阅读说明：本技术 一种用于指向机构的在线加减速控制方法、系统及介质 (Online acceleration and deceleration control method, system and medium for pointing mechanism ) 是由 江献良 范大鹏 张连超 范世珣 陈凌宇 黄征宇 于 2019-08-30 设计创作，主要内容包括：本发明公开了一种用于指向机构的在线加减速控制方法、系统及介质,本发明包括指令预处理、加减速判断和有限行程处理三个部分,指令预处理指获取目标运动状态和当前运动状态等信息；加减速判断是根据跟随误差最小和时间最优的原则判断加减速策略；有限行程处理用于实现限位保护和防止碰撞功能；根据最终的加减速策略确定下一时刻的位置、速度和加速度状态,从而实现指向机构的在线加减速规划。本发明完全考虑了加速度、速度和位置的任意边界,适用于任意的起始和目标运动状态,有助于指向机构响应连续变化的指令,在保证伺服运动准确性的同时,提升运动过程的平稳性。(The invention discloses an online acceleration and deceleration control method, a system and a medium for a pointing mechanism, wherein the online acceleration and deceleration control method comprises three parts of instruction preprocessing, acceleration and deceleration judgment and limited travel processing, wherein the instruction preprocessing refers to the acquisition of information such as a target motion state, a current motion state and the like; the acceleration and deceleration judgment is to judge an acceleration and deceleration strategy according to the principle of minimum following error and optimal time; the limited stroke processing is used for realizing the functions of limiting protection and preventing collision; and determining the position, the speed and the acceleration state at the next moment according to the final acceleration and deceleration strategy, thereby realizing the online acceleration and deceleration planning of the pointing mechanism. The invention completely considers any boundary of acceleration, speed and position, is suitable for any initial and target motion state, is beneficial to the response of a pointing mechanism to continuously changing instructions, and improves the stability of the motion process while ensuring the accuracy of servo motion.)

1. An online acceleration and deceleration control method for a pointing mechanism is characterized by comprising the following implementation steps:

1) determining a current system state of the pointing mechanism;

2) determining an estimated acceleration-deceleration state value for a next servo cycle based on a current state of the system

3) Judging whether limited travel limit exists or not, if so, determining a safety position boundary sres under the limited travel condition, and correcting the estimated acceleration and deceleration state value of the next servo period according to the safety position boundary sres to obtain the acceleration an +1 of the next servo period; otherwise, directly taking the estimated acceleration and deceleration state value of the next servo period as the acceleration an +1 of the next servo period;

4) the position sn +1 and velocity vn +1 of the next servo cycle are calculated from the acceleration an +1 of the next servo cycle.

2. The on-line acceleration and deceleration control method for the pointing mechanism according to claim 1, wherein the detailed steps of step 1) include: acquiring a current position s0 and a current speed v0 as starting point states of the online motion planning; obtaining a target speed vt by carrying out differential calculation on the target position according to the target position st; and acquiring the rated speed vmax and the rated torque Tm of a servo motor of the pointing mechanism, and calculating the inertia Jm, the equivalent friction force Tf and the maximum acceleration amax of a motion shafting of the pointing mechanism.

3. The on-line acceleration/deceleration control method for a pointing mechanism according to claim 2, wherein a calculation function expression of the maximum acceleration amax is as shown in formula (1);

In the formula (1), Tm is a rated torque, Tf is an equivalent friction force, and Jm is inertia of a motion shafting of the pointing mechanism.

4. the on-line acceleration/deceleration control method for a pointing device according to claim 1, wherein the step 2) of determining the estimated acceleration/deceleration state value of the next servo cycle based on the current system state specifically uses a decision tree-based acceleration/deceleration determination method to determine the estimated acceleration/deceleration state value of the next servo cycle, and the step of determining the estimated acceleration/deceleration state value of the next servo cycle using the decision tree-based acceleration/deceleration determination method comprises:

