X-shaped rudder angle distribution method suitable for underwater vehicle

Abstract

The invention relates to an X-shaped rudder angle distribution method suitable for an underwater vehicle, and solves the problem of X-shaped rudder angle distribution aiming at the condition that a traditional cross-shaped rudder distribution algorithm is not suitable for an X-shaped rudder. After a required rudder angle is calculated according to a real-time attitude and a control instruction of the underwater vehicle, the influence of rolling of the vehicle on the steering effect is considered, rudder angle distribution is performed on four steering engines of the X-shaped rudder according to the corresponding steering effect, and a steering instruction of the X-shaped rudder of the underwater vehicle is obtained. According to the method, the difference between the integral structure and the control surface distribution form of the steering engine of the cross-shaped rudder and the X-shaped rudder is considered, a rudder angle distribution algorithm of a traditional cross-shaped rudder is abandoned, aiming at the unique control surface distribution form of the X-shaped rudder, the influence of the rolling angle of the navigation body on the rudder effect of the X-shaped rudder is comprehensively considered, the rudder angle distribution algorithm of the X-shaped rudder is redesigned, and the design of the rudder angle distribution algorithm of the X-shaped rudder is optimized. Therefore, the maneuvering characteristics of the underwater navigation body are improved, and guarantee is provided for operation of the underwater navigation body under severe conditions.

Description

Technical Field

[0001] The invention relates to a steering gear rudder angle allocation algorithm for a navigation system of a vehicle, and belongs to the technical field of steering gear control of a navigation system. Background Art

[0002] The X-type rudder refers to a rudder distribution form in which four rudders are spaced 90° apart and evenly arranged on the diagonal line of the tail of the navigation body. The X-type rudder structure is shown in Figure 1. However, most existing underwater navigation bodies use cross-shaped rudders, which have many disadvantages in maneuverability and stability compared to the X-shaped rudder. Compared with the traditional cross-shaped rudder, the X-shaped rudder has the following advantages: its rudder surface is longer, making its rudder efficiency 30%-40% higher than that of the cross-shaped rudder; and each of its rudder surfaces can be controlled separately, even if one or two rudder surfaces are damaged, the navigation body can still work normally, and the safety performance is higher; secondly, the maneuverability of the X-shaped rudder under high-speed navigation conditions also has obvious advantages.

[0003] The traditional cross-type steering gear system structure will design the rudder plate and the fin plate as an integrated structure, that is, the rudder plate is embedded in the fin plate. The X-type steering gear system structure separates the fin plate from the rudder plate, such as Figure 1a , as shown in a and b. This characteristic makes the fluid dynamic characteristics of the navigation body equipped with an X-type rudder quite different from those of the navigation body equipped with a cross-type rudder. This difference in structural design also makes the shape, area, and activity limit angle of the X-type rudder blade different from those of the cross-type rudder. The resulting influence makes the rudder angle allocation algorithm suitable for the X-type rudder not simply generalized from the cross-type rudder angle allocation algorithm. In order to improve the control efficiency and performance of the X-type rudder, it is necessary to study its rudder angle allocation method. The rudder angle allocation algorithm of the X-type rudder is more complicated, and it is necessary to consider the influence of the rolling angle of the navigation body on its rudder effect and the limitation of the mechanical activity angle. Therefore, the rudder angle allocation algorithm of the X-type rudder needs to be redesigned. Summary of the invention

[0004] In view of this, the present invention proposes a method for allocating rudder angles of X-type rudders applicable to underwater vehicles. The present invention solves the problem of rudder angle allocation of X-type rudders, which is applicable to the situation that the allocation algorithm of traditional cross-type rudders cannot be applied to X-type rudders, thereby improving the maneuverability of underwater vehicles and providing guarantee for the operation of underwater vehicles under harsh conditions.

