Control device for moving body, moving body, control method for moving body, and program

Abstract

This control device for a moving body is provided with: a switching unit that switches between a manual mode in which a torque limit value is set manually by an operator and an auto mode in which the torque limit value is set automatically; a manual setting unit that, when the control device is switched to the manual mode, sets the torque limit value to a value specified by the operator; an automatic setting unit that, when the control device is switched to the auto mode, sets the torque limit value on the basis of at least one of the load torque transmitted from a propulsion unit to a magnetic geared motor and measurement data representing the state of the moving body; and a limiter that limits, by the torque limit value, a torque command for adjusting the electric torque of the magnetic geared motor, on the basis of the difference between a rotation speed command that specifies the rotation speed of the propulsion unit and measurement data of the rotation speed of the propulsion unit.

Description

MOBILE BODY CONTROL DEVICE, MOBILE BODY ... CONTROL METHOD, AND PROGRAM

[0001] This application claims priority to Japanese Patent Application No. 2023-133460, filed on August 18, 2023, the contents of which are incorporated herein by reference.

[0002] 2. Description of the Related Art Mobile bodies such as ships and vehicles are equipped with propulsion systems that allow the mobile bodies to move in any direction and at any speed (see, for example, Patent Document 1).

[0003] In recent years, the electrification of propulsion systems for moving bodies such as ships and vehicles has been progressing. For example, in the case of ships, electric motors offer greater flexibility in placement compared to existing diesel engines and steam turbines, and when combined with storage batteries, they are expected to offer improved efficiency and reliability.

[0004] To use an electric motor, it is necessary to use a mechanical reducer or a specially designed electric motor with a low rated speed to adjust the rotation speed to the required range of the propulsion device. However, using a mechanical reducer has disadvantages such as vibration and noise generation and the need for regular maintenance. In addition, when using a low-speed electric motor with a low rated speed, the size (diameter) of the electric motor increases due to the increased number of poles, which makes it difficult to install it on a moving body with limited installation space.

[0005] For this reason, the use of a magnetic geared motor as an electric motor has been considered. A magnetic geared motor has a magnetic gear unit consisting of a high-speed rotor and a low-speed rotor. The high-speed rotor and the low-speed rotor transmit torque contactlessly using a magnetic spring. This magnetic spring causes the low-speed rotor to rotate synchronously with the high-speed rotor at a predetermined reduction ratio. In other words, a magnetic geared motor can adjust its rotation speed to match the propulsion device without a mechanical reducer. Furthermore, because a magnetic geared motor can output the rotation speed required by the propulsion device without having to be as large in diameter as a typical electric motor (e.g., a synchronous motor), it can be applied to moving bodies with limited installation space.

[0006] Japanese Patent Application Laid-Open No. 2022-99788

[0007] On the other hand, when a magnetic geared motor experiences an overload due to foreign objects being caught in the rotor or a sudden reversal of the rotation, such as during a ship's crash or astern, that generates torque exceeding the maximum transmission torque of the magnetic spring, the high-speed and low-speed rotors may lose synchronization, resulting in a loss of torque transmission function. While the loss of synchronization is resolved automatically when the input energy is cut off, during the time it takes for the loss to be resolved, an alternating torque is generated whose amplitude is the maximum transmission torque and whose frequency is proportional to the electrical speed difference between the high-speed and low-speed rotors. This alternating torque may excite the natural vibration mode of the rotating shaft system of the magnetic geared motor. Exciting the natural vibration mode can result in noise from the rotating shaft system and even damage to the rotating shaft and surrounding equipment.

[0008] One way to prevent step-out is to increase the maximum transmission torque. While this is an essential and reliable method, increasing the maximum transmission torque requires increasing the amount of magnets in the magnetic gear section. This increases the size, weight, and cost of the magnetic geared motor, reducing its advantages over mechanical reducers and low-speed, large-diameter electric motors.

[0009] An object of the present disclosure is to provide a control device for a mobile body, a mobile body, a control method for a mobile body, and a program that can suppress loss of synchronization of a magnetic geared motor mounted on the mobile body.

[0010] According to one aspect of the present disclosure, a control device for a moving body is a control device for a moving body having a propeller that is rotationally driven by a magnetic geared motor, and includes: a switching unit that switches between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; a manual setting unit that, when switched to the manual mode, sets the torque limit value to a value specified by the operator; an automatic setting unit that, when switched to the auto mode, sets the torque limit value based on at least one of the load torque transmitted from the propeller to the magnetic geared motor and measurement data that represents the state of the moving body; and a limiter that limits, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor based on the difference between a rotation speed command that specifies the rotation speed of the propeller and the measurement data for the rotation speed of the propeller.

[0011] According to one aspect of the present disclosure, a control device for a moving body is a control device for a moving body having a propeller that is rotationally driven by a magnetic geared motor, and includes: a switching unit that switches between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; a manual setting unit that, when switched to the manual mode, sets the torque limit value to a value specified by the operator; an automatic setting unit that, when switched to the auto mode, sets the torque limit value based on at least one of a load torque transmitted from the propeller to the magnetic geared motor and measurement data that represents a state of the moving body; a limit value calculation unit that calculates, based on the torque limit value, a limit value that limits at least one of a rotation speed command that specifies the rotation speed of the propeller and a steering angle command that specifies the steering angle of the moving body; and a limiter that limits at least one of the rotation speed command and the steering angle command by the limit value.

[0012] According to one aspect of the present disclosure, a moving body includes a magnetic geared motor having a low-speed rotor and a high-speed rotor, a propeller driven to rotate by the magnetic geared motor, a steering gear that changes the direction of travel, and a control device according to the above-described aspect.

[0013] According to one aspect of the present disclosure, a method for controlling a moving body is a method for controlling a moving body having a propeller that is rotationally driven by a magnetic geared motor, and includes the steps of switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor and an auto mode in which the torque limit value is automatically set; when switched to the manual mode, setting the torque limit value to a value specified by the operator; when switched to the auto mode, setting the torque limit value based on at least one of a load torque transmitted from the propeller to the magnetic geared motor and measurement data representing a state of the moving body; and limiting, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor based on the difference between a rotation speed command that specifies the rotation speed of the propeller and the measurement data for the rotation speed of the propeller.

[0014] According to one aspect of the present disclosure, a program causes a control device of a moving body having a propeller driven by a magnetic geared motor to execute the following steps: switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; when switched to the manual mode, setting the torque limit value to a value specified by the operator; when switched to the auto mode, setting the torque limit value based on at least one of a load torque transmitted from the propeller to the magnetic geared motor and measurement data representing a state of the moving body; and limiting, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor based on the difference between a rotation speed command that specifies the rotation speed of the propeller and the measurement data for the rotation speed of the propeller.

[0015] According to the above aspect, it is possible to prevent the magnetic geared motor mounted on the moving body from losing synchronization.