2.1) determining the state of the decision tree based on the current position s0 and the current velocity v0 and the target velocity vt: if s0 < st, v0 > 0, and vt > 0, then the decision tree state is state 1; if s0 is less than st, v0 is more than 0 and vt is less than or equal to 0, the decision tree state is state 2; if s0 is less than st, v0 is less than or equal to 0 and vt is more than or equal to 0, the decision tree state is state 3; if s0 is less than st, v0 is less than or equal to 0 and vt is less than or equal to 0, the decision tree state is state 4; if s0 is greater than st, v0 is greater than or equal to 0 and vt is greater than or equal to 0, the decision tree state is state 5; if s0 is greater than st, v0 is greater than or equal to 0 and vt is less than 0, the decision tree state is state 6; if s0 is greater than st, v0 is less than 0 and vt is greater than or equal to 0, the decision tree state is state 7; if s0 > st, v0 < 0, and vt < 0, then the decision tree state is state 8;

2.2) jumping to execute the step 2.3 when the decision tree state is the state 1 or the state 8); skipping to execute step 2.4 when the decision tree state is state 2 or state 7); skipping to execute the step 2.5 when the decision tree state is 3-6);

2.3) judging whether the absolute value of the current velocity v0 is less than or equal to the absolute value of the target velocity vt, if so, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (2), otherwise, judging whether the formula (3) is true, if so, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (4), otherwise, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (5), and skipping and executing the step 3);

abs((v+2×a×T)-v)/2/a≥abs(s-s) (3)

in the formulas (2) to (5), s0 is the current position, st is the target position, amax is the maximum acceleration of the motion shafting of the pointing mechanism, v0 is the current speed, vt is the target speed, and T is the servo period;

2.4) judging whether the expression (6) is established, if so, determining the estimated acceleration and deceleration state value of the next servo period based on the expression (7), otherwise, determining the estimated acceleration and deceleration state value of the next servo period based on the expression (8) and skipping to execute the step 3);

abs((v+2×a×T)-v)/2/a≥abs(s-s) (6)

in the formulas (6) to (8), s0 is the current position, st is the target position, amax is the maximum acceleration of the motion shafting of the pointing mechanism, v0 is the current speed, vt is the target speed, and T is the servo period;

2.5) determining the estimated acceleration and deceleration state value of the next servo period based on the formula (9) to jump and execute the step 3);

In equation (9), s0 represents the current position, st represents the target position, and amax represents the maximum acceleration of the motion axis of the pointing mechanism.

5. The online acceleration/deceleration control method for a pointing mechanism according to claim 1, wherein the step 3) of correcting the estimated acceleration/deceleration state value of the next servo cycle according to the safe position boundary sres is to determine whether equation (10) is satisfied, and if so, determine the acceleration an +1 of the next servo cycle based on equation (11), otherwise, determine the acceleration an +1 of the next servo cycle based on equation (12); skipping to execute the step 3);

(v+2×a×T)/2/a≥abs(s-s) (10)

a＝-sign(s-s)×a (11)

in equations (10) to (12), v0 is the current velocity, amax is the maximum acceleration of the motion axis of the pointing mechanism, T is the servo period, s0 is the current position, st is the target position, sres is the safe position boundary, which is the estimated acceleration/deceleration state value of the next servo period, and sign is the sign function.

6. The on-line acceleration/deceleration control method for a pointing mechanism according to claim 1, wherein the step of calculating the velocity vn +1 of the next servo cycle from the acceleration an +1 of the next servo cycle in step 4) comprises: calculating the speed vn +1 of the next servo period according to the formula (13), judging whether the speed vn +1 of the next servo period is greater than the rated speed vmax of the servo motor, and if so, taking the rated speed of the servo motor as the speed vn +1 of the next servo period;

v＝v+aT (13)

in equation (13), v0 represents the current velocity, an +1 represents the acceleration in the next servo cycle, and T represents the servo cycle.

7. the on-line acceleration/deceleration control method for a pointing mechanism according to claim 1, wherein the functional expression of the position sn +1 of the next servo cycle calculated in step 4) from the acceleration an +1 of the next servo cycle is represented by equation (14);

s＝vT+aT/2 (14)

in equation (13), v0 represents the current velocity, an +1 represents the acceleration in the next servo cycle, and T represents the servo cycle.

