Stepping scanning imaging method based on trapezoidal acceleration and deceleration algorithm

Abstract

The invention belongs to the technical field of photoelectric search system control, and particularly relates to a stepped scanning imaging method based on a trapezoidal acceleration and deceleration algorithm, which comprises the following steps of: calculating a stepped scanning step length theta according to a current view field value of a photoelectric search system; a trapezoidal speed curve of the scanning step length theta is planned by adopting a trapezoidal acceleration and deceleration algorithm, so that acceleration and deceleration time t1 and constant speed time t2 corresponding to the highest speed omega SPE are obtained; controlling the rotary table of the photoelectric search system to move according to the speed curve planned in S120; outputting an exposure signal when reaching the specified position theta, and controlling the detector to start exposure; after the exposure is completed, returning to the step S130 to repeat the process until the panoramic imaging is completed; according to the step scanning imaging method based on the trapezoidal acceleration and deceleration algorithm, a designated position can be rapidly and stably reached, the imaging quality of the scanning process of a photoelectric search system is ensured, and in addition, the method is simple in design and easy to implement and has good engineering application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic search system control, and particularly relates to a stepped scanning imaging method based on a trapezoidal acceleration and deceleration algorithm. Background Art

[0002] In optoelectronic search system imaging technology, stepped scanning imaging is a widely used imaging technology for realizing 360° panoramic search and imaging of a target area. However, when traditional stepped scanning imaging controls the movement of the turntable of an optoelectronic search system, simple linear acceleration and deceleration or constant speed control strategies are mainly adopted, and these strategies have obvious deficiencies in fast and clear imaging. Specifically, although linear acceleration and deceleration control is simple to implement, during the acceleration and deceleration process, due to the too rapid speed change, it is easy to cause vibration and instability of the optoelectronic search system, thus affecting the imaging quality. Especially in the case of a large turntable inertia and limited motor capacity, this influence is particularly significant. On the other hand, although constant speed control can reduce vibration to a certain extent, in the case of searching for a distant target and a small imaging field of view, the constant speed search speed is too slow, resulting in a reduced imaging efficiency.

[0003] In summary, regarding the prior art, there is still a lack of an effective solution to improve the imaging efficiency of stepped scanning while ensuring the imaging quality. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] The technical problem to be solved by the present invention is: how to provide a stepped scanning imaging method based on a trapezoidal acceleration and deceleration algorithm to significantly improve the imaging efficiency in optoelectronic search while ensuring the stepped scanning imaging quality of an optoelectronic detection system, thereby solving the problems of excessive overshoot, oscillation, instability, and low imaging efficiency caused by traditional control strategies.

[0006] (2) Technical Solutions

[0007] To solve the above technical problems, the present invention provides a stepped scanning imaging method based on a trapezoidal acceleration and deceleration algorithm, and the method includes the following steps:

[0008] Step S110: Calculate the stepped scanning step size θ according to the current field of view value of the optoelectronic search system;

[0009] Step S120: Use the trapezoidal acceleration and deceleration algorithm to plan the trapezoidal speed curve of the scanning step size θ, so as to obtain the maximum speed ω SPE corresponding constant acceleration time t1, constant deceleration time t1, and constant speed time t2; wherein, the constant acceleration time is equal to the constant deceleration time;

[0010] Step S130: Control the turntable of the optoelectronic search system to move according to the trapezoidal velocity curve planned in step S120;

[0011] Step S140: Output an exposure signal when reaching the specified position, and control the detector to start exposure;

[0012] Step S150: After the exposure is completed, return to step S130 and repeat the above process until panoramic imaging is completed.

[0013] Among them, in the step S120, the trapezoidal acceleration and deceleration algorithm is a motion planning algorithm used to achieve a smooth acceleration and deceleration process for the purpose of stable motion; when using this algorithm for path planning, there is no need to care about the specific shape of the path, and the interpolation points on the path are calculated according to the geometric law and acceleration and deceleration law of the path.

[0014] Among them, the step size θ of the step-by-step scan in S110 is related to the current field of view value of the optoelectronic search system, and the calculation formula is as follows:

[0015] θ = FOV(1 - δ)

[0016] Among them, FOV is the current field of view value, and δ is the field of view angle overlap rate.

