JPS5937280B2 - steering gear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering system for a ship, and more particularly to a compensation means for improving the maneuverability of a ship.

As is well known, in large ships, especially wide and thick ships, the steady characteristic of turning angular velocity per rudder angle becomes as shown in FIG. 1, and the turning angular velocity becomes a multivalued function of the rudder angle. Figure 1 shows a steady characteristic diagram of the turning angular velocity per rudder angle in a wide and enlarged ship obtained from the reverse spiral test, where the horizontal axis is the rudder angle (δ) and the vertical axis is the turning angular velocity (γ). Generally, such ships are called unstable course ships, and they have the following disadvantages when maneuvering. That is, even if the rudder angle is zero, the turning angular velocity gradually diverges, making it particularly difficult to probe. In other words, in manual steering, course deviations due to course instability are added to course deviations due to disturbances, and large steering is frequently required. Furthermore, in automatic steering, if the time constant of the differential element is not sufficiently large, the course will diverge. This inconvenience can be solved by making the steady characteristic of the turning angular velocity per steering angle a single-valued function so that when the steering angle is set to zero, the turning angular velocity converges to zero for any initial state. be done. Conventionally,
As a solution to this problem, a control system as shown in FIG. 2 is known. That is, a command signal from the steering wheel or a command signal equivalent thereto (command rudder angle) δ and a turning angular velocity signal γ given from the hull 2 through the feedback loop system 3
The steering angle δ is obtained by inputting the deviation signal from the steering gear 1 to the steering gear 1. At this time, the closer the feedback gain KF is, the better the stability is. FIG. 3 shows an example of the steady-state characteristics of the steering angle and head angular velocity obtained by the method shown in FIG. 2. If the input/output steady-state characteristics of the steering gear 1 are linear, then Figure 3 shows the difference between δ and γ in Figure 1.
It can be seen that the curve can be obtained by moving the curve in parallel by KF×γ in the δ direction. On the other hand, by using the control system shown in FIG. 2 for a ship whose course is stable, it is effective to further stabilize the probe.

That is, this functions in the same way as the differential element in automatic steering, and compensates for phase delays due to weather adjustments such as backlash. In addition, with a manual probe, the helmsman always calculates the turning angular velocity in his head based on the movement of the compass card and performs the corresponding steering, but by using the control system shown in Figure 2, the turning angular velocity can be calculated by using the control system shown in Figure 2. Since the information is fed back, the burden on the helmsman can be reduced. As described above, the control system shown in FIG. 2 is effective in keeping the course not only for ships with unstable course but also for ships with stable course, but it has the following drawbacks. In other words, a fast course change using a large rudder angle is required. In this case, the rise of the turning angular velocity is slow. Furthermore, as can be seen from FIG. 3, a large turning angular velocity cannot be obtained even on a steady basis. Furthermore, as is clear from FIG. 9, which will be described later, in the control system shown in FIG. 2, the commanded steering angle δ and the actual steering angle δ are generally very different. For this reason, when the steering is performed during a large steering angle change, a larger steering is performed than the command signal, which is unfavorable in terms of steering. The present invention was developed in order to solve the above-mentioned drawbacks of the prior art shown in FIG. For steering using a rudder angle, a steering device is provided that enables rapid course changes.

FIG. 4 is a block diagram showing an embodiment of the steering system according to the present invention.

In the figure, 1 is a steering gear, 2 is a hull, 4 is a function generator,
5 is an automatic gain adjustment device that realizes the gain of the function generator 4. An example of the function type of the function generator 4 used in the present invention is shown in FIG. That is, in the present invention, the turning angle signal γ from the hull 2 is input to the automatic gain adjustment device 5 of the feedback loop, and the function generator 4 generates a command signal from the steering wheel or a command signal equivalent thereto (command rudder angle ) The gain KF of the automatic gain adjustment device 5 is changed according to the magnitude of the command signal δ, and when the command signal δ is large, the output signal KF and γ of the automatic gain adjustment device 5 is suppressed to almost zero, and when the command signal δ is small, In this case, the gain KF is increased, and the deviation signal between the output signal KF·γ and the command signal δ is used as the human power of the steering machine 1. FIG. 6 shows the steady-state characteristic of the angular velocity per steering angle when the embodiment of the present invention shown in FIG. 4 is used, and it can be seen that the characteristic is sufficiently improved compared to FIGS. 1 and 3. Furthermore, in the cases shown in Fig. 2 and Fig. 4, the response of the turning angular velocity when a step-like command rudder angle δ is applied is shown in Fig. 7 and Fig. 8, and the response of the actual rudder angle is shown in Fig. 9. and shown in FIG. 6th to 10th
From the figure, it can be seen that in the present invention, the turning angular velocity rises quickly when the steering angle is large, and the actual steering angle almost matches the command steering angle. That is, in the present invention, when the command signal from the steering wheel or the command signal δ corresponding thereto has a small value, it is stabilized by a sufficiently large feedback gain, thereby facilitating course keeping, etc. In addition, when δ is a large value, by setting the feedback gain to almost zero, prompt course changes are possible, and the steering input remains as δ, and the command signal is output as in the system shown in Figure 2. There will be no major turning. By continuously changing the feedback gain during that time, the steering gear 1 does not require a step input. As described above, according to the present invention, it is possible to realize manual steering and white dynamic steering that have sufficient stability in course keeping, enable prompt course changes, and do not put strain on the steering gear.

[Brief explanation of drawings]

Figure 1 is a steady-state characteristic diagram of turning angular velocity per rudder angle for a ship with an unstable course obtained from a reverse spiral test, and Figure 2 is a deviation signal between the command signal from the steering wheel or an equivalent command signal and the turning angular velocity signal. FIG. 3 is a plotter diagram of a conventional steering system that stabilizes the steering system as a steering input, FIG. 3 is a steady-state characteristic of steering angle and turning angular velocity when using the conventional technology shown in FIG. 2, and FIG. A block diagram showing one embodiment, FIG. 5 is a human output characteristic diagram of the function generator used in FIG. 4, and FIG.
The figure shows an example of steady-state characteristics of turning angular velocity per steering angle when using the present invention, and Figures R and 9 show the steps of turning angular velocity and actual steering angle when using the prior art shown in Figure 2, respectively. Figures 8 and 10 showing the response are diagrams showing the step response of the turning angular velocity and the actual steering angle when the present invention is used. 1... Steering gear, 2... Hull, 3...
. . . Feedback loop system, 4 . . . Function generator, 5 . . . Motion gain adjustment device.

Claims (1)

[Claims] 1. In a device that calculates the deviation between a command signal from a steering wheel or a command signal equivalent thereto (hereinafter referred to as a rudder angle command signal) and a turning angular velocity signal of the ship, and uses the deviation signal as input to a steering gear to steer the ship, Input the turning angular velocity signal of the ship and multiply it by K_F (here, K_F is the gain)
an automatic gain adjustment means for outputting a signal, and a gain of the automatic gain adjustment means is changed in accordance with the steering angle command signal, and the gain is increased in a range where the steering angle command signal is small;
function generating means for reducing the gain to approximately zero when the steering angle command signal becomes larger than a predetermined value; A steering device characterized in that it is an input.