[0016] 1 is a diagram showing the overall configuration of a moving body according to a first embodiment. FIG. 2 is a block diagram showing the functional configuration of a control device according to the first embodiment. FIG. 3 is a schematic diagram of a magnetic gear unit according to the first embodiment. FIG. 4 is a block diagram showing an example of control of a control device according to the first embodiment. FIG. 5 is a diagram for explaining the function of a switching unit according to the first embodiment. FIG. 6 is a block diagram showing an example of processing in auto mode according to the first embodiment. FIG. 7 is a block diagram showing an example of processing in auto mode according to the second embodiment. FIG. 8 is a block diagram showing the functional configuration of a control device according to a third embodiment. FIG. 9 is a block diagram showing an example of control of a control device according to the third embodiment. FIG. 10 is a first diagram showing the configuration of a magnetic geared motor according to a fourth embodiment. FIG. 11 is a second diagram showing the configuration of a magnetic geared motor according to the fourth embodiment. FIG. 12 is a diagram showing the effect of the magnetic geared motor according to the fourth embodiment. FIG. 13 is a third diagram showing the configuration of a magnetic geared motor according to the fourth embodiment.

[0017] First Embodiment Hereinafter, an embodiment will be described in detail with reference to the drawings.

[0018] (Overall Configuration of Mobile Body) Fig. 1 is a diagram showing the overall configuration of a mobile body according to the first embodiment. The mobile body 1 is, for example, a ship. In other embodiments, the mobile body 1 may be an airplane, an automobile, a railroad vehicle, or the like. As shown in Fig. 1, the mobile body 1 includes a main body 3, a propulsion system 4, a steering system 5, an operation unit 10, and a control device 2.

[0019] The main body 3 is the body (hull, aircraft body, vehicle body) of the mobile object 1. In addition, a plurality of sensors 31 are provided in each part of the main body 3. Each sensor 31 measures the speed, attitude angle (roll angle, pitch angle, yaw angle), acceleration (up-down direction, left-right direction, front-rear acceleration), etc. of the mobile object 1 (main body 3).

[0020] The propulsion system 4 is a mechanism that applies thrust to the moving body 1 (main body 3). The propulsion system 4 has an inverter control device 40, an inverter 41, a magnetic geared motor 42, a rotating shaft 43, a thruster 44, a current sensor 45, and a rotation angle sensor 46.

[0021] The inverter 41 supplies power to the magnetic geared motor 42 in accordance with commands (voltage and current commands) from the inverter control device 40 .

[0022] The magnetic geared motor 42 has a magnetic gear unit 42A consisting of a high-speed rotor HSR and a low-speed rotor PPR. When current supplied from the inverter 41 flows through a stator winding (not shown), the high-speed rotor HSR rotates due to the magnetomotive force of the winding. Electric torque (motor torque) applied to the high-speed rotor HSR is transmitted to the low-speed rotor PPR via a magnetic spring. As a result, the low-speed rotor PPR rotates in synchronization with the high-speed rotor HSR at a predetermined reduction ratio.

[0023] The rotating shaft 43 is the output shaft of the magnetic geared motor 42 and connects the low-speed rotor PPR and the propeller 44 via a joint JT.

[0024] The propulsion device 44 is rotationally driven by the torque transmitted from the magnetic geared motor 42, and applies thrust to the moving body 1 (main body 3). The propulsion device 44 is, for example, a propeller. In other embodiments, the propulsion device 44 may be a wheel of an automobile or a railroad vehicle.

[0025] A current sensor 45 is provided on the power line connecting the inverter 41 and the magnetic geared motor 42. The current sensor 45 measures the current (motor current) supplied from the inverter 41 to the magnetic geared motor 42. The magnetic geared motor 42 is also provided with a rotation angle sensor 46. The rotation angle sensor 46 includes a high-speed rotation angle sensor 46A that measures the rotation angle and rotation speed of the high-speed rotor HSR, and a low-speed rotation angle sensor 46B that measures the rotation angle and rotation speed of the low-speed rotor PPR (rotating shaft 43).

[0026] The inverter control device 40 feedback controls the voltage and current applied by the inverter 41 to the magnetic geared motor 42 based on measurement data such as the motor current and the rotation speed of the rotating shaft 43 so that the torque of the magnetic geared motor 42 matches the torque command requested by the control device 2 described later.

[0027] The steering system 5 has a steering mechanism 51 that can change the direction of travel of the moving body 1 (main body 3).

[0028] The operation unit 10 accepts inputs such as operation commands from an operator.

[0029] The control device 2 controls the propulsion system 4 and the steering system 5 based on operation commands from the operator. In this embodiment, the control device 2 particularly monitors the state of the mobile body 1 and meteorological and sea conditions, and adjusts the torque of the magnetic geared motor 42 of the propulsion system 4 so as to prevent loss of synchronization of the magnetic geared motor 42. Note that the control of the steering system 5 (such as the calculation of the rudder angle command) is similar to that of conventional technology, and therefore a detailed description thereof will be omitted.

[0030] (Functional Configuration of Control Device) Fig. 2 is a block diagram showing the functional configuration of the control device 2. As shown in Fig. 2, the control device 2 includes a processor 20, a memory 21, a storage 22, and a communication interface 23.

[0031] The processor 20 operates in accordance with a predetermined program to function as a control unit 201 , a switching unit 202 , a manual setting unit 203 , an automatic setting unit 204 , an estimation unit 205 , and a limiter 206 .

[0032] The control unit 201 performs feedback control to adjust the electric torque (motor torque) of the magnetic geared motor 42 based on the difference between the measurement data of the rotation speed of the propeller 44 (rotating shaft 43) and the rotation speed command.

[0033] The switching unit 202 switches between setting modes for a torque limit value that limits the electric torque of the magnetic geared motor 42. The setting modes include a manual mode in which the operator manually sets the torque limit value, and an auto mode in which the torque limit value is automatically set.

[0034] When the manual mode is selected, the manual setting unit 203 sets the torque limit value to a value designated by the operator.

[0035] When switched to auto mode, the automatic setting unit 204 sets a torque limit value based on at least one of the load torque transmitted from the propulsion unit 44 to the magnetic geared motor 42 and measurement data representing the state of the moving body 1.

[0036] The estimation unit 205 estimates the load torque based on state variables including measurement data representing the state of the moving body 1 .

[0037] The limiter 206 outputs a final torque command to the inverter control device 40 , which is obtained by limiting the torque limit value calculated by the control unit 201 with the torque limit value set by the manual setting unit 203 or the automatic setting unit 204 .

[0038] The predetermined program executed by the processor 20 is stored on a computer-readable recording medium. Computer-readable recording media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories. The computer program may be distributed to a computer via a communication line, and the computer that receives the distribution may execute the program. The program may also be a program for implementing some of the above-described functions. Furthermore, the program may be a so-called differential file (differential program) that can realize the above-described functions in combination with a program already stored in the computer system.

[0039] The memory 21 has a memory area necessary for the operation of the processor 20 .

[0040] The storage 22 is a so-called auxiliary storage device, such as a hard disk drive (HDD), a solid state drive (SSD), etc. The storage 22 stores data that each part of the processor 20 acquires, generates, and references during processing.

[0041] The communication interface 23 transmits and receives signals (operation commands, measurement data, etc.) to and from each device.

[0042] (Processing of the control device) Next, details of the processing of the control device 2 will be described. The control device 2 according to this embodiment reduces the torsional torque generated in the magnetic gear portion 42A instead of increasing the maximum transmission torque of the magnetic geared motor 42. By reducing the torsional torque, step-out is suppressed without increasing the size of the magnetic geared motor 42, etc.