8. an online acceleration/deceleration control system for a pointing mechanism, characterized by comprising:

a current state detection program unit for determining the current state of the system of the pointing mechanism;

An acceleration/deceleration state estimation program unit for determining the estimated acceleration/deceleration state value of the next servo cycle based on the current state of the system

The acceleration and deceleration state correction program unit is used for judging whether limited travel limit exists or not, determining a safe position boundary sres under the limited travel condition if the limited travel exists, and correcting the estimated acceleration and deceleration state value of the next servo period according to the safe position boundary sres to obtain the acceleration an +1 of the next servo period; otherwise, directly taking the estimated acceleration and deceleration state value of the next servo period as the acceleration an +1 of the next servo period;

and the position and speed calculation program unit is used for calculating the position sn +1 and the speed vn +1 of the next servo period according to the acceleration an +1 of the next servo period.

9. An online acceleration and deceleration control system for a pointing mechanism, comprising a computer device, characterized in that the computer device is programmed or configured to execute the steps of the online acceleration and deceleration control method for a pointing mechanism according to any one of claims 1 to 7, or a computer program programmed or configured on a storage medium of the computer device to execute the online acceleration and deceleration control method for a pointing mechanism according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium is programmed or configured with a computer program for executing the method for online acceleration/deceleration control of a pointing mechanism according to any one of claims 1 to 7.

Technical Field

the invention relates to a pointing mechanism motion control and online motion planning control technology, in particular to an online acceleration and deceleration control method, system and medium for a pointing mechanism.

Background

the pointing mechanism is a key component of the photoelectric sight stabilizing system, realizes the space pointing accuracy of a visual axis and a sight line through high-accuracy dynamic response performance, and is widely applied to the fields of airborne photoelectric pods, vehicle-mounted photoelectric masts, surface naval vessels and aerospace. The pointing mechanism acquires the space pointing deviation of a visual axis and an aiming line by means of a sensing device such as an image tracker and the like, the deviation is input into a servo system as an instruction, and the pointing deviation is eliminated through the dynamic adjustment of the servo system, so that the target is tracked.

For a pointing mechanism, the bandwidth of a servo system is an important index of dynamic response performance and represents the rapidity of the servo system for responding to instructions, but the bandwidth of the servo system is limited by nonlinear factors such as actuator power saturation and current saturation, and a servo controller can be more easily designed into a high-bandwidth servo loop by performing online acceleration and deceleration planning on the instructions under the condition of ensuring the accuracy of the instructions, so that the dynamic response capability of the system is improved.

the acceleration and deceleration control is a key technology in the field of motion control, common acceleration and deceleration methods comprise linear acceleration and deceleration, trigonometric function acceleration and deceleration, exponential acceleration and deceleration, S-curve acceleration and deceleration and the like, and are mainly used for carrying out uniform acceleration or uniform acceleration planning on a large-stroke command and avoiding vibration and noise phenomena caused by the motion process of a system, the photoelectric tracking process of the pointing mechanism has high requirement on the real-time performance of command response, the conventional static motion planning method has long calculation period, only aims at the condition that the initial speed and the final speed have the same sign, and is not suitable for the condition that a target command is continuously changed and randomly changed in the tracking process.

The online acceleration and deceleration control method comprehensively considers the dynamic characteristics and the servo performance of the pointing mechanism, has the characteristic that the motion planning period is equal to the servo period, can respond to continuously-changed target instructions, and is more suitable for the tracking process of the pointing mechanism.

the Chinese patent document with the application number of 201810844507.3 and the name of 'S curve acceleration and deceleration planning method at any displacement speed based on trapezoidal solution' discloses an S curve acceleration and deceleration planning method at any position and speed based on trapezoidal solution, and provides a processing method for performing acceleration and deceleration planning at any position and speed without zero points aiming at the problem that the conventional S curve method can only plan speed and time in sections and has low efficiency, so that the problem that the movement planning under the condition that the position and the initial and final speeds are negative values is solved, but target instructions which change continuously cannot be responded. The Chinese patent document with the application number of 201610116683.6 and the name of 'S-shaped acceleration and deceleration control method for changing the target speed and position on line' discloses an S-shaped acceleration and deceleration control method for changing the target speed and position on line, which mainly carries out speed planning of an acceleration section, a deceleration section and a constant speed section, adopts a discretization speed planning method, corrects the planned speed according to the criterion whether the maximum acceleration and the maximum speed can be reached, and allows the target speed and position to be changed for many times. The chinese patent document with the application number of 201910097753.1 and the name of "a multi-axis time synchronization method in S-type acceleration and deceleration trajectory planning" discloses a motion planning that can be used for the situation where the acceleration is equal to zero under the constraint condition of motion, different initial states and end states, and can realize time synchronization trajectory planning for multiple axes, and is suitable for generating trajectories on line in real time, and can make a robot quickly respond to unknown objects in the motion state, but in the situation where the acceleration is close to zero, the acceleration continuous constraint causes the speed change slowly, and in the situation where the target command continuously changes, the real-time generation trajectory affects the calculation efficiency.

