A method and system for automatic ship driving

Abstract

The present invention discloses a method and system for automatic ship driving. The method includes calculating the difference between the target heading and the current true heading; calculating the product of the difference between the target heading and the current true heading and the yaw factor Ke, and performing differential processing on the difference between the target heading and the current true heading, and then calculating the product of the differential result and the differential factor Kd; using a preset fuzzy rule to divide the product of the difference and the yaw factor Ke, and the product of the differential result and the differential factor Kd into a fuzzy value, and generating an output item according to the two fuzzy values; calculating the product of the output item and the proportional factor Kp, and performing integral processing on the output item to obtain the integral result, and then calculating the product of the integral result and the integral factor Ki; calculating the target rudder angle, and controlling the ship's steering gear to work according to the target rudder angle. The present invention can enable the ship automatic driving control algorithm to adapt to more ship types and sea conditions, greatly improving the universality and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of ship automatic driving, and in particular to a ship automatic driving method and system. Background Art

[0002] At present, the ship automatic driving control technology mainly uses the traditional proportional-differential-integral (PID) control, which requires manual adjustment of parameters according to factors such as the ship's load, draft, speed and wind speed. It has the characteristics of simple structure and easy adjustment of parameters. However, PID control cannot automatically adapt to changes in ship status and sea conditions, and its parameters need to be frequently modified manually to adapt to the current ship and sea conditions, which places high demands on users; if it is not adjusted immediately, it will lead to poor control performance, which is often manifested as excessive steering amplitude, frequent steering, accelerated aging of the steering gear, and frequent turns, which give the crew a bad experience and even create danger in serious cases. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for automatic ship driving in view of the deficiencies in the prior art.

[0004] To achieve the above objectives, in a first aspect, the present invention provides a method for automatic ship driving, comprising:

[0005] Setting the target heading of the ship, collecting the current true heading of the ship, and then calculating the difference between the target heading and the current true heading;

[0006] Calculate the product of the difference between the target heading and the current true heading and the yaw factor Ke, perform differentiation processing on the difference between the target heading and the current true heading to obtain a differential result, and then calculate the product of the differential result and the differential factor Kd;

[0007] The preset fuzzy rules are used to divide the product of the difference and the yaw factor Ke, and the product of the differential result and the differential factor Kd into a fuzzy value respectively, and the output item Output is generated according to the two fuzzy values;

[0008] Calculate the product of the output item Output and the proportional factor Kp, integrate the output item Output to obtain an integral result, and then calculate the product of the integral result and the integral factor Ki;

[0009] Calculate the target rudder angle rudder=Output(t)*Kp+(Output(t)+Output(t-1)+Output(t-2)…Output(0))*Ki, where t represents the current moment, and control the steering gear of the ship to work according to the target rudder angle.

[0010] Furthermore, the fuzzy value includes a negative maximum value, a negative median value, a negative minimum value, zero, a positive minimum value, a positive median value, and a positive maximum value.

[0011] Furthermore, the negative maximum value is -6, the negative median value is -4, the negative minimum value is -2, the positive minimum value is 2, the positive median value is 4, and the positive maximum value is 6.

[0012] Furthermore, the fuzzy value is divided as follows:

[0013]

[0014] in, is the fuzzy value divided, It is the product of the difference and Ke or the product of the differential result and Kd.

[0015] Furthermore, the yaw factor Ke is 0.2, the differential factor Kd is 2, the proportional factor Kp is 5, and the integral factor is 0.25.

[0016] In a second aspect, the present invention provides an automatic ship driving system, comprising:

[0017] A setting module, used to set the target course of the ship;

[0018] The acquisition module is used to collect the current true heading of the ship;

[0019] A first calculation module is used to calculate the difference between the target heading and the current true heading, calculate the product of the difference between the target heading and the current true heading and the yaw factor Ke, perform differential processing on the difference between the target heading and the current true heading to obtain a differential result, and then calculate the product of the differential result and the differential factor Kd;

[0020] A fuzzy controller is used to divide the product of the difference and the yaw factor Ke and the product of the differential result and the differential factor Kd into a fuzzy value according to a preset fuzzy rule, and generate an output item Output according to the two fuzzy values;

[0021] The second calculation module is used to calculate the product of the output item Output and the proportional factor Kp, and integrate the output item Output to obtain an integral result, and then calculate the product of the integral result and the integral factor Ki; and calculate the target rudder angle rudder=Output(t)*Kp+(Output(t)+Output(t-1)+Output(t-2)…Output(0))*Ki, where t represents the current time;

[0022] The steering gear control module is used to control the steering gear of the ship to work according to the target rudder angle.

[0023] Furthermore, the fuzzy value includes a negative maximum value, a negative median value, a negative minimum value, zero, a positive minimum value, a positive median value, and a positive maximum value.

[0024] Furthermore, the negative maximum value is -6, the negative median value is -4, the negative minimum value is -2, the positive minimum value is 2, the positive median value is 4, and the positive maximum value is 6.