[0043] Fig. 3 is a schematic diagram of the magnetic gear unit according to the first embodiment. When the magnetic gear unit 42A is represented by a simplified model as shown in Fig. 3, the torsional torque generated in the magnetic gear unit 42A can be reduced by controlling the electric torque generated by applying current to the stator winding (not shown) of the magnetic geared motor 42 or the torque of the propeller 44 in accordance with the load torque. From Fig. 4, the following equations (1) to (4) hold true.

[0044]

[0045]

[0046]

[0047]

[0048] θ in Equation (1) ｅ is the torsion angle (electrical angle) that indicates the difference in rotation angle between the high-speed rotor HSR and the low-speed rotor PPR, and ω ｅ is the torsional angular velocity (electrical angle) that indicates the rotational speed difference. ｅ , ω ｅ is obtained from equation (2). p in equation (2) ｈ , θ ０ , ω ０ are the number of pole pairs, rotation angle (mechanical angle), and angular velocity (mechanical angle) of the high-speed rotor HSR, respectively. ｓ , θ １ , ω １ are the number of pole pieces of the low-speed rotor PPR, the rotation angle (mechanical angle), and the angular speed (mechanical angle) in degrees, respectively.

[0049] The second term on the right side of equation (3) is the torque (magnetic spring torque) of the magnetic gear portion 42A, and its maximum value is the maximum transmission torque T ｍａｘ J in equation (3) ｒ , T ｒ is obtained from equation (4). ０ is the moment of inertia of the high-speed rotor HSR, J １ is the moment of inertia of the slow rotor PPR, T ０ is the electrical torque, T １ is the load torque. Therefore, the first term T on the right side of equation (3) ｒ is the maximum transmission torque Tｍａｘ If this is exceeded, the stable operating point disappears and step-out occurs.

[0050] Ignoring losses, in a steady state, the first and second terms on the right side of equation (3) are balanced, and the left side is 0, i.e., the rotational speed difference is 0, and the high-speed rotor HSR and the low-speed rotor PPR rotate in perfect synchronization. From this state, the load torque T １ is ΔT １ When it increases, T ｒ increases, the balance of equation (3) is lost, the left side becomes ≠ 0, and the rotation angle difference θ ｅ At this time, if the load torque T １ At the same time as the change in the electric torque T ０ is expressed as ΔT ０ Let's say we change only

[0051]

[0052] Then, T ｒ The change in the maximum transmission torque T ｍａｘ Therefore, step-out can be suppressed without increasing the number of magnets to provide a margin for maximum transmission torque.

[0053] However, in reality, it is not possible to know exactly when and what kind of load will act, and it is not possible to control the electric torque with zero delay.

[0054] A simple and reliable method is to reduce (or limit) the electric torque before an overload occurs. However, if the electric torque is always reduced (limited), the output torque of the magnetic geared motor 42 will decrease, and it will take time for the moving body 1 to move (navigate). For this reason, the amount of reduction (limitation) of the electric torque and its duration must be appropriately adjusted.

[0055] Therefore, the control device 2 according to this embodiment executes a process of limiting the electric torque in the manual setting unit 203 or the automatic setting unit 204 .

[0056] 4 is a block diagram showing an example of control by the control device according to the first embodiment. Details of the control process by the control device 2 will be described with reference to FIG.

[0057] First, as shown in FIG. 4, the switching unit 202 switches the setting mode between the manual mode and the auto mode.

[0058] 5 is a diagram illustrating the function of the switching unit 202 according to the first embodiment. For example, as shown in FIG. 5, the switching unit 202 switches the setting mode to the manual mode when any one of conditions M1 to M3 is satisfied. Furthermore, the switching unit 202 switches the setting mode to the auto mode when all of conditions A1 to A3 are satisfied.

[0059] The setting mode switching conditions M1 to M3, A1 to A3 are as follows: (M1) When the operator performs an operation to select manual mode via the operation unit 10. (M2) When the reliability of the measurement data is insufficient. (M3) When the environmental conditions are predicted to be poor. (A1) When the operator performs an operation to select auto mode via the operation unit 10. (A2) When the reliability of the measurement data is sufficient. (A3) When the environmental conditions are predicted to be good.

[0060] Regarding conditions M1 and A1, the operator switches the setting mode depending on, for example, the operation plan of the mobile body 1. For example, if it is known in advance that severe driving such as crash astern or sharp turns will be performed during a sea trial (i.e., an overload will be generated on the magnetic geared motor 42), the operator selects the manual mode (condition M1). On the other hand, if it is known in advance that such severe driving will not be performed, the operator selects the auto mode (condition A1).

[0061] The measurement data for conditions M2 and A2 are measurement data of the rotation speed of the propulsion unit 44 (rotation shaft 43) used by the automatic setting unit 204 to set the torque limit value, and measurement data such as the speed, attitude angle, and acceleration of the mobile body 1 (main body 3) measured by the sensor 31. For example, if any of the sensors fails or a data transmission error occurs, the reliability of the measurement data is determined to be insufficient (condition M2). On the other hand, if all the sensors are operating normally or no data transmission error occurs, the reliability of the measurement data is determined to be sufficient (condition A2).

[0062] The environmental conditions of conditions M3 and A3 include information indicating whether meteorological conditions such as wind and rain and oceanographic conditions such as waves are good or bad. The control device 2 acquires the current and future environmental conditions (good / bad) along the travel route of the mobile object 1 from the operation unit 10 or an external server (not shown). The environmental conditions may include predicted values ​​such as wind speed, rainfall, and wave height, and the switching unit 202 may determine whether the environmental conditions are good or bad based on whether any of these predicted values ​​exceed a threshold.

[0063] In other words, the manual mode is a mode that is set when it is difficult for the estimating unit 205 to estimate the load torque, such as in stormy weather, and the judgment of an experienced operator is important. The auto mode is a mode that is set when the weather and sea conditions are calm, such as in fine weather, and the load torque can be estimated relatively accurately. In order to minimize the travel time (navigation time) of the mobile unit 1 and maximize fuel efficiency, it is necessary to finely adjust the torque limit value. Therefore, when conditions A2 and A3 are satisfied, it is desirable to set the auto mode and adjust the torque limit value according to the state of the mobile unit 1, etc.

[0064] When the setting mode is the manual mode, the manual setting unit 203 sets the value input by the operator via the operation unit 10 as the torque limit value.

[0065] Fig. 6 is a block diagram showing an example of processing in auto mode according to the first embodiment. When the setting mode is auto mode, the automatic setting unit 204 sets the torque limit value according to the torque determination logic shown in Fig. 6. In auto mode, attention is focused on factors that increase the load torque, and the states of these factors are determined from measurement data measured by sensors, operation commands, etc.

[0066] The automatic setting unit 204 determines the first torque limit value corresponding to the state (measurement data) of the mobile body 1 by referring to first limit value information D1, which defines a predetermined relationship between measurement data indicating the state of the mobile body 1 and the torque limit value. The measurement data indicating the state of the mobile body is, for example, the attitude angle of the main body 3 of the mobile body 1 measured by the sensor 31. If the mobile body 1 is a ship, the hull motion (pitching) may increase in rough weather, causing the propeller 44 (propeller) mounted at the rear of the hull to temporarily be exposed above the water surface and spin (propeller racing). In this case, the load torque varies greatly depending on whether the propeller is exposed or not, which could cause the magnetic geared motor 42 to lose synchronization.