[0017] Among them, the trapezoidal velocity curve in S120 includes three stages: constant acceleration, constant velocity, and constant deceleration, involving the maximum velocity ω SPE , the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2, and the acceleration a and other parameters. The scan step size θ is calculated according to the geometric relationship of the trapezoidal velocity curve:

[0018] θ = ω SPE (t1 + t2).

[0019] Among them, the method of using the trapezoidal acceleration and deceleration algorithm in S120 to plan the trapezoidal velocity curve of the scan step size θ includes the following steps:

[0020] Step S210: In order to determine the trapezoidal velocity curve, specify some of the parameters, set the maximum acceleration a according to the servo system capacity of the turntable of the optoelectronic search system max , set the maximum angular velocity ω according to the control requirements max and the angular velocity step size ω s ;

[0021] Step S220: Let the intermediate angular velocity parameter ω0 = ω max , if holds, go to S250, otherwise let ω1 = ω0 and go to S230;

[0022] Step S230: Let ω0 = ω1 - ω s, if ω0 > 0 holds, go to S230; otherwise, go to S240;

[0023] Step S240: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = 0, the constant acceleration time and the constant deceleration time t1 = 0, and the constant velocity time t2 = 0;

[0024] Step S250: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = ω0, the constant acceleration time and the constant deceleration time the constant velocity time

[0025] Among them, the control system of the turntable of the optoelectronic search system in S130 is an inertial stabilization platform control system based on a gyroscope. By inputting a square wave signal, the turntable of the optoelectronic search system is made to move according to the planned trapezoidal velocity curve.

[0026] Among them, the exposure of the detector in S140 is controlled by an exposure signal, and the relationship between the detector exposure time t0 and the exposure signal time is:

[0027]

[0028] Among them, the amplitude ω A of the pulsed square wave signal is equal to the maximum velocity ω SPE , the pulse width t w is equal to the sum of the constant acceleration time t1 and the constant velocity time t2, and the period t p is equal to the sum of the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2 and the exposure signal time , that is:

[0029] ω A = ω SPE

[0030] t w = t1 + t2

[0031] t p = 2t1 + t2.

[0032] (III) Beneficial effects

[0033] Compared with the prior art, the step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm proposed by the present invention realizes a fast and stable imaging process by optimizing the control strategy of the turntable of the optoelectronic search system, effectively improves the imaging quality and efficiency, and the method design is simple and easy to be implemented in engineering. Description of the drawings

[0034] Figure 1It is a schematic diagram of the principle and steps of a step - scan imaging method based on the trapezoidal acceleration - deceleration algorithm;

[0035] Figure 2 It is a trapezoidal velocity curve graph;

[0036] Figure 3 It is an algorithm flowchart for planning the scanning step size using the trapezoidal acceleration - deceleration algorithm;

[0037] Figure 4 It is a control block diagram of an inertial stabilization platform control system based on a gyroscope;

[0038] Figure 5 It is a square - wave signal curve graph;

[0039] Figure 6 It is a control system speed input curve graph;

[0040] Figure 7 It is a control system position output curve graph. Detailed implementation manners

[0041] To make the objectives, content, and advantages of the present invention clearer, the following further describes the detailed implementation manners of the present invention in conjunction with the accompanying drawings and embodiments.

[0042] To solve the above - mentioned technical problems, the present invention provides a step - scan imaging method based on the trapezoidal acceleration - deceleration algorithm. The method includes the following steps:

[0043] Step S110: Calculate the step - scan step size θ according to the current field - of - view value of the optoelectronic search system;

[0044] Step S120: Use the trapezoidal acceleration - deceleration algorithm to plan the trapezoidal velocity curve of the scanning step size θ, so as to obtain the maximum speed ω SPE The corresponding constant - acceleration time t1, constant - deceleration time t1, and constant - velocity time t2; where the constant - acceleration time is equal to the constant - deceleration time;

[0045] Step S130: Control the turntable of the optoelectronic search system to move according to the trapezoidal velocity curve planned in step S120;

[0046] Step S140: Output an exposure signal when reaching the specified position, and control the detector to start exposure;

[0047] Step S150: After the exposure is completed, return to step S130 and repeat the above process until panoramic imaging is completed.