[0025] Furthermore, the fuzzy value is divided as follows:

[0026]

[0027] in, is the fuzzy value divided, It is the product of the difference and Ke or the product of the differential result and Kd.

[0028] Furthermore, the yaw factor Ke takes a value of 0.2, the differential factor Kd takes a value of 2, the proportional factor Kp takes a value of 5, and the integral factor Ki takes a value of 0.25.

[0029] Beneficial effects: The present invention adopts a fuzzy control algorithm to fuzzy the input parameters, and designs corresponding control rules based on the driving experience of professionals, establishes the changing relationship between the control input and output, and can convert it into an automatic control strategy according to the set control rules, so that the ship automatic driving control algorithm can adapt to more ship types and sea conditions, greatly improving the universality and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of an automatic ship driving system according to an embodiment of the present invention;

[0031] Figure 2 This is a comparison diagram of the rudder angle changes between the present invention and PID regulation in Matlab simulation;

[0032] Figure 3 This is a comparison diagram of the turning rate changes of the present invention and PID regulation in Matlab simulation;

[0033] Figure 4 It is a comparison diagram of the course change between the present invention and PID regulation in Matlab simulation. DETAILED DESCRIPTION

[0034] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0035] An embodiment of the present invention provides a method for automatic ship driving, including:

[0036] The target heading of the ship is set, and the current true heading of the ship is collected, and then the difference e between the target heading and the current true heading is calculated.

[0037] Calculate the product Ve of the difference e between the target heading and the current true heading and the yaw factor Ke. The product Ve can be expressed as: Ve=Ke*e. Differentiate the difference e between the target heading and the current true heading to obtain the differential result ∇e, and then calculate the product Vd of the differential result and the differential factor Kd. The product can be expressed as: Vd = ∇e*Kd.

[0038] The preset fuzzy rules are used to divide the product Ve of the difference e and the yaw factor Ke, and the product Vd of the differential result and the differential factor Kd into a fuzzy value respectively, and the output item Output is generated according to the two fuzzy values. Specifically, the above fuzzy values ​​include negative maximum value (NL), negative median value (NM), negative minimum value (NS), zero (ZO), positive minimum value (PS), positive median value (PM), and positive maximum value (PL). As a preferred embodiment, the values ​​of each of the above are as follows: the negative maximum value is -6, the negative median value is -4, the negative minimum value is -2, the positive minimum value is 2, the positive median value is 4, and the positive maximum value is 6. The specific division method of the fuzzy value is as follows:

[0039]

[0040] in, is the fuzzy value divided, It is the product of the difference e and Ke or the product of the differential result and Kd.

[0041] When generating the output item Output, it can be generated according to the preset fuzzy rule table matching, as shown in Table 1:

[0042] Table 1: Fuzzy rules table

[0043]

[0044] The product of the output item Output and the proportional factor Kp is calculated, and the output item Output is integrated to obtain the integral result, and then the product of the integral result and the integral factor Ki is calculated.

[0045] Calculate the target rudder angle rudder=Output(t)*Kp+(Output(t)+Output(t-1)+Output(t-2)…Output(0))*Ki, where t represents the current moment, t-1 represents the previous moment, and so on, and control the ship's steering gear to work according to the calculated target rudder angle.

[0046] As a preferred embodiment, the yaw factor Ke is 0.2, the differential factor Kd is 2, the proportional factor Kp is 5, and the integral factor Ki is 0.25.

[0047] See also Figure 1 Based on the above embodiments, those skilled in the art can easily understand that the present invention also provides a ship automatic driving system, including a setting module 1, a collection module 2, a first calculation module 3, a fuzzy controller 4, a second calculation module 5 and a steering gear control module 6.

[0048] The setting module 1 is used to set the target heading of the ship.

[0049] The acquisition module 2 is used to acquire the current true heading of the ship.

[0050] The first calculation module 3 is used to calculate the product Ve of the difference e between the target heading and the current true heading and the yaw factor Ke, and the product Ve can be expressed as: Ve=Ke*e. The difference e between the target heading and the current true heading is differentiated to obtain a differential result ∇e, and then the product Vd of the differential result and the differential factor Kd is calculated, and the product Vd can be expressed as: Vd=∇e*Kd.

[0051] The fuzzy controller 4 is used to divide the product Ve of the difference e and the yaw factor Ke, and the product Vd of the differential result and the differential factor Kd into a fuzzy value according to the preset fuzzy rules, and generate the output item Output according to the two fuzzy values. Specifically, the above fuzzy values ​​include negative maximum value (NL), negative median value (NM), negative minimum value (NS), zero (ZO), positive minimum value (PS), positive median value (PM), and positive maximum value (PL). As a preferred embodiment, the values ​​of each of the above are as follows: the negative maximum value is -6, the negative median value is -4, the negative minimum value is -2, the positive minimum value is 2, the positive median value is 4, and the positive maximum value is 6. The specific division method of the fuzzy value is as follows:

[0052]

[0053] in, is the fuzzy value divided, It is the product of the difference e and Ke or the product of the differential result and Kd.

[0054] When generating the output item Output, it can be generated according to the preset fuzzy rule table matching, as shown in Table 1 for details.