[0067] In this way, when it is known that a specific state of the moving body 1 affects fluctuations in the load torque, first limit value information D1 is prepared, which defines the relationship between the specific state of the moving body 1 (the pitch angle in the above example) and the torque limit value, which is the maximum electric torque that does not cause step-out (the electric torque that becomes the step-out limit). The first limit value information D1 may be a table created based on a database of simulations, model tests, actual measurement data of the moving body 1 itself or other similar moving bodies, or it may be a mathematical model constructed based on a database. The automatic setting unit 204 uses the first limit value information D1 to determine the first torque limit value corresponding to the pitch angle of the main body 3, which changes from moment to moment.

[0068] Furthermore, the model of the magnetic gear unit 42A in FIG. 3 shows that step-out can occur not only due to a sudden change in load torque but also due to a sudden change in electric torque. For example, a crash astern operation can cause a sudden change in electric torque, resulting in step-out. In other words, operation commands related to maneuvering (such as rotation speed commands to the propulsion system 4 and rudder angle commands to the steering system 5) and actual values ​​(measurement data on the rotation speed, attitude, and acceleration of the low-speed rotor PPR) are also considered effective in determining the torque limit value. Therefore, the first limit value information D1 may define the relationship between these operation commands and actual values ​​and the torque limit value.

[0069] Furthermore, the automatic setting unit 204 may set the torque limit value based on the load torque estimated from various states of the moving body 1 and operation commands. First, the estimation unit 205 estimates the load torque, for example, as follows. With reference to the schematic diagram of the magnetic gear unit 42A in FIG. 3 and the above equations (1) to (4), the propulsion system 4 driven by the magnetic geared motor 42 is modeled as follows. Here, an extremely simplified model is used for ease of understanding. Also, it is assumed here that the moving body 1 is a ship and the propeller 44 is a propeller.

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078] Q in equations (6) to (9) ｍｏｔｏｒ０ is the electrical torque of the magnetic geared motor 42, Q ｍｏｔｏｒ１ is the output torque of the magnetic geared motor (magnetic spring torque), Q ｐ is the load torque (propeller torque), τ ｅis the response time constant of the electric torque, Q ｍｏｔｏｒ０ ＊ is the command value of the electric torque (torque command). ｐ is a linear function of the inflow velocity of the propeller with respect to time t, and can be expressed as homogeneous differential equations as equations (11) to (12). From these equations, the load torque Qp is expressed as a model in equation (13). Note that C in equation (13) １ , C ２ , C ３ is a coefficient determined by the propeller characteristics.

[0079] Also, the state variable x of the moving object 1 is set as shown in equation (14).

[0080]

[0081] Using the state variable x^ estimated every moment by a method to be described later, the load torque is estimated as shown in equation (15).

[0082]

[0083] To construct the estimation algorithm, the state equation is given by equation (16).

[0084]

[0085] The state equation of the continuous system shown in equation (16) above is discretized with a calculation period ΔT. For example, when it is approximated by the forward Euler method, the state equation of the discrete system shown in equation (17) below is obtained.

[0086]

[0087] Here, k is the calculation step. Next, the observable (measurable) signals are defined. For example, if only the angular velocities of the high-speed rotor HSR and the low-speed rotor PPR can be measured, the observation equation is given by the following equation (18). H is a function that converts state variables into observation variables.

[0088]

[0089] The state variables are estimated using the state equation of equation (17) and the observation equation of equation (18). For example, in this embodiment, the state variables are estimated using an unscented Kalman filter (UKF). Note that in other embodiments, other methods may be used to estimate the state variables. State estimation using the unscented Kalman filter involves three steps: "1. Sigma point calculation step," "2. Prediction step," and "3. Update step." These steps will be explained in order below.

[0090] 1. Sigma point calculation step Sigma points are calculated using state variables. In the first calculation step, state variables with initial values ​​are used. If the dimension of the state variables is n, 2n+1 sigma points are set for each state variable. In this example, n=6. A state variable (for example, x) at a certain calculation point k is calculated. １ The method for setting the sigma point is shown below for the sigma point [k]. To make the formula easier to read, the symbol [k] indicating the calculation point is omitted.

[0091] The weighting coefficient W for calculating the average value of the sigma points is calculated using the following equations (19) to (22). α, β, and κ are parameters, and it is generally considered best to set them as 0≦α≦1, κ=3−n, and β=2. α is a parameter that adjusts the dispersion of the sigma points (distance from the average value), and the larger the parameter, the greater the dispersion.

[0092]

[0093]

[0094]

[0095]

[0096] As shown in equations (23) and (24), one of the sigma points (X ０ ) is the weighted mean value μ.

[0097]

[0098]

[0099] The remaining 2n sigma points are calculated using the average value μ calculated above and the following equations (25) to (27).

[0100]

[0101]

[0102]

[0103] Taking all state variables into consideration, the set of sigma points can be expressed as a matrix as shown in the following equation (28): As described above, n=6 in this example.

[0104]

[0105] Element X of formula (28) ｉ，ｊ The subscript i=0, . . . , 2n is the number of the sigma point, and j=1, .

[0106] 2. Prediction step: Unscented transformation of the sigma points is performed using the following formula (29). The set after transformation can be expressed as a matrix as formula (30).

[0107]

[0108]

[0109] X and Y are (2n+1) × n matrices. The mean value x and covariance matrix P are calculated using the following equations (31) to (34).

[0110]

[0111]

[0112]

[0113]

[0114] Q in equation (34) is a model of process noise.

[0115] 3. Update step: The sigma points are transferred to the observation space using the observation equation.

[0116]

[0117] The subscript i = 0, ..., 2n in equation (35) is the number of the sigma point, j = 1, ..., n is the number of the state variable, and k = 1, ..., l is the number of the observation point. l is the number of observation points. Also, from equations (36) to (38), the average value μ of the sigma points transferred to the observation space is Ｚ and the covariance matrix P Ｚ In equation (38), R is an l × l matrix, which is a model (covariance matrix) of the observation noise.

[0118]

[0119]

[0120]

[0121] In equations (35) to (38), the subscript i = 0, ..., 2n is the number of the sigma point, j = 1, ..., n is the number of the state variable, and k = 1, ..., l is the number of the observation point. Also, l is the number of the observation points.

[0122] Furthermore, the observed value z = [ω ０，ｍｅａｓ ω １，ｍｅａｓ ] Ｔ Calculate the residual y of

[0123]

[0124] Next, the Kalman gain K is calculated using the following equations (40) and (41).

[0125]

[0126]

[0127] Using the calculated Kalman gain, the estimated values ​​of the state variables are updated using the following equation (42).

[0128]

[0129] Furthermore, the calculated Kalman gain is used to update the covariance matrix using the following equation (43).

[0130]

[0131] The estimation unit 205 repeatedly performs the above-mentioned "2. prediction step" and "3. update step." That is, in the prediction step, the state estimated value X ｋ－１ From the above, the prior distribution X of the state at the current time k is ｋ In addition, in the update step, the predicted prior distribution X ｔ The residual y of the value z transferred to the observation space is calculated, and the posterior distribution X̂ ｋ +Ky. The estimation unit 205 obtains the estimated value x^ of the state variable in this way, and calculates the estimated value Qp^ of the load torque every moment using the above equation (15).