[0048] Among them, in the step S120, the trapezoidal acceleration and deceleration algorithm is a motion planning algorithm used to achieve a smooth acceleration and deceleration process for the purpose of stable motion. When using this algorithm for path planning, it is not necessary to care about the specific shape of the path. According to the geometric law and acceleration and deceleration law of the path, the interpolation points on the path are calculated.

[0049] Among them, the step size θ of the step-by-step scan in S110 is related to the current field of view value of the optoelectronic search system, and the calculation formula is as follows:

[0050] θ = FOV(1 - δ)

[0051] Among them, FOV is the current field of view value, and δ is the field of view angle overlap rate.

[0052] Among them, the trapezoidal velocity curve in S120 includes three stages: constant acceleration, constant velocity, and constant deceleration, involving parameters such as the maximum velocity ω SPE , the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2, and the acceleration a. The scan step size θ is calculated according to the geometric relationship of the trapezoidal velocity curve:

[0053] θ = ω SPE (t1 + t2).

[0054] Among them, the method of using the trapezoidal acceleration and deceleration algorithm to plan the trapezoidal velocity curve of the scan step size θ in S120 includes the following steps:

[0055] Step S210: To determine the trapezoidal velocity curve, specify some of the parameters, set the maximum acceleration a according to the capabilities of the turntable servo system of the optoelectronic search system max , set the maximum angular velocity ω according to the control requirements max and the angular velocity step size ω s ;

[0056] Step S220: Let the intermediate angular velocity parameter ω0 = ω max , if holds, go to S250, otherwise let ω1 = ω0 and go to S230;

[0057] Step S230: Let ω0 = ω1 - ω s , if ω0 > 0 holds, go to S230, otherwise go to S240;

[0058] Step S240: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = 0, the constant acceleration time and the constant deceleration time t1 = 0, the constant velocity time t2 = 0;

[0059] Step S250: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = ω0, the constant acceleration time and the constant deceleration time Constant velocity time

[0060] Among them, the control system of the turntable of the optoelectronic search system in S130 is an inertial stabilization platform control system based on gyroscopes. By inputting a square wave signal, the turntable of the optoelectronic search system is made to move according to the planned trapezoidal velocity curve.

[0061] Among them, the exposure of the detector in S140 is controlled by an exposure signal, and the relationship between the exposure time t0 of the detector and the exposure signal time is as follows:

[0062]

[0063] Among them, the amplitude ω A of the pulse square wave signal is equal to the maximum speed ω SPE , the pulse width t w is equal to the sum of the constant acceleration time t1 and the constant velocity time t2, and the period t p is equal to the sum of the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2 and the exposure signal time , that is:

[0064] ω A = ω SPE

[0065] t w = t1 + t2

[0066] t p = 2t1 + t2.

[0067] Embodiment 1

[0068] This embodiment provides a step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm. Its principle and steps are as Figure 1 shown, including the following steps:

[0069] S110: Calculate the step-scanning step size θ according to the current field of view value of the optoelectronic search system;

[0070] S120: Use the trapezoidal acceleration and deceleration algorithm to plan the trapezoidal velocity curve of the scanning step size θ, so as to obtain the control speed ω SPE the acceleration and deceleration time t1 and the constant velocity time t2;

[0071] S130: Control the turntable of the optoelectronic search system to move according to the velocity curve planned in S120;

[0072] S140: Output an exposure signal when reaching the specified position θ, and control the detector to start exposure;

[0073] S150: After the exposure is completed, return to S130 and repeat the above process until panoramic imaging is completed.

[0074] Among them, the trapezoidal acceleration and deceleration algorithm is a motion planning algorithm used to achieve a smooth acceleration and deceleration process for the purpose of stable motion. When using this algorithm for path planning, there is no need to care about the specific shape of the path. According to the geometric law and acceleration and deceleration law of the path, the interpolation points on the path are calculated.

[0075] The step size θ of the step-by-step scan in S110 is related to the current field of view value of the optoelectronic search system, and the calculation formula is as follows:

[0076] θ = FOV(1 - δ)

[0077] Among them, FOV is the current field of view value, and δ is the field of view angle overlap rate.