disclosure of Invention

The technical problems to be solved by the invention are as follows: the invention is suitable for the target tracking process of the pointing mechanism, can respond to real-time changing target instructions, has the characteristics of high calculation speed and high precision, and lays a foundation for improving the servo dynamic performance of the pointing mechanism by preprocessing the target instructions.

In order to solve the technical problems, the invention adopts the technical scheme that:

An online acceleration and deceleration control method for a pointing mechanism comprises the implementation steps of:

1) determining a current system state of the pointing mechanism;

2) determining an estimated acceleration-deceleration state value for a next servo cycle based on a current state of the system

3) Judging whether limited travel limit exists or not, if so, determining a safety position boundary sres under the limited travel condition, and correcting the estimated acceleration and deceleration state value of the next servo period according to the safety position boundary sres to obtain the acceleration an +1 of the next servo period; otherwise, directly taking the estimated acceleration and deceleration state value of the next servo period as the acceleration an +1 of the next servo period;

4) the position sn +1 and velocity vn +1 of the next servo cycle are calculated from the acceleration an +1 of the next servo cycle.

optionally, the detailed steps of step 1) include: acquiring a current position s0 and a current speed v0 as starting point states of the online motion planning; obtaining a target speed vt by carrying out differential calculation on the target position according to the target position st; and acquiring the rated speed vmax and the rated torque Tm of a servo motor of the pointing mechanism, and calculating the inertia Jm, the equivalent friction force Tf and the maximum acceleration amax of a motion shafting of the pointing mechanism.

Optionally, a calculation function expression of the maximum acceleration amax is shown as formula (1);

in the formula (1), Tm is a rated torque, Tf is an equivalent friction force, and Jm is inertia of a motion shafting of the pointing mechanism.

Optionally, the step 2) of determining the estimated acceleration/deceleration state value of the next servo cycle based on the current state of the system, specifically, determining the estimated acceleration/deceleration state value of the next servo cycle by using an acceleration/deceleration judging method based on a decision tree, where the step of determining the estimated acceleration/deceleration state value of the next servo cycle by using the acceleration/deceleration judging method based on the decision tree includes:

2.1) determining the state of the decision tree based on the current position s0 and the current velocity v0 and the target velocity vt: if s0 < st, v0 > 0, and vt > 0, then the decision tree state is state 1; if s0 is less than st, v0 is more than 0 and vt is less than or equal to 0, the decision tree state is state 2; if s0 is less than st, v0 is less than or equal to 0 and vt is more than or equal to 0, the decision tree state is state 3; if s0 is less than st, v0 is less than or equal to 0 and vt is less than or equal to 0, the decision tree state is state 4; if s0 is greater than st, v0 is greater than or equal to 0 and vt is greater than or equal to 0, the decision tree state is state 5; if s0 is greater than st, v0 is greater than or equal to 0 and vt is less than 0, the decision tree state is state 6; if s0 is greater than st, v0 is less than 0 and vt is greater than or equal to 0, the decision tree state is state 7; if s0 > st, v0 < 0, and vt < 0, then the decision tree state is state 8;

2.2) jumping to execute the step 2.3 when the decision tree state is the state 1 or the state 8); skipping to execute step 2.4 when the decision tree state is state 2 or state 7); skipping to execute the step 2.5 when the decision tree state is 3-6);

2.3) judging whether the absolute value of the current velocity v0 is less than or equal to the absolute value of the target velocity vt, if so, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (2), otherwise, judging whether the formula (3) is true, if so, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (4), otherwise, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (5), and skipping and executing the step 3);

abs((v+2×a×T)-v)/2/a≥abs(s-s) (3)

In the formulas (2) to (5), s0 is the current position, st is the target position, amax is the maximum acceleration of the motion shafting of the pointing mechanism, v0 is the current speed, vt is the target speed, and T is the servo period;