[0132] Next, the automatic setting unit 204 determines the second torque limit value based on the load torque estimate Qp^ at the current time. For example, the automatic setting unit 204 prepares second limit value information D2 that defines the relationship between the load torque and the torque limit value, which is the maximum electric torque that does not cause step-out (the electric torque that is the step-out limit). The second limit value information D2 may be a table created based on a database of data such as simulations, model tests, and actual measurement data of the mobile body 1 itself or other similar mobile bodies, or it may be a mathematical model constructed based on a database. The automatic setting unit 204 determines the second torque limit value corresponding to the estimated load torque based on the second limit value information D2.

[0133] Furthermore, the automatic setting unit 204 selects the smaller of the first torque limit value and the second torque limit value using the selector 204A, and sets this as the final torque limit value.

[0134] For example, if the torque limit value suddenly increases, the electric torque may become excessive, which may cause step-out. Therefore, if the torque limit value selected by the selector 204A is higher than the previous value (is on the higher side), the automatic setting unit 204 uses the rate limiting unit 204B to limit the amount or rate of change of the torque limit value over time.

[0135] The automatic setting unit 204 repeatedly performs the process shown in FIG. 6 from time to time to set an appropriate torque limit value according to the state of the moving body 1.

[0136] Returning to FIG. 4, the control unit 201 calculates a torque command for the magnetic geared motor 42 based on the difference between the measurement data of the rotation speed of the propeller 44 and the rotation speed command issued from the operation unit 10 .

[0137] Furthermore, limiter 206 determines a final torque command by limiting the torque limit value calculated by control unit 201 with the torque limit value. In manual mode, the torque limit value set by manual setting unit 203 is given to limiter 206, and in auto mode, the torque limit value set by automatic setting unit 204 is given to limiter 206. The final torque command is output to inverter control device 40. Inverter control device 40 adjusts the voltage and current of inverter 41 so that the electric torque of magnetic geared motor 42 matches the final torque command.

[0138] The control device 2 repeatedly executes the processes shown in FIGS. 4 and 6 while the moving body 1 is in operation.

[0139] In the above example, for simplicity, the load model was estimated only considering a model representing a state in which the propeller is completely submerged. In reality, a large load torque acts from the propeller when it is exposed above the water surface (propeller racing) and then submerged again. Such movements are considered to be closely correlated with hull motion, such as the inclination and heave of the hull. Therefore, the estimator 205 may estimate the load torque by adding measurement data related to the hull motion (such as attitude angle and acceleration) to the above-described state equation (17) and observation equation (18). Furthermore, propeller-related load fluctuations can occur not only when propeller racing, but also when the rudder is turned to make a sharp turn. In other words, maneuvering commands (such as rotation speed commands to the propulsion system 4 and rudder angle commands to the steering system 5) and actual values ​​(measurement data on the rotation speed, attitude, and acceleration of the low-speed rotor PPR) are also considered effective in determining the torque limit value. Therefore, the estimation unit 205 may estimate the load torque by adding these operation commands and actual values ​​to the above-described state equation (17) and observation equation (18), thereby improving the estimation accuracy of the load torque.

[0140] 6 shows an example in which the automatic setting unit 204 selects the smaller of the first torque limit value and the second torque limit value using the selector 204A, but this is not limiting. In other embodiments, the automatic setting unit 204 may determine only the first torque limit value or only the second torque limit value as the torque limit value. In this case, the selector 204A is omitted.

[0141] (Actions and Effects) As described above, the control device 2 of the moving body 1 according to this embodiment includes a switching unit 202 that switches between a manual mode in which the operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor 42, and an auto mode in which the torque limit value is automatically set, a manual setting unit 203 that sets the torque limit value to a value specified by the operator when switched to the manual mode, and an automatic setting unit 204 that sets the torque limit value according to the load torque transmitted from the propulsion unit 44 to the magnetic geared motor 42 or the state of the moving body 1 when switched to the auto mode.

[0142] In this way, in manual mode, the control device 2 allows the operator to adjust the torque limit value according to the situation and suppress step-out of the magnetic geared motor 42. On the other hand, in auto mode, the control device 2 can operate the magnetic geared motor 42 at maximum efficiency while suppressing step-out by finely adjusting the electric torque according to the load torque and the state of the mobile object 1. Therefore, it is possible to minimize the travel time of the mobile object 1 and maximize fuel efficiency.

[0143] In addition, the automatic setting unit 204 refers to first limit value information D1 that predetermines the relationship between the state of the moving body 1 and the torque limit value, and sets the first torque limit value according to the state of the moving body 1 as the torque limit value.

[0144] For example, if the mobile body 1 is a ship and propeller racing occurs due to a change in the state (tilt) of the hull, there is a possibility that the load torque applied to the magnetic geared motor 42 will fluctuate significantly. By setting the torque limit value in accordance with the state of the mobile body 1 as described above, the control device 2 can appropriately adjust the electric torque in accordance with the fluctuation in the load torque that accompanies a change in the state of the mobile body 1, thereby suppressing loss of synchronization.

[0145] The control device 2 further includes an estimation unit 205 that estimates the load torque based on state variables including measurement data that represent the state of the mobile object 1. The automatic setting unit 204 references second limit value information D2 that defines a predetermined relationship between the load torque and the torque limit value, and sets the second torque limit value according to the estimated load torque as the torque limit value.

[0146] In this way, the control device 2 can estimate the load torque acting on the magnetic geared motor 42 from moment to moment, and appropriately adjust the electric torque in accordance with fluctuations in the load torque, thereby suppressing loss of synchronization.

[0147] Furthermore, the automatic setting unit 204 determines a first torque limit value and a second torque limit value, and sets the smaller of these values ​​as the torque limit value.

[0148] For example, when the moving body 1 is not tilted and propeller racing is not occurring, the moving body 1 is in a stable state, and therefore the first torque limit value may be a value that relaxes the limit on the electric torque. On the other hand, when the load torque increases due to acceleration or turning of the moving body 1, the second torque limit value may be a value that further restricts the electric torque. Even in such a case, the control device 2 can adjust the electric torque to the safe side by setting the smaller value as the final torque limit value. This makes it possible to more reliably suppress loss of synchronization.

[0149] Second Embodiment Next, a second embodiment will be described with reference to Fig. 7. Components common to the above-described embodiment will be assigned the same reference numerals, and detailed description thereof will be omitted.

[0150] In the first embodiment, in the auto mode, the estimation unit 205 of the control device 2 obtains the estimated value Qp^ of the current load torque. In contrast, the estimation unit 205 according to the present embodiment uses a model M to predict the behavior of the load torque and electric torque (motor torque) in the future a predetermined number of steps ahead.

[0151] FIG. 7 is a block diagram illustrating an example of processing in auto mode according to the second embodiment. Specifically, as shown in FIG. 7 , the estimation unit 205 performs processing to estimate future load torque and electric torque using model M, instead of the processing of the first embodiment ( FIG. 6 ). Model M receives measurement data from several past steps as input x and outputs estimated values ​​y of future load torque and electric torque. The measurement data includes measurement data such as the attitude angle and acceleration representing the inclination and sway of the mobile object 1 (main body 3), and the rotation angle and rotation speed of each rotor. Model M may be, for example, an autoregressive (AR) model such as a radial base function (RBF)-ARX model. In another embodiment, model M may be a learning model learned from past measurement data.