[0078] The trapezoidal velocity curve in S120 is as Figure 2 shown, including three stages of constant acceleration, constant velocity, and constant deceleration, involving the maximum velocity ω SPE , the constant acceleration time (and the constant deceleration time) t1, the constant velocity time t2, and the acceleration a parameters. According to the geometric relationship of the trapezoidal velocity curve, the scan step size θ can be calculated:

[0079] θ = ω SPE (t1 + t2)

[0080] The method of using the trapezoidal acceleration and deceleration algorithm to plan the scan step size θ of the trapezoidal velocity curve in S120 has the calculation process as Figure 3 shown, including the following steps:

[0081] S210: To determine the trapezoidal velocity curve, some of its parameters need to be specified. Set the maximum acceleration a according to the capabilities of the turntable servo system of the optoelectronic search system max , and set the maximum angular velocity ω max and the angular velocity step size ω s according to the control requirements;

[0082] S220: Let ω0 = ω max , if holds, go to S250, otherwise let ω1 = ω0 and go to S230;

[0083] S230: Let ω0 = ω1 - ω s , if ω0 > 0 holds, go to S220, otherwise go to S240;

[0084] S240: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = 0, the constant acceleration time (and the constant deceleration time) t1 = 0, and the constant velocity time t2 = 0;

[0085] S250: The trapezoidal velocity curve parameters are: the maximum velocity ω SPE = ω0, the constant acceleration time (and the constant deceleration time) the constant velocity time

[0086] The turntable control system of the optoelectronic search system in S130 is an inertial stabilization platform control system based on a gyroscope, and its control block diagram is as Figure 4 shown. By inputting a square wave signal, the turntable of the optoelectronic search system is made to move according to the planned trapezoidal velocity curve.

[0087] Among them, the amplitude ω of the pulse square wave signal A is equal to the maximum velocity ω SPE , and the pulse width t w is equal to the sum of the constant acceleration time t1 and the constant velocity time t2, and the period t p is equal to the sum of the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2 and the exposure signal time , that is:

[0088] ω A = ω SPE

[0089] t w = t1 + t2

[0090]

[0091] The exposure of the detector in S140 is controlled by the exposure signal, and the relationship between the detector exposure time t0 and the exposure signal time is:

[0092]

[0093] For the sake of easy understanding, taking the step-scanning working condition of an optoelectronic search system as an example, a step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm provided by the present invention is described in detail.

[0094] The current field of view value FOV of this system is 4°, and the field of view angle overlap rate is δ = 0.1. According to the step S110 described above, the step-scanning step θ is calculated as:

[0095] θ = FOV(1 - δ) = 4×(1 - 0.2) = 3.6°

[0096] According to the method of planning the trapezoidal velocity curve of the scanning step θ using the trapezoidal acceleration and deceleration algorithm in S120 described above, the trapezoidal velocity curve is planned, and the maximum acceleration a is set according to the capabilities of the turntable servo system of the optoelectronic search system max = 10rad / s2 , set the maximum angular velocity ω according to the control requirements max = 90° / s and the angular velocity step ω s = 5° / s; through the Figure 3 flow chart shown, calculate ω SPE = 45° / s,

[0097] As described above, the turntable control system of the optoelectronic search system in S130 is a gyro-based inertial stabilization platform control system, and its control block diagram is as shown in Figure 4 . By inputting a square wave signal, the turntable of the optoelectronic search system is made to move according to the planned trapezoidal velocity curve.

[0098] Among them, the pulse square wave signal is as shown in Figure 5 . Its amplitude ω A is equal to the highest speed ω SPE , the pulse width t w is equal to the sum of the constant acceleration time t1 and the constant velocity time t2, and the period t p is equal to the sum of the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2 and the exposure signal time . Among them, the exposure signal time of this system is 50 ms, that is:

[0099] ω A = ω SPE = 45° / s

[0100] t w = t1 + t2 = 80 ms

[0101]

[0102] In the matlab environment, build a mathematical model of the inertial stabilization platform of the turntable of the optoelectronic search system, and perform simulation by inputting the above square wave signal. Figure 6 is the speed input curve of this control system, Figure 7 is the position output curve of this control system. It can be seen from Figure 7 that by using the method proposed in the present invention, the turntable can quickly and smoothly reach the specified position, thereby improving the image quality of the detector exposure.

