CN103593818B - A kind of fast image processing method being applicable to soft landing process and space environment - Google Patents

Abstract

A fast image processing method suitable for soft landing process and space environment, suitable for the fast image processing requirements of space probe extraterrestrial celestial body landing process. The speed of image processing is accelerated by utilizing the cache resources in the DSP; at the same time, measures such as timer interruption and closing of the cache are taken to limit the working time of the cache to reduce the bad influence of the single event effect of the cache. The purpose of improving the processing speed while ensuring the adaptability of the space environment is achieved.

Description

A fast image processing method suitable for soft landing process and space environment

technical field

The invention relates to a fast image processing method suitable for the soft landing process and space environment, and is suitable for the fast image processing requirement of the space probe extraterrestrial celestial body landing process.

Background technique

During the soft landing process of the probe's extraterrestrial celestial body, if the landing safety point information can be obtained through active processing on-orbit, it will be very beneficial to improve the probability of landing safety. In the early landing missions such as the Apollo mission, human eyes were used to identify the safe point of landing. With the development of technology, relying on instruments and equipment to obtain accurate and safe landing point position information is a new requirement for landing missions, especially for unmanned landing probes. In order to complete the process of obtaining safe points independent of people, it is necessary to develop an image processing technology to quickly process the image information of the pre-landing area acquired during the landing process, such as optical images or laser elevation images or microwave elevation images. Faster processing speed saves landing fuel.

Image processing is generally performed by an image processing computer. Image Processing Computers take image acquisition devices (such as elevation maps or optical images) and process the image information of the landing zone to obtain safe landing site location information. The image processing computer provides the processing result to the control computer of the detector, and the control computer plans the target landing site according to the safe landing point information of the landing area obtained by the image processing.

Due to the short landing process time and the large amount of image information data, the processing algorithm is complex. Often requires a long image processing time. Generally speaking, there are two ways to improve the image processing speed, one is to optimize the algorithm, and the other is to improve the hardware processing capability. In the image processing equipment on the ground, cache (high-speed cache) is often used to improve the access speed of programs and data, so as to achieve the purpose of accelerating image processing speed. However, in space applications, the cache is prone to flipping under the action of space single particles, which will lead to errors in program flow or calculation results. Therefore, due to the single event effect in space, some functional modules (such as high-speed cache) of current high-performance processors often cannot be directly applied in the space environment, which limits the improvement of image processing speed during the landing process.

The low image processing speed will increase the time of the landing process, and the fuel consumption of the engine ignition will increase, which will increase the cost of the launch.

Contents of the invention

The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a fast image processing method suitable for the soft landing process and space environment, which can meet the rapidity requirements of image processing, and can also adapt to the space environment. The rapidity of image processing and landing safety point information is ensured, and the reliability is also ensured.

The technical scheme of the present invention is: a kind of fast image processing method that is applicable to soft landing process and space environment, and the steps are as follows:

1) The position information of the landing target point is preset in the detector control computer; the two image processing computers receive the landing images sent by the imaging sensor in parallel; the initial state settings of the two image processing computers are to use off-chip memory;

2) Two image processing computers simultaneously receive the image processing instruction sent by the detector control computer at time t0, and open the on-chip cache memory to process the landing image received in step 1); at the same time, set the timer to trigger at time t0+Δt Computer interruption; where Δt is the time required for image processing of the on-orbit landing zone obtained according to the ground test situation;

3) Both image processing computers receive timer interrupts at time t0+Δt, and close the on-chip cache memory;

4) Compare the image processing results of the two image processing computers; if the image processing results of the two image processing computers are consistent, use the image processing results to land and end; if the image processing results of the two image processing computers are inconsistent, Then enter step 5); the image processing result is the landing safety point position;

5) The detector control computer re-initiates image processing instructions to the two image processing computers, and repeats steps 2) to 4). If the image processing results of the two image processing computers are still inconsistent, use the preset value in step 1). The position information of the landing target point is used for landing.

The advantage of the present invention compared with prior art is:

1) Effectively improve the image processing speed. The typical value of the processing time of a single image is 7s before this method is not applied, and it is 2s after this method is adopted.

2) Ensure the reliability of the processing results. Because the control computer is used to compare the results of two image processing computers, it is ensured that abnormal results can be detected and eliminated.

Description of drawings

The flowchart of Fig. 1 fast image processing method;

Fig. 2 Topology diagram of device interface relationship.

detailed description

Below in conjunction with Fig. 1, Fig. 2, the method of the present invention will be further described.

1) The position information of the landing target point is preset in the detector control computer; the two image processing computers receive the landing images sent by the imaging sensor in parallel; the initial state settings of the two image processing computers are to use off-chip memory;

2) Two image processing computers simultaneously receive the image processing instruction sent by the detector control computer at time t0, and open the on-chip cache memory to process the landing image received in step 1); at the same time, set the timer to trigger at time t0+Δt Computer interruption; where Δt is the time required for image processing of the on-orbit landing zone obtained according to the ground test situation;

3) Both image processing computers receive timer interrupts at time t0+Δt, and close the on-chip cache memory;

4) Compare the image processing results of the two image processing computers; if the image processing results of the two image processing computers are consistent, use the image processing results to land and end; if the image processing results of the two image processing computers are inconsistent, Then enter step 5); the image processing result is the landing safety point position;

5) The detector control computer re-initiates image processing instructions to the two image processing computers, and repeats steps 2) to 4). If the image processing results of the two image processing computers are still inconsistent, use the preset value in step 1). The position information of the landing target point is used for landing.

Because according to the test results, since the image processing time is greatly shortened (from 7s to 2s) after using the cache, even if the secondary processing is performed, the time required is shorter than that without the cache. The spatial single event effect is a sporadic probability event. According to reference 1: SingleEventUpsetCharacterizationoftheSMJ320C6701DigitalSignalProcessorUsingProtonIrradiation, IEEERadiationEffectsDataWorkshop, July, 2005, p42-45, the probability of a single event upset within 2s can be obtained as 10 ^-6 . The chances of this happening in both image processing times are close to 0.

Parts not described in detail in the present invention belong to the common knowledge of those skilled in the art.

Claims (1)

1. be applicable to a fast image processing method for soft landing process and space environment, it is characterized in that step is as follows:

1) positional information of preset target point in detector computer for controlling; Two pattern process computers walk abreast reception by the landing chart picture becoming image sensor to send; The original state of two described pattern process computers arranges and is use chip external memory;

2) two pattern process computers are at the t0 moment process image command that send of pick-up probe computer for controlling simultaneously, and in opening sheet cache memory to step 1) the landing chart picture that receives processes; Arrange timer to interrupt at t0+ △ t trigger image process computer simultaneously; Wherein △ t is the time that the image procossing of touch-down zone in-orbit obtained according to ground test case needs;

3) two pattern process computers all receive timer interruption in t0+ △ t, and cache memory in Closure panel;

4) processing result image of two pattern process computers is compared; If the processing result image of two pattern process computers is consistent, then processing result image is adopted to carry out landing and terminating; If the processing result image of two pattern process computers is inconsistent, then enter step 5); Described processing result image is landing point of safes position;

5) detector computer for controlling initiates image processing commands again to two pattern process computers, and repeat step 2) ~ step 4), if the processing result image of two pattern process computers is still inconsistent, then adopt step 1) in the positional information of preset target point land.