-e(-t / T), the damping link time constant T is calculated to determine the transfer function of the damping link;

[0042] In this embodiment, the block diagram of the temperature control system is as follows: Figure 1 As shown in the figure, Gc is the open-loop transfer function of PID control, and Gn uses the inertia link as the damping link;

[0043] In step 5, the transfer function of the damping link is Gn=K / (Ts+1), and the time constant of the damping link is calculated to be T=676s;

[0044] In this embodiment, K = 0.6;

[0045] Step 6: Design the damper and install it on the inertial platform frame.

[0046] The specific method of step 6 is:

[0047] In this embodiment, the designed damper is installed on the inertial platform frame.

[0048] In this embodiment, before isolation, T2 = (35 ± 1.0) ° C, T1 = (40 ± 0.6) ° C, and after isolation, T2 = (35 ± 1) ° C, T1 = (40 ± 0.1) ° C.

[0049] It should be emphasized that the embodiments of the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation modes. Any other implementation modes derived by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for determining the parameters of a damping link for isolating harmful temperature feedback, characterized in that: The following steps are involved: Step 1, obtain the temperature value T1 of the enclosed air around the inertial platform and the ambient temperature T2 of the inertial platform frame; Step 2: Rotate the inertial platform to obtain the maximum change dT2 of the ambient temperature T2 around the inertial platform frame; Step 3: Determine the damping target according to the temperature sensitivity of the inertial element and the accuracy of the inertial navigation system; Step 4: Determine the target time t according to the actual rotation conditions; Step 5: According to the first-order system response curve c(t)=1-e(-t / T), the damping link time constant T is calculated, thereby determining the transfer function of the damping link.

2. The method for determining the damping link parameters for isolating harmful temperature feedback according to claim 1, characterized in that: Before isolating harmful temperature feedback, the temperature value of the enclosed air around the inertial platform in step 1 is T1≈40°C and the ambient temperature around the inertial platform frame is T2≈35°C.

3. The method for determining the damping link parameters for isolating harmful temperature feedback according to claim 1, characterized in that: The maximum change dT2 of the ambient temperature T2 of the inertial platform frame in step 2 is 2°C.

4. The method for determining the damping link parameters for isolating harmful temperature feedback according to claim 1, characterized in that: The specific method of step 3 is: Determine the damping target based on the temperature sensitivity of the inertial element and the accuracy of the inertial navigation system (1-F)*(1 / dT2)*dT0; dT0 is the temperature control target fluctuation value.

5. The method for determining the damping link parameters for isolating harmful temperature feedback according to claim 1, characterized in that: The transfer function of the damping link in step 5 is Gn=K / (Ts+1), and the time constant of the damping link is calculated to be T=676s.

6. The method for determining the damping link parameters for isolating harmful temperature feedback according to claim 1, characterized in that: The step 5 further includes the following steps: Step 6: Design the damper and install it on the inertial platform frame.

Images