2.4) judging whether the expression (6) is established, if so, determining the estimated acceleration and deceleration state value of the next servo period based on the expression (7), otherwise, determining the estimated acceleration and deceleration state value of the next servo period based on the expression (8) and skipping to execute the step 3);

abs((v+2×a×T)-v)/2/a≥abs(s-s) (6)

in the formulas (6) to (8), s0 is the current position, st is the target position, amax is the maximum acceleration of the motion shafting of the pointing mechanism, v0 is the current speed, vt is the target speed, and T is the servo period;

2.5) determining the estimated acceleration and deceleration state value of the next servo period based on the formula (9) to jump and execute the step 3);

in equation (9), s0 represents the current position, st represents the target position, and amax represents the maximum acceleration of the motion axis of the pointing mechanism.

Optionally, the step 3) of correcting the estimated acceleration/deceleration state value of the next servo cycle according to the safety position boundary sres specifically includes determining whether equation (10) is satisfied, if so, determining acceleration an +1 of the next servo cycle based on equation (11), otherwise, determining acceleration an +1 of the next servo cycle based on equation (12); skipping to execute the step 3);

(v+2×a×T)/2/a≥abs(s-s) (10)

a＝-sign(s-s)×a (11)

In equations (10) to (12), v0 is the current velocity, amax is the maximum acceleration of the motion axis of the pointing mechanism, T is the servo period, s0 is the current position, st is the target position, sres is the safe position boundary, which is the estimated acceleration/deceleration state value of the next servo period, and sign is the sign function.

optionally, the step of calculating the velocity vn +1 of the next servo cycle according to the acceleration an +1 of the next servo cycle in step 4) includes: calculating the speed vn +1 of the next servo period according to the formula (13), judging whether the speed vn +1 of the next servo period is greater than the rated speed vmax of the servo motor, and if so, taking the rated speed of the servo motor as the speed vn +1 of the next servo period;

v＝v+aT (13)

In equation (13), v0 represents the current velocity, an +1 represents the acceleration in the next servo cycle, and T represents the servo cycle.

Optionally, in the step 4), calculating a functional expression of the position sn +1 of the next servo period according to the acceleration an +1 of the next servo period as shown in the formula (14);

s＝vT+aT/2 (14)

In equation (13), v0 represents the current velocity, an +1 represents the acceleration in the next servo cycle, and T represents the servo cycle.

in addition, the present invention also provides an online acceleration and deceleration control system for a pointing mechanism, comprising:

A current state detection program unit for determining the current state of the system of the pointing mechanism;

an acceleration/deceleration state estimation program unit for determining the estimated acceleration/deceleration state value of the next servo cycle based on the current state of the system

The acceleration and deceleration state correction program unit is used for judging whether limited travel limit exists or not, determining a safe position boundary sres under the limited travel condition if the limited travel exists, and correcting the estimated acceleration and deceleration state value of the next servo period according to the safe position boundary sres to obtain the acceleration an +1 of the next servo period; otherwise, directly taking the estimated acceleration and deceleration state value of the next servo period as the acceleration an +1 of the next servo period;

and the position and speed calculation program unit is used for calculating the position sn +1 and the speed vn +1 of the next servo period according to the acceleration an +1 of the next servo period.

furthermore, the present invention also provides an online acceleration/deceleration control system for a pointing mechanism, comprising a computer device programmed or configured to execute the steps of the online acceleration/deceleration control method for a pointing mechanism, or a computer program programmed or configured on a storage medium of the computer device to execute the online acceleration/deceleration control method for a pointing mechanism.

Furthermore, the present invention also provides a computer-readable storage medium having a computer program programmed or configured thereon to execute the online acceleration/deceleration control method for a pointing mechanism.

Compared with the prior art, the invention has the following advantages: the invention determines the estimated acceleration and deceleration state value of the next servo period based on the current state of the system (for example, by comparing the states of the target position, the speed, the current position, the speed and the like, and judging the acceleration and deceleration strategy of the next servo period based on the principle of minimum following error and optimal time), the factors of limit protection and collision prevention are comprehensively considered, the safe position boundary is adopted to correct the acceleration and deceleration strategy, therefore, the invention completely considers the current state (acceleration, speed, position and the like) and the safe position boundary of the system, is suitable for any initial and target motion states, keeps the period of the motion planning consistent with the servo control period, is beneficial to the flexible response of the pointing mechanism to continuously changing instructions, the method has the advantages that the servo motion accuracy is guaranteed, meanwhile, the stability of the motion process is improved, and a foundation is laid for improving the dynamic response performance of a servo control system through the preprocessing of the target instruction.