[0152] Furthermore, instead of the processing of the first embodiment ( FIG. 6 ), the automatic setting unit 204 performs processing to set a torque limit value based on the predicted future load torque and electric torque so as to limit the current electric torque for a certain period of time. For example, as shown in FIG. 7 , the automatic setting unit 204 performs a simulation of a step-out using the predicted future load torque and electric torque as input, and when a step-out is predicted to occur in the future, determines a torque limit value (second torque limit value) based on the estimated load torque and second limit value information D2. The method for determining the second torque limit value is the same as in the first embodiment. Furthermore, as in the first embodiment, the automatic setting unit 204 may limit the amount or rate of change of the torque limit value per time using the rate limiting unit 204B only when the torque limit value is increased.

[0153] The subsequent processing of the control device 2 is the same as in the first embodiment. That is, the control unit 201 outputs a final torque command, which is the calculated torque command limited by the torque limit value set by the automatic setting unit 204, to the inverter control device 40. The inverter control device 40 adjusts the voltage and current of the inverter 41 so that the electric torque of the magnetic geared motor 42 matches the final torque command.

[0154] In this way, the control device 2 according to this embodiment limits the electric torque in advance when a loss of synchronism is predicted in the future, thereby enabling the control device 2 to more reliably prevent loss of synchronism of the magnetic geared motor 42.

[0155] Third Embodiment Next, a third embodiment will be described with reference to Figures 8 and 9. Components common to the above-described embodiments are given the same reference numerals, and detailed description thereof will be omitted.

[0156] Fig. 8 is a block diagram showing the functional configuration of a control device according to the third embodiment. Fig. 9 is a block diagram showing a control example of the control device according to the third embodiment. In the above-described embodiment, an example has been described in which the control device 2 limits the electric torque (motor torque) of the magnetic geared motor 42 to suppress step-out of the magnetic geared motor 42. In contrast, the control device 2 according to this embodiment suppresses step-out of the magnetic geared motor 42 by controlling the load torque by limiting at least one of the rudder angle of the steering system 5 and the rotation speed of the propeller 44.

[0157] Specifically, as shown in Figures 8 and 9, the control device 2 according to this embodiment further includes a limit value calculation unit 207. The limit value calculation unit 207 calculates a rotation speed limit value and a steering angle limit value that limit a rotation speed command and a steering angle command, based on the torque limit value set by the manual setting unit 203 or the automatic setting unit 204. The limit value calculation unit 207 may also calculate the rotation speed limit value and the steering angle limit value by further using the load torque estimate value estimated by the estimating unit 205 according to the first or second embodiment, or the future load torque and electric torque estimate value estimated by the estimating unit 205 according to the second embodiment.

[0158] 9 , the limiter 206 has a first limiter 206A and a second limiter 206B. The first limiter 206A limits the rudder angle command specified by the operation unit 10 with a rudder angle limit value calculated by a limit value calculation unit 207. The final rudder angle command corrected by the first limiter 206A is output to the steering gear 51. The second limiter 206B limits the rotation speed command specified by the operation unit 10 with the rotation speed limit value calculated by the limit value calculation unit 207. The final rotation speed command corrected by the second limiter 206B is output to the control unit 201. The control unit 201 performs feedback control based on the difference between the final rotation speed command and the rotation speed of the propeller 44, and generates a torque command to be output to the inverter control device 40.

[0159] Note that, although the example in FIG. 9 shows an example in which the limit value calculation unit 207 calculates both the rotation speed limit value and the steering angle limit value, this is not limiting. In other embodiments, the limit value calculation unit 207 may calculate only the rotation speed limit value. In this case, the first limiter 206A may be omitted. Furthermore, in still other embodiments, the limit value calculation unit 207 may calculate only the steering angle limit value. In this case, the second limiter 206B may be omitted.

[0160] In order to prevent the magnetic geared motor 42 from losing synchronization, it is effective to limit not only the electric torque (motor torque) but also the load torque. Therefore, as described above, the control device 2 according to this embodiment limits the load torque by limiting the rudder angle of the steering system 5 and the rotation speed of the propeller 44, instead of the electric torque of the magnetic geared motor 42. For example, if the mobile body 1 is a ship, when propeller racing or the like occurs, the rotation speed command for the propeller (propeller 44) can be forcibly reduced, thereby reducing the load torque acting from the propeller on the magnetic geared motor 42 when the propeller is submerged again. Therefore, it is possible to more reliably avoid loss of synchronization.

[0161] Fourth Embodiment Next, a fourth embodiment will be described with reference to Figures 10 to 13. Components common to the above-described embodiments are given the same reference numerals, and detailed description thereof will be omitted.

[0162] 10 is a first diagram showing the configuration of a magnetic geared motor according to a fourth embodiment. As shown in FIG. 10, the magnetic geared motor 42 may further include a torque limiting mechanism 42B provided between the magnetic geared motor 42 and a propeller 44.

[0163] The torque limiting mechanism 42B is a so-called torque limiter, and is, for example, a torque limiter that uses frictional force (such as a clutch) or a torque limiter that uses spring restoring force. The torque limiting mechanism 42B transmits torque while causing slip between the low-speed rotor PPR and the propeller 44. In other words, the torque limiting mechanism 42B limits the torque transmitted between the low-speed rotor PPR and the propeller 44 so as not to exceed the maximum transmission torque of the magnetic gear unit 42A.

[0164] Fig. 11 is a second diagram showing the configuration of a magnetic geared motor according to a fourth embodiment. As shown in Fig. 11, the joint JT connecting the rotary shaft 43 and the thruster 44 may be an elastic joint. The rigidity of the elastic joint JT is set lower than the magnetic torsional rigidity of the magnetic geared motor 42. By providing the elastic joint JT with damping against shaft torsion, changes in the load torque input to the low-speed rotor PPR of the magnetic geared motor 42 can be buffered, and loss of synchronization can be more reliably suppressed.

[0165] FIG. 12 illustrates the effects of the magnetic geared motor according to the fourth embodiment. The graph in FIG. 12 shows simulation results for an overload (a load torque 120% of the maximum transmission torque). For example, the maximum transmission torque is 1 pu. Case 0 represents the simulation results for a configuration without either the torque limiting mechanism 42B or the elastic coupling JT (prior art). Case 1 represents the simulation results for a configuration with the torque limiting mechanism 42B of FIG. 10 . Case 2 represents the simulation results for a configuration with the torque limiting mechanism 42B and the elastic coupling JT of FIG. 11 . The upper graph in Case 0 shows that an overload occurs at a certain time, and the load torque is directly input to the low-speed rotor PPR. As a result, as shown in the middle graph in Case 0, the rotational speeds of the high-speed rotor and the low-speed rotor become unsynchronized, resulting in a loss of synchronization. Furthermore, the lower graph in Case 0 shows that an alternating torque is generated due to the loss of synchronization. On the other hand, in both Case 1 and Case 2, as shown in the upper graph, the load torque input to the low-speed rotor PPR is limited by the torque limiting mechanism 42B and the elastic coupling JT. This causes slippage between the low-speed rotor PPR and the propeller 44, so as shown in the middle graph, the rotational speeds of the high-speed rotor HSR and the low-speed rotor PPR do not deviate significantly as in Case 0, and a synchronized state can be maintained. In other words, loss of synchronization was suppressed in Case 1 and Case 2. Furthermore, as shown in the lower graphs for Case 1 and Case 2, fluctuations in the magnetic spring torque were significantly suppressed compared to Case 0.