[0005] The invention calculates the required rudder angle according to the real-time attitude and control instructions of the underwater vehicle, considers the influence of the rolling of the vehicle on the rudder effect, distributes the rudder angles to the four servos of the X-type rudder according to the corresponding rudder effect, and obtains the steering instruction of the X-type rudder of the underwater vehicle.

[0006] The specific technical solutions are as follows:

[0007] A rudder angle distribution method for an X-type rudder applicable to an underwater vehicle calculates the required vertical, horizontal and differential rudder angles according to the real-time attitude and control instructions of the underwater vehicle, distributes the rudder angles to four servos of the X-type rudder according to the corresponding rudder effects, and obtains the X-type rudder steering instructions.

[0008] Furthermore, the real-time posture of the underwater vehicle is obtained by acquiring the angle and angular velocity information on the three channels of yaw, pitch and roll of the underwater vehicle in real time through a built-in inertial navigation device.

[0009] Furthermore, the control instructions of the underwater vehicle are angle control instructions on three channels of yaw, pitch and roll that are solved in real time by the navigation control system based on the underwater vehicle's own attitude and orientation and the attitude and orientation of the target point.

[0010] Furthermore, the vertical, horizontal and differential steering angles refer to the steering angles in the absolute horizontal and vertical planes in the navigation coordinate system required for the underwater vehicle to complete the control instructions, which are intermediate quantities for calculating the final steering angle distribution.

[0011] Furthermore, the allocation of the rudder angles of the four servos of the X-type rudder according to the corresponding rudder effects refers to calculating the angle between the four servos of the X-type rudder and the Z-axis of the navigation coordinate system by the angle between the underwater vehicle carrier coordinate system and the navigation coordinate system, and then allocating the actual rudder angle according to the angle relationship and the vertical, horizontal and differential rudder angle values.

[0012] Furthermore, the X-type rudder angle allocation algorithm is as follows:

[0013] Observe from the tail to the head of the underwater vehicle, take the intersection of the extension lines of the rudder surface at the tail of the vehicle as the origin, and establish a plane rectangular coordinate system as the initial coordinate system xoz of the X-type rudder;

[0014] Define the same direction rudder angle, differential rudder angle and vertical, horizontal and differential rudder effects of X-type rudder in xoz;

[0015] Get the numerical relationship between the same direction rudder angle, differential rudder angle and vertical, horizontal and differential rudder effects;

[0016] Without considering the differential rudder, the four rudder angles of the X-type rudder are preliminarily distributed and limited;

[0017] On the basis of the preliminary allocation, differential rudder angle allocation is performed according to the deflection degree of the two pairs of rudders, and the differential effect is distributed to the four rudders;

[0018] The rudder angle after the differential effect is distributed is limited to obtain the final rudder angle distribution value.

[0019] Beneficial Effects

[0020] 1. The present invention takes into account the differences in the overall structure and rudder surface distribution of the cross-type rudder and the X-type rudder, abandons the rudder angle allocation algorithm of the traditional cross-type rudder, and redesigns the rudder angle allocation algorithm of the X-type rudder based on the unique rudder surface distribution of the X-type rudder and the influence of the rolling angle of the navigation body on the rudder effect of the X-type rudder.

[0021] 2. Through the allocation method, the advantages of the X-type rudder's high rudder efficiency and independent control of the rudder surface are brought into play, thereby improving the maneuverability of the underwater vehicle and providing guarantee for the operation of the underwater vehicle under harsh conditions.

[0022] 3. The X-type rudder angle distribution method of the present invention has been verified by simulation data. The simulation results are as follows: Figure 2 The underwater vehicle's heading-changing navigation capability under three different working conditions was simulated, and the results are shown in Figure 3 shown. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1a X-type rudder layout rear view

[0024] Figure 1b Schematic diagram of X-shaped rudder layout

[0025] Figure 2 Simulation diagram of depth control under three working conditions of X-type rudder

[0026] Figure 3 Simulation diagram of heading control under three working conditions of X-type rudder

[0027] Figure 4 Schematic diagram of calculation of rudder angle distribution for X-type rudder