Drawings

FIG. 1 is a schematic diagram of a basic flow of a method according to an embodiment of the present invention.

FIG. 2 is a detailed flow chart of the method according to the embodiment of the present invention.

FIG. 3 is a schematic diagram of the target azimuth direction coordinate changing with time in the embodiment of the present invention.

FIG. 4 is a diagram of target instructions and plans from 0s to 0.02s according to an embodiment of the present invention.

Fig. 5 is a diagram of an online motion planning trajectory for a sinusoidal motion object in an embodiment of the present invention.

Detailed Description

the online acceleration and deceleration control method, system and medium for a pointing mechanism according to the present invention will be further described in detail below, taking a certain type of pointing mechanism as an example. The pointing mechanism has the tracking capability of two degrees of freedom of azimuth and pitching, the product function requires the visual axis of the pointing mechanism to point to the target in real time, and in order to simplify the example, only the tracking function of the azimuth axis is explained in detail in the following specific implementation mode.

as shown in fig. 1, the implementation steps of the online acceleration and deceleration control method for the pointing mechanism in this embodiment include:

1) Determining a current system state of the pointing mechanism;

2) Determining an estimated acceleration-deceleration state value for a next servo cycle based on a current state of the system

3) Judging whether limited travel limit exists or not, if so, determining a safety position boundary sres under the limited travel condition, and correcting the estimated acceleration and deceleration state value of the next servo period according to the safety position boundary sres to obtain the acceleration an +1 of the next servo period; otherwise, directly taking the estimated acceleration and deceleration state value of the next servo period as the acceleration an +1 of the next servo period;

4) The position sn +1 and velocity vn +1 of the next servo cycle are calculated from the acceleration an +1 of the next servo cycle.

Referring to fig. 2, the detailed steps of step 1) of the present embodiment include: acquiring a current position s0 and a current speed v0 as starting point states of the online motion planning; obtaining a target speed vt by carrying out differential calculation on the target position according to the target position st; and acquiring the rated speed vmax and the rated torque Tm of a servo motor of the pointing mechanism, and calculating the inertia Jm, the equivalent friction force Tf and the maximum acceleration amax of a motion shafting of the pointing mechanism.

In the embodiment, the expression of the calculation function of the maximum acceleration amax is shown as the formula (1);

In the formula (1), Tm is a rated torque, Tf is an equivalent friction force, and Jm is inertia of a motion shafting of the pointing mechanism.

in the embodiment, at the time of 0.00ms, the initial pointing coordinate is (0,0) °, the target enters the sight range, the coordinate is located at (0,0.5) °andis performing sine motion of sin (2 pi × 0.5t) °, fig. 3 is a schematic diagram of the change of the coordinate in the direction of the target azimuth along with time, the task is set that the pointing mechanism starts from the initial position and continuously approaches to a target motion curve, and the motion planning is performed on-line motion planning based on a linear acceleration and deceleration principle, so that the tracking process is stable, and the maximum tracking capability of the pointing mechanism is reflected. Looking up a product manual of a servo motor and a speed reducer of the pointing mechanism, the equivalent maximum speed vmax of the azimuth axis of the pointing mechanism is 65 degrees/s, and the rated torque Tm is 70 N.m. And calculating the inertia Jm of the motion shafting of the pointing mechanism to be 0.2kg.m2 and the equivalent friction Tm to be 20N.m, and calculating the maximum acceleration amax to be 250m/s2 according to the Lagrange equation. At time 0.00s, target position st is 0.5 °, target speed vt is pi °/s2, current position s0 is 0 °, and current speed v0 is 0 °/s 2.