[0055] The second calculation module 5 is used to calculate the product of the output item Output and the proportional factor Kp, and integrate the output item Output to obtain the integral result, and then calculate the product of the integral result and the integral factor Ki; and calculate the target rudder angle rudder=Output(t)*Kp+(Output(t)+Output(t-1)+Output(t-2)…Output(0))*Ki, where t represents the current moment, t-1 represents the previous moment, and so on.

[0056] The steering gear control module 6 is used to control the steering gear of the ship to work according to the target rudder angle.

[0057] As a preferred embodiment, the yaw factor Ke is 0.2, the differential factor Kd is 2, the proportional factor Kp is 5, and the integral factor Ki is 0.25.

[0058] In the Matlab simulation, under the same conditions, the ship is also simulated to turn 80 degrees. The results are as follows: Figures 2 to 4 It can be seen that the traditional PID control has a large steering angle and a high turning rate, which will bring a poor control experience to the user, and there will be obvious overshoot after reaching the target heading, and there will be multiple back and forth oscillations; while the steering angle of the present invention is smaller and its turning rate is limited, so it can stabilize on the target heading faster.

[0059] The above is only a preferred embodiment of the present invention. It should be noted that for ordinary technicians in this technical field, other parts not specifically described belong to the prior art or common knowledge. Several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A method for automatic ship driving, characterized in that: include: Setting the target heading of the ship, collecting the current true heading of the ship, and then calculating the difference between the target heading and the current true heading; Calculate the product of the difference between the target heading and the current true heading and the yaw factor Ke, perform differentiation processing on the difference between the target heading and the current true heading to obtain a differential result, and then calculate the product of the differential result and the differential factor Kd; The preset fuzzy rules are used to divide the product of the difference and the yaw factor Ke, and the product of the differential result and the differential factor Kd into a fuzzy value respectively, and the output item Output is generated according to the two fuzzy values; Calculate the product of the output item Output and the proportional factor Kp, integrate the output item Output to obtain an integral result, and then calculate the product of the integral result and the integral factor Ki; Calculate the target rudder angle rudder=Output(t)*Kp+(Output(t)+Output(t-1)+Output(t-2)…Output(0))*Ki, where t represents the current moment, and control the steering gear of the ship to work according to the target rudder angle.

2. A method for automatic ship driving according to claim 1, characterized in that: The fuzzy values ​​include a negative maximum value, a negative middle value, a negative minimum value, zero, a positive minimum value, a positive middle value, and a positive maximum value.

3. A method for automatic ship driving according to claim 2, characterized in that: The negative maximum value is -6, the negative median value is -4, the negative minimum value is -2, the positive minimum value is 2, the positive median value is 4, and the positive maximum value is 6.

4. A method for automatic ship driving according to claim 3, characterized in that: The fuzzy value is divided as follows: ； in, is the fuzzy value divided, It is the product of the difference and Ke or the product of the differential result and Kd.

5. The method for automatic ship driving according to claim 1, characterized in that: The yaw factor Ke is 0.2, the differential factor Kd is 2, the proportional factor Kp is 5, and the integral factor is 0.

25.

6. A ship automatic driving system, characterized in that: include: A setting module, used to set the target course of the ship; The acquisition module is used to collect the current true heading of the ship; A first calculation module is used to calculate the difference between the target heading and the current true heading, calculate the product of the difference between the target heading and the current true heading and the yaw factor Ke, perform differential processing on the difference between the target heading and the current true heading to obtain a differential result, and then calculate the product of the differential result and the differential factor Kd; A fuzzy controller is used to divide the product of the difference and the yaw factor Ke and the product of the differential result and the differential factor Kd into a fuzzy value according to a preset fuzzy rule, and generate an output item Output according to the two fuzzy values; A second calculation module is used to calculate the product of the output item Output and the proportional factor Kp, integrate the output item Output to obtain an integral result, and then calculate the product of the integral result and the integral factor Ki; And calculate the target rudder angle rudder=Output(t)*Kp+(Output(t)+Output(t-1)+Output(t-2)…Output(0))*Ki, where t represents the current moment; The steering gear control module is used to control the steering gear of the ship to work according to the target rudder angle.

7. The ship automatic driving system according to claim 6, characterized in that: The fuzzy values ​​include a negative maximum value, a negative median value, a negative minimum value, zero, a positive minimum value, a positive median value, and a positive maximum value.

8. The ship automatic driving system according to claim 7, characterized in that: The negative maximum value is -6, the negative median value is -4, the negative minimum value is -2, the positive minimum value is 2, the positive median value is 4, and the positive maximum value is 6.

9. A ship automatic driving system according to claim 8, characterized in that: The fuzzy value is divided as follows: ； in, is the fuzzy value divided, It is the product of the difference and Ke or the product of the differential result and Kd.

10. The ship automatic driving system according to claim 6, characterized in that: The yaw factor Ke takes a value of 0.2, the differential factor Kd takes a value of 2, the proportional factor Kp takes a value of 5, and the integral factor Ki takes a value of 0.25.

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