[0028] Figure 5 Flowchart of X-type rudder angle distribution algorithm DETAILED DESCRIPTION

[0029] Taking the underwater vehicle with X-shaped rudder as an example, Figure 5 Description of implementation method:

[0030] Observing from the tail to the head of the underwater vehicle, the X-shaped rudder layout is as follows Figure 4 As shown in the figure, the intersection of the extension lines of the tail rudder surface of the vehicle is taken as the origin, and the xoz coordinate system is established at the initial attitude of the vehicle. If the vehicle rolls around the origin at a certain moment Then the z axis rotates to the z′ axis, and we define is the real-time roll angle of the underwater vehicle. Since the existence of the roll angle will affect the steering effect of the X-type rudder, the influence of the small U roll angle should be taken into account when allocating the rudder angle.

[0031] Divide the four rudder surfaces into two pairs, where δ 1t , δ 3t For a pair, δ 2t , δ 4t For another pair. When the rudder surface is deflected, the two rudder surfaces of each pair of rudders are defined as unidirectional rudders when they are deflected in the same direction, and as differential rudders when they are deflected in opposite directions; when each pair of rudders is ruddered in the same direction, the average of the sum of the deflection angles of the two rudder surfaces is the equivalent unidirectional rudder angle of the two rudders; when each pair of rudders is ruddered in opposite directions, the average of the difference in the deflection angles of the two rudder surfaces is the equivalent differential rudder angle of the two rudders; then:

[0032] δ 1t , δ 3t The equivalent rudder angle in the same direction is δ 13st =(δ 1t +δ 3t ) / 2, from δ 3t Rudder 1t Looking from the rudder direction, right deviation is positive and left deviation is negative; 1t , δ 3t The equivalent differential steering angle is δ 13dt =(δ 1t -δ 3t ) / 2, from δ 3t Rudder 1t Looking from the rudder direction, δ 1t Right deviation, δ 3t Left deviation is positive, and the opposite is negative;

[0033] δ 2t , δ 4t The equivalent rudder angle in the same direction is δ 24st =(δ 2t +δ 4t ) / 2, from δ 4t Rudder 2t Looking from the rudder direction, right deviation is positive and left deviation is negative; 2t , δ 4t The equivalent differential steering angle is δ 24dt =(δ 2t -δ 4t ) / 2, from δ 4t Rudder 2t Looking from the rudder direction, δ 2t Right deviation, δ 4t Left deviation is positive, left deviation is negative.

[0034] make but

[0035] δ 13st The horizontal rudder effect projected on the x-axis is δ 13st sinυ t , the vertical rudder effect projected on the z-axis is δ 13st cosυt ;

[0036] δ 24st The horizontal rudder effect projected on the x-axis is δ 24st cosυ t , the vertical rudder effect projected on the z-axis is -δ 24st sinυ t .

[0037] Define the vertical rudder effect of the X-type rudder projected in the xoz coordinate system as δ vt , the horizontal rudder effect is δ ht , the differential steering effect is δ dt , δ vt , δ ht , δ dt It can be obtained from the navigation body attitude and is used as a known variable input of the rudder angle allocation algorithm in the present invention. 13st , δ 24st The following quantitative relationships exist:

[0038]

[0039] From the above formula, we can get:

[0040]

[0041] Without considering the differential steering, that is, δ 13dt =δ 24dt =0, that is, δ 1t =δ 3t , δ 2t =δ 4t , then assigned to δ 1t , δ 2t , δ 3t , δ 4t The rudder angles of the four rudders are:

[0042]

[0043] The principle of differential rudder distribution and rudder angle limitation is that the final output to δ 1t , δ 2t , δ 3t , δ 4t The rudder angles of the four rudders cannot exceed the maximum rudder angle limit, nor can they produce unexpected differential rudder angles. Based on this principle, the limiting and distribution process is as follows:

[0044] Since the X-type rudder system has a mechanical deflection limit, in order to protect the rudder, δ′ in (3) 1t ,δ′ 2t ,δ′ 3t ,δ′ 4t Limiting gives:

[0045]

[0046] δ″ 3t =δ″ 1t

[0047] δ″ 4t =δ″ 2t (4)

[0048] 1)min(|δ″ 1t |,|δ″ 2t |)=|δ″ 1t |In the case of 0.5235-|δ″, among the two pairs of rudders, the rudder angle deflection degree of rudders 1 and 3 is small, and the rudder angle margin is large. The required differential rudder angle is allocated to rudders 1 and 3 first. 1t |≥|δ dt |, then the required differential rudder angle can be all allocated to rudders 1 and 3, as follows:

[0049]

[0050] If there is 0.5235-|δ″ 1t |<|δ dt |, the required differential rudder angle is first distributed to part of rudders 1 and 3, and the remaining part is distributed to rudders 2 and 4, which is:

[0051]

[0052] For δ″ in (6) 1t ,δ dt The symbols discussed are:

[0053]

[0054]

[0055] Considering the mechanical deflection limit of the steering gear, 2 ' t , δ 4 ' t Limiting gives:

[0056]

[0057] 2)min(|δ″ 1t |,|δ″ 2t |)=|δ″ 2t |In this case, the allocation method is similar to the above method.

Claims

1. A method for allocating rudder angles of an X-shaped rudder applicable to an underwater vehicle, characterized in that: After calculating the required vertical, horizontal and differential rudder angles according to the real-time attitude and control instructions of the underwater vehicle, the rudder angles are allocated to the four servos of the X-type rudder according to the corresponding rudder effects to obtain the X-type rudder steering instructions.

2. A method for allocating rudder angles of an X-shaped rudder applicable to an underwater vehicle according to claim 1, characterized in that: The real-time attitude of the underwater vehicle is obtained by acquiring the angle and angular velocity information on the three channels of yaw, pitch and roll of the underwater vehicle in real time through a built-in inertial navigation device.

3. A method for allocating rudder angles of an X-shaped rudder applicable to an underwater vehicle according to claim 1, characterized in that: The control instructions of the underwater vehicle are angle control instructions on three channels of yaw, pitch and roll that are solved in real time by the navigation control system according to the attitude and orientation of the underwater vehicle itself and the attitude and orientation of the target point.

4. A method for allocating rudder angles of an X-shaped rudder applicable to an underwater vehicle according to claim 1, characterized in that: The vertical, horizontal and differential steering angles refer to the steering angles in the absolute horizontal and vertical planes in the navigation coordinate system required for the underwater vehicle to complete the control instructions, and are intermediate quantities for calculating the final steering angle distribution.

5. A method for allocating rudder angles of an X-shaped rudder applicable to an underwater vehicle according to claim 1, characterized in that: The described distribution of the rudder angles of the four servos of the X-type rudder according to the corresponding rudder effects refers to calculating the angle between the four servos of the X-type rudder and the Z-axis of the navigation coordinate system by the angle between the underwater vehicle carrier coordinate system and the navigation coordinate system, and then distributing the actual rudder angle according to the angle relationship and the vertical, horizontal and differential rudder angle values.

6. A method for allocating rudder angles of an X-shaped rudder applicable to an underwater vehicle according to any one of claims 1 to 5, characterized in that: The specific algorithm for assigning the rudder angle of the X-type rudder is as follows: Observe from the tail to the head of the underwater vehicle, take the intersection of the extension lines of the rudder surface at the tail of the vehicle as the origin, and establish a plane rectangular coordinate system as the initial coordinate system xoz of the X-type rudder; Define the same direction rudder angle, differential rudder angle and vertical, horizontal and differential rudder effects of X-type rudder in xoz; Get the numerical relationship between the same direction rudder angle, differential rudder angle and vertical, horizontal and differential rudder effects; Without considering the differential rudder, the four rudder angles of the X-type rudder are distributed and limited.

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