In this embodiment, step 2) determines the estimated acceleration/deceleration state value of the next servo cycle based on the current state of the system, specifically, determines the estimated acceleration/deceleration state value of the next servo cycle by using a decision tree-based acceleration/deceleration determination method

referring to fig. 2, the step of determining the estimated acceleration/deceleration state value of the next servo cycle by using the acceleration/deceleration determination method based on the decision tree in this embodiment includes:

2.1) determining the state of the decision tree based on the current position s0 and the current velocity v0 and the target velocity vt: if s0 < st, v0 > 0, and vt > 0, then the decision tree state is state 1; if s0 is less than st, v0 is more than 0 and vt is less than or equal to 0, the decision tree state is state 2; if s0 is less than st, v0 is less than or equal to 0 and vt is more than or equal to 0, the decision tree state is state 3; if s0 is less than st, v0 is less than or equal to 0 and vt is less than or equal to 0, the decision tree state is state 4; if s0 is greater than st, v0 is greater than or equal to 0 and vt is greater than or equal to 0, the decision tree state is state 5; if s0 is greater than st, v0 is greater than or equal to 0 and vt is less than 0, the decision tree state is state 6; if s0 is greater than st, v0 is less than 0 and vt is greater than or equal to 0, the decision tree state is state 7; if s0 > st, v0 < 0, and vt < 0, then the decision tree state is state 8;

2.2) jumping to execute the step 2.3 when the decision tree state is the state 1 or the state 8); skipping to execute step 2.4 when the decision tree state is state 2 or state 7); skipping to execute the step 2.5 when the decision tree state is 3-6);

2.3) judging whether the absolute value of the current velocity v0 is less than or equal to the absolute value of the target velocity vt, if so, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (2), otherwise, judging whether the formula (3) is true, if so, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (4), otherwise, determining the estimated acceleration and deceleration state value of the next servo cycle based on the formula (5), and skipping and executing the step 3);

abs((v+2×a×T)-v)/2/a≥abs(s-s) (3)

in the formulas (2) to (5), s0 is the current position, st is the target position, amax is the maximum acceleration of the motion shafting of the pointing mechanism, v0 is the current speed, vt is the target speed, and T is the servo period;

2.4) judging whether the expression (6) is established, if so, determining the estimated acceleration and deceleration state value of the next servo period based on the expression (7), otherwise, determining the estimated acceleration and deceleration state value of the next servo period based on the expression (8) and skipping to execute the step 3);

abs((v+2×a×T)-v)/2/a≥abs(s-s) (6)

in the formulas (6) to (8), s0 is the current position, st is the target position, amax is the maximum acceleration of the motion shafting of the pointing mechanism, v0 is the current speed, vt is the target speed, and T is the servo period;

2.5) determining the estimated acceleration and deceleration state value of the next servo period based on the formula (9) to jump and execute the step 3);

In equation (9), s0 represents the current position, st represents the target position, and amax represents the maximum acceleration of the motion axis of the pointing mechanism.

as can be seen from the foregoing, the current position s0, the current speed v0 and the target speed vt of the present embodiment satisfy:

st is more than s0, v0 is less than or equal to 0, and vt is more than or equal to 0

therefore, if the decision tree state is state 3, the estimated acceleration/deceleration state value of the next servo cycle is determined based on equation (9) at time 0.00s

Referring to fig. 2, the step 3) of the present embodiment of correcting the estimated acceleration/deceleration state value of the next servo cycle according to the safe position boundary sres specifically means determining whether equation (10) is satisfied, if so, determining an acceleration an +1 of the next servo cycle based on equation (11), otherwise, determining the acceleration an +1 of the next servo cycle based on equation (12); skipping to execute the step 3);

(v+2×a×T)/2/a≥abs(s-s) (10)

a＝-sign(s-s)×a (11)

in equations (10) to (12), v0 is the current velocity, amax is the maximum acceleration of the motion axis of the pointing mechanism, T is the servo period, s0 is the current position, st is the target position, sres is the safe position boundary, which is the estimated acceleration/deceleration state value of the next servo period, and sign is the sign function.

in step 3) of this embodiment, if it is determined that the azimuth axis system can perform turnaround and there is no limited stroke limit, then limited stroke processing is not required, so that the acceleration an +1 of the next servo cycle is determined based on equation (12):

Referring to fig. 2, the step of calculating the velocity vn +1 of the next servo cycle according to the acceleration an +1 of the next servo cycle in step 4) of the present embodiment includes: calculating the speed vn +1 of the next servo period according to the formula (13), judging whether the speed vn +1 of the next servo period is greater than the rated speed vmax of the servo motor, and if so, taking the rated speed of the servo motor as the speed vn +1 of the next servo period;

v＝v+aT (13)

In equation (13), v0 represents the current velocity, an +1 represents the acceleration in the next servo cycle, and T represents the servo cycle.