[0166] FIG. 13 is a third diagram showing the configuration of a magnetic geared motor according to a fourth embodiment. The magnetic geared motor 42 may include a flywheel 42C instead of or in addition to the torque limiting mechanism 42B. FIG. 13 shows an example in which the magnetic geared motor 42 includes both the torque limiting mechanism 42B and the flywheel 42C. The flywheel 42C, together with the elastic couplings JT1 and JT2 located on both sides, constitutes a tuned mass damper (TMD). This allows the flywheel 42C to provide appropriate damping to the torsion angle fluctuations of the low-speed rotor PPR and the high-speed rotor HSR, thereby more reliably suppressing loss of synchronization.

[0167] Other Embodiments Although the embodiments have been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel.

[0168] <Additional Notes> The mobile body control device, mobile body, mobile body control method, and program described in the above-described embodiments can be understood, for example, as follows.

[0169] (1) According to a first aspect, the control device 2 of the moving body 1 is a control device 2 of the moving body 1 having a propeller 44 that is rotationally driven by a magnetic geared motor 42, and includes: a switching unit 202 that switches between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor 42, and an auto mode in which the torque limit value is automatically set; a manual setting unit 203 that sets the torque limit value to a value specified by the operator when switched to the manual mode; an automatic setting unit 204 that sets the torque limit value based on at least one of the load torque transmitted from the propeller 33 to the magnetic geared motor 42 and measurement data representing the state of the moving body 1 when switched to the auto mode; and a limiter 206 that limits, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor 42 based on the difference between a rotation speed command that specifies the rotation speed of the propeller 44 and the measurement data for the rotation speed of the propeller 44.

[0170] In this way, in manual mode, the control device 2 allows the operator to adjust the torque limit value according to the situation and suppress step-out of the magnetic geared motor 42. On the other hand, in auto mode, the control device 2 can operate the magnetic geared motor 42 at maximum efficiency while suppressing step-out by finely adjusting the electric torque according to the load torque and the state of the mobile object 1. Therefore, it is possible to minimize the travel time of the mobile object 1 and maximize fuel efficiency.

[0171] (2) According to the second aspect, in the control device 2 of the moving body 1 relating to the first aspect, the automatic setting unit 204 refers to first limit value information D1 that predetermines the relationship between the state of the moving body 1 and the torque limit value, and sets the first torque limit value corresponding to the state of the moving body 1 as the torque limit value.

[0172] By setting the torque limit value in this manner in accordance with the state of the moving body 1, the control device 2 can appropriately adjust the electric torque in accordance with fluctuations in the load torque that accompany changes in the state of the moving body 1, thereby suppressing loss of synchronization.

[0173] (3) According to the third aspect, the control device 2 of the mobile body 1 relating to the first aspect further includes an estimation unit 205 that estimates the load torque based on state variables including measurement data representing the state of the mobile body 1, and the automatic setting unit 204 sets the second torque limit value corresponding to the estimated load torque as the torque limit value by referring to second limit value information D2 that predetermines the relationship between the load torque and the torque limit value.

[0174] In this way, the control device 2 can estimate the load torque acting on the magnetic geared motor 42 from moment to moment, and appropriately adjust the electric torque in accordance with fluctuations in the load torque, thereby suppressing loss of synchronization.

[0175] (4) According to the fourth aspect, the control device 2 of the mobile body 1 relating to the first aspect further includes an estimation unit 205 that estimates the load torque based on state variables including measurement data representing the state of the mobile body 1, and the automatic setting unit 204 determines a first torque limit value according to the state of the mobile body 1 by referring to first limit value information D1 that predetermines the relationship between the state of the mobile body 1 and the torque limit value, determines a second torque limit value according to the estimated load torque by referring to second limit value information D2 that predetermines the relationship between the load torque and the torque limit value, and sets the smaller of the first torque limit value and the second torque limit value as the torque limit value.

[0176] For example, even when the state of the mobile object 1 is stable, the load torque may actually be increasing depending on the operating state of the mobile object 1. Even in such a case, the control device 2 can adjust the electric torque to the safe side by comparing the first torque limit value determined based on the state of the mobile object with the second torque limit value determined based on the estimated load torque and selecting a final torque limit value. This makes it possible to more reliably suppress step-out.

[0177] (5) According to the fifth aspect, in the control device 2 of the mobile body 1 relating to the third aspect, the estimation unit 205 estimates future load torque and electric torque for a predetermined time ahead based on the state variables, and the automatic setting unit 204 sets a torque limit value based on the estimated future load torque and electric torque.

[0178] In this way, the control device 2 can limit the electric torque in advance when a loss of synchronism is predicted in the future, thereby more reliably suppressing loss of synchronism of the magnetic geared motor 42.

[0179] (6) According to the sixth aspect, in the control device 2 of the mobile body 1 relating to the fourth aspect, the estimation unit 205 estimates future load torque and electric torque for a predetermined time ahead based on the state variables, and the automatic setting unit 204 sets a torque limit value based on the estimated future load torque and electric torque.

[0180] In this way, the control device 2 can limit the electric torque in advance when a loss of synchronism is predicted in the future, thereby more reliably suppressing loss of synchronism of the magnetic geared motor 42.

[0181] (7) According to a seventh aspect, the control device 2 of the moving body 1 is a control device 2 of the moving body 1 having a propeller 44 that is rotationally driven by a magnetic geared motor 42, and includes: a switching unit 202 that switches between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor 42, and an auto mode in which the torque limit value is automatically set; a manual setting unit 203 that sets the torque limit value to a value specified by the operator when switched to the manual mode; an automatic setting unit 204 that sets the torque limit value based on at least one of the load torque transmitted from the propeller 44 to the magnetic geared motor 42 and measurement data representing the state of the moving body 1 when switched to the auto mode; a limit value calculation unit 207 that calculates a limit value that limits at least one of a rotation speed command that specifies the rotation speed of the propeller 44 and a steering angle command that specifies the steering angle of the moving body 1 based on the torque limit value; and a limiter 206 that limits at least one of the rotation speed command and the steering angle command by a limit value.

[0182] In this way, the control device 2 can limit the load torque by limiting the rotation speed of the propeller 44. As a result, step-out can be more reliably avoided.

[0183] (8) According to the eighth aspect, the moving body 1 comprises a magnetic geared motor 42 having a low-speed rotor PPR and a high-speed rotor HSR, a propeller 44 rotationally driven by the magnetic geared motor 42, a steering gear 51 that changes the direction of travel, and a control device 2 relating to any one of the first to seventh aspects.

[0184] (9) According to the ninth aspect, the moving body 1 according to the eighth aspect further includes a torque limiting mechanism 42B provided between the low-speed rotor PPR and the propeller 44, which limits the torque transmitted between the propeller 44 and the low-speed rotor so that the torque does not exceed the maximum transmission torque of the high-speed rotor HSR and the low-speed rotor PPR.

[0185] By doing so, the moving body 1 can more reliably prevent the magnetic geared motor 42 from losing synchronization.