[0103] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A step-scanning imaging method based on a trapezoidal acceleration and deceleration algorithm, characterized in that, The method includes the following steps: Step S110: Calculate the step size θ of the step-by-step scan according to the current field of view value of the optoelectronic search system; Step S120: Plan the trapezoidal velocity curve of the scanning step θ using the trapezoidal acceleration and deceleration algorithm, so as to obtain the maximum velocity ω SPE The corresponding constant acceleration time t1, constant deceleration time t1, and uniform velocity time t2; among them, the constant acceleration time is equal to the constant deceleration time; Step S130: Control the turntable of the optoelectronic search system to move according to the trapezoidal velocity curve planned in step S120; Step S140: Output an exposure signal when reaching the specified position, and control the detector to start exposure; Step S150: After the exposure is completed, return to step S130 to repeat the above process until panoramic imaging is completed.

2. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 1, wherein, In the step S120, the trapezoidal acceleration and deceleration algorithm is a motion planning algorithm used to achieve a smooth acceleration and deceleration process for the purpose of stable motion; when using this algorithm for path planning, there is no need to care about the specific shape of the path, and the interpolation points on the path are calculated according to the geometric law and the acceleration and deceleration law of the path.

3. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 1, wherein, The step size θ of the step-by-step scan in the S110 is related to the current field of view value of the optoelectronic search system, and the calculation formula is as follows: θ = FOV(1 - δ) where FOV is the current field of view value and δ is the field of view angle overlap rate.

4. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 1, characterized in that, The trapezoidal velocity curve in S120 includes three stages: constant acceleration, constant velocity, and constant deceleration, and involves multiple parameters such as the maximum velocity ω SPE , the constant acceleration time t1, the constant deceleration time t1, the constant velocity time t2, and the acceleration a. The scanning step θ is calculated according to the geometric relationship of the trapezoidal velocity curve: θ = ω SPE (t1 + t2).

5. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 4, wherein The method for planning the trapezoidal velocity curve of the scan step size θ using the trapezoidal acceleration and deceleration algorithm in the S120 includes the following steps: Step S210: To determine the trapezoidal velocity curve, specify some of its parameters, set the maximum acceleration a according to the capabilities of the turntable servo system of the optoelectronic search system max , set the maximum angular velocity ω according to the control requirements max and the angular velocity step ω s ; Step S220: Let the angular velocity intermediate parameter ω0 = ω max , if holds, go to S250; otherwise, let ω1 = ω0 and go to S230; Step S230: Let ω0 = ω1 - ω s , if ω0 > 0 holds, go to S230, otherwise go to S240; Step S240: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = 0, the constant acceleration time and the constant deceleration time t1 = 0, and the constant velocity time t2 = 0; Step S250: The parameters of the trapezoidal velocity curve are: the maximum velocity ω SPE = ω0, the constant acceleration time, and the constant deceleration time the constant velocity time 6. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 5, characterized in that, The control system of the turntable of the optoelectronic search system in the S130 is an inertial stable platform control system based on a gyroscope. By inputting a square wave signal, the turntable of the optoelectronic search system is enabled to move according to the planned trapezoidal velocity curve.

7. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 6, wherein The exposure of the detector in S140 is controlled by an exposure signal, and the relationship between the detector exposure time t0 and the exposure signal time is as follows:

8. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 7, characterized in that The amplitude ω of the pulsed square wave signal A is equal to the maximum speed ω SPE , the pulse width t w is equal to the sum of the constant acceleration time t1 and the constant speed time t2, and the period t p is equal to the sum of the constant acceleration time t1, the constant deceleration time t1, the constant speed time t2 and the exposure signal time That is: ω A = ω SPE t w = t1 + t2 t p = 2t1 + t2.

9. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 8, wherein The method is used to significantly improve the imaging efficiency in optoelectronic search on the premise of ensuring the imaging quality of the step-by-step scan of the optoelectronic detection system.

10. The step-scanning imaging method based on the trapezoidal acceleration and deceleration algorithm according to claim 8, wherein, The method solves the problems of excessive overshoot, oscillation, instability, and low imaging efficiency caused by traditional control strategies.

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