Referring to fig. 2, in step 4) of this embodiment, a functional expression of the position sn +1 of the next servo cycle is calculated according to the acceleration an +1 of the next servo cycle, as shown in formula (14);

s＝vT+aT/2 (14)

in equation (13), v0 represents the current velocity, an +1 represents the acceleration in the next servo cycle, and T represents the servo cycle.

The position and velocity of the next servo cycle obtained in step 4) of this embodiment can be calculated: v 1-v 0+ a 1T-0.5 °/s, and if the maximum speed is not exceeded, the displacement is s 1-v 0T + a1T 2/2-0.00025 °. Fig. 4 shows the target position command, the planned position command and the planned acceleration value from time 0 to 0.02s, it being seen that at time 0.00s the planned position and the planned velocity are the calculated values.

in this embodiment, the decision tree is used to calculate that the states of the decision tree are all states 3 from 0.00s to 0.02s, and as can be seen from fig. 3, the on-line planned command accelerations are amax, the acceleration is amax constantly, and the planned position command approaches the target position command by the maximum acceleration capability of the pointing mechanism.

Fig. 5 is an online motion planning trajectory diagram of the pointing mechanism for a sinusoidal motion target, and it can be seen that, at the time of 0 to 0.1s, the online motion planning trajectory can approach the target motion trajectory according to the acceleration capability of the servo system, and after 0.1s, although the target trajectory is continuously changed, the online motion planning trajectory can continuously follow and approach the target position, and meanwhile, the instruction jump phenomenon is not generated, and the influence of nonlinear links such as power saturation on the servo performance is prevented.

pointing accuracy is an important embodiment of the servo performance of the pointing mechanism, but the improvement of the servo performance is limited by nonlinear factors such as power saturation, and the like. The online acceleration and deceleration control method for the pointing mechanism mainly comprises three parts, namely instruction preprocessing (step 1), acceleration and deceleration judgment (step 2) and limited travel processing (step 3), wherein the instruction preprocessing refers to acquiring information such as a target motion state and a current motion state; the acceleration and deceleration judgment is to judge an acceleration and deceleration strategy according to the principle of minimum following error and optimal time; the limited stroke processing is used for realizing the functions of limiting protection and preventing collision; and determining the position, the speed and the acceleration state at the next moment according to the final acceleration and deceleration strategy, thereby realizing the online acceleration and deceleration planning of the pointing mechanism. The online acceleration and deceleration control method for the pointing mechanism completely considers any boundary of acceleration, speed and position, is suitable for any initial and target motion states, is beneficial to the pointing mechanism to respond to continuously changing instructions, and improves the stability of the motion process while ensuring the accuracy of servo motion.

in addition, the present embodiment further provides an online acceleration and deceleration control system for a pointing mechanism, including:

a current state detection program unit for determining the current state of the system of the pointing mechanism;

an acceleration/deceleration state estimation program unit for determining the estimated acceleration/deceleration state value of the next servo cycle based on the current state of the system

the acceleration and deceleration state correction program unit is used for judging whether limited travel limit exists or not, determining a safe position boundary sres under the limited travel condition if the limited travel exists, and correcting the estimated acceleration and deceleration state value of the next servo period according to the safe position boundary sres to obtain the acceleration an +1 of the next servo period; otherwise, directly taking the estimated acceleration and deceleration state value of the next servo period as the acceleration an +1 of the next servo period;

and the position and speed calculation program unit is used for calculating the position sn +1 and the speed vn +1 of the next servo period according to the acceleration an +1 of the next servo period.

In addition, the present embodiment also provides an online acceleration and deceleration control system for a pointing mechanism, which includes a computer device programmed or configured to execute the steps of the online acceleration and deceleration control method for a pointing mechanism of the present embodiment, or a computer program programmed or configured on a storage medium of the computer device to execute the online acceleration and deceleration control method for a pointing mechanism of the present embodiment.

furthermore, the present embodiment also provides a computer-readable storage medium, which is programmed or configured to execute the computer program of the online acceleration and deceleration control method for a pointing mechanism of the present embodiment.

as will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

the above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.