[0186] (10) According to a tenth aspect, the moving body 1 according to the eighth or ninth aspect further includes a flywheel 42C provided between the low-speed rotor PPR and the propeller 44, which damps the torsion angle fluctuations of the high-speed rotor HSR and the low-speed rotor PPR.

[0187] By doing so, the movable body 1 can provide appropriate damping to the torsion angle fluctuations of the low-speed rotor PPR and the high-speed rotor HSR, thereby more reliably suppressing loss of synchronization.

[0188] (11) According to a first aspect, a control method for a moving body (1) is a control method for a moving body (1) having a propeller (44) rotationally driven by a magnetic geared motor (42), and includes the steps of switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor (42) and an auto mode in which the torque limit value is automatically set; a step of setting the torque limit value to a value specified by the operator when switched to the manual mode; a step of setting the torque limit value based on at least one of the load torque transmitted from the propeller (33) to the magnetic geared motor (42) and measurement data representing the state of the moving body (1) when switched to the auto mode; and a step of limiting, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor (42) based on the difference between a rotation speed command that specifies the rotation speed of the propeller (44) and the measurement data for the rotation speed of the propeller (44).

[0189] (12) According to the twelfth aspect, the program causes the control device 2 of the moving body 1 having a propeller 44 rotationally driven by the magnetic geared motor 42 to execute the following steps: switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor 42, and an auto mode in which the torque limit value is automatically set; when switched to the manual mode, setting the torque limit value to a value specified by the operator; when switched to the auto mode, setting the torque limit value based on at least one of the load torque transmitted from the propeller 33 to the magnetic geared motor 42 and measurement data representing the state of the moving body 1; and limiting, with the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor 42 based on the difference between a rotation speed command that specifies the rotation speed of the propeller 44 and the measurement data for the rotation speed of the propeller 44.

[0190] According to the above aspect, it is possible to prevent the magnetic geared motor mounted on the moving body from losing synchronization.

[0191] REFERENCE SIGNS LIST 1 Mobile body 2 Control device 20 Processor 201 Control unit 202 Switching unit 203 Manual setting unit 204 Automatic setting unit 204A Selector 204B Rate limiting unit 205 Estimation unit 206 Limiter 206A First limiter 206B Second limiter 207 Limit value calculation unit 21 Memory 22 Storage 23 Communication interface 3 Main body unit 31 Sensor 33 Propulsion unit 4 Propulsion system 40 Inverter control device 41 Inverter 42 Magnetic geared motor 42A Magnetic gear unit 42B Torque limiting mechanism 42C Flywheel HSR High speed rotor PPR Low speed rotor JT, JT1, JT2 Joint (elastic joint) 43 Rotating shaft 44 Propulsion unit 45 Current sensor 46 Rotation angle sensor 5 Steering system 51 Steering gear 10 Operation unit

Claims

1. A control device for a moving body having a propeller driven by a magnetic geared motor, comprising: a switching unit for switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; a manual setting unit for setting the torque limit value to a value specified by the operator when switched to the manual mode; an automatic setting unit for setting the torque limit value based on at least one of the load torque transmitted from the propeller to the magnetic geared motor and measurement data indicating the state of the moving body when switched to the auto mode; and a limiter for limiting, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor based on the difference between a rotation speed command that specifies the rotation speed of the propeller and measurement data for the rotation speed of the propeller.

2. A control device for a moving body as described in claim 1, wherein the automatic setting unit refers to first limit value information that predetermines the relationship between the state of the moving body and the torque limit value, and sets a first torque limit value corresponding to the state of the moving body as the torque limit value.

3. A control device for a moving body as described in claim 1, further comprising an estimation unit that estimates the load torque based on state variables including measurement data representing the state of the moving body, and the automatic setting unit sets a second torque limit value corresponding to the estimated load torque as the torque limit value by referring to second limit value information that predetermines the relationship between the load torque and the torque limit value.

4. A control device for a mobile body as described in claim 1, further comprising an estimation unit that estimates the load torque based on a state variable including measurement data representing the state of the mobile body, wherein the automatic setting unit: determines a first torque limit value corresponding to the state of the mobile body by referring to first limit value information that predetermines a relationship between the state of the mobile body and the torque limit value; determines a second torque limit value corresponding to the estimated load torque by referring to second limit value information that predetermines a relationship between the load torque and the torque limit value; and sets the smaller of the first torque limit value and the second torque limit value as the torque limit value.

5. A control device for a moving body as described in claim 3, wherein the estimation unit estimates the load torque and the electric torque at a predetermined time in the future based on the state variables, and the automatic setting unit sets the torque limit value based on the estimated future load torque and the electric torque.

6. A control device for a moving body as described in claim 4, wherein the estimation unit estimates the load torque and the electric torque at a predetermined time in the future based on the state variables, and the automatic setting unit sets the torque limit value based on the estimated future load torque and the electric torque.

7. A control device for a moving body having a propeller driven by a magnetic geared motor, comprising: a switching unit for switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; a manual setting unit for setting the torque limit value to a value specified by the operator when switched to the manual mode; an automatic setting unit for setting the torque limit value based on at least one of the load torque transmitted from the propeller to the magnetic geared motor and measurement data representing the state of the moving body when switched to the auto mode; a limit value calculation unit for calculating a limit value to limit at least one of a rotation speed command that specifies the rotation speed of the propeller and a steering angle command that specifies the steering angle of the moving body based on the torque limit value; and a limiter for limiting at least one of the rotation speed command and the steering angle command by the limit value.

8. A moving body comprising: a magnetic geared motor having a low-speed rotor and a high-speed rotor; a propeller driven and rotated by the magnetic geared motor; a steering gear for changing a direction of travel; and a control device according to any one of claims 1 to 7.

9. A moving body according to claim 8, further comprising a torque limiting mechanism provided between the low-speed rotor and the propeller, which limits the torque transmitted between the propeller and the low-speed rotor so as not to exceed a maximum transmission torque of the high-speed rotor and the low-speed rotor.

10. The moving body according to claim 8, further comprising a flywheel provided between the low-speed rotor and the propeller for damping fluctuations in the twist angle of the high-speed rotor and the low-speed rotor.

11. A method for controlling a moving body having a propeller driven by a magnetic geared motor, comprising the steps of: switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; when switched to the manual mode, setting the torque limit value to a value specified by the operator; when switched to the auto mode, setting the torque limit value based on at least one of the load torque transmitted from the propeller to the magnetic geared motor and measurement data representing the state of the moving body; and limiting, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor based on the difference between a rotation speed command that specifies the rotation speed of the propeller and the measurement data for the rotation speed of the propeller.

12. A program for causing a control device for a moving body having a propeller driven by a magnetic geared motor to execute the following steps: switching between a manual mode in which an operator manually sets a torque limit value that limits the electric torque of the magnetic geared motor, and an auto mode in which the torque limit value is automatically set; when switched to the manual mode, setting the torque limit value to a value specified by the operator; when switched to the auto mode, setting the torque limit value based on at least one of the load torque transmitted from the propeller to the magnetic geared motor and measurement data representing the state of the moving body; and limiting, by the torque limit value, a torque command that adjusts the electric torque of the magnetic geared motor based on the difference between a rotation speed command that specifies the rotation speed of the propeller and the measurement data for the rotation speed of the propeller.

Images