WO2024133509A1

WO2024133509A1 - A powered watercraft and a method of implementing a dead man's switch on a powered watercraft

Info

Publication number: WO2024133509A1
Application number: PCT/EP2023/087033
Authority: WO
Inventors: Martin PRÅME MALMQVIST; Philip SVENINGSSON; Dimitrios Triantafillidis; Aleksandar RODZEVSKI; Daniel NORDAHL
Original assignee: Radinn Ab
Priority date: 2022-12-21
Filing date: 2023-12-20
Publication date: 2024-06-27
Also published as: SE2251527A1

Abstract

Disclosed is a powered watercraft (100) comprising a host device (102), and a driveline (106) configured to be received in the host device (102) The powered watercraft (100) further comprises a battery module (110), a propulsion module (108) configured to receive power delivered from the battery module (110), and a control unit (104) configured to control the power delivered from the battery module (110) to the propulsion module (108), at least one monitoring sensor (112, 114, 116). The at least one monitoring sensor (112, 114, 116) is configured to detect an electric load change of the battery module (110). The at least one monitoring sensor (112, 114, 116) is configured to provide one or more monitoring sensor signals to the control unit (104). The control unit (104) is configured to determine a user presence based on the one or more monitoring sensor signals, and in accordance with a determination that no user is present on the powered watercraft (100), the control unit (104) is configured to terminate the power delivered from the battery module (110) to the propulsion module (108).

Description

A POWERED WATERCRAFT AND A METHOD OF IMPLEMENTING A DEAD MAN’S SWITCH ON A POWERED WATERCRAFT

FIELD

The present invention relates to a powered watercraft. More specifically, the disclosure relates to a powered watercraft comprising a host device and a driveline configured to be received in the host device. Additionally, the present disclosure relates to a method for implementing a dead man’s switch on a powered watercraft.

BACKGROUND

Watercrafts, such as electrically powered watercrafts or personal watercrafts, may be quite powerful and fast, and thus, it is necessary to ensure that such watercrafts are do not continue to run if a user is no longer present. Typically, this is done by having a leash attached to a user and releasably attached to the watercraft. The leash may for example include a magnet, and only when this magnet is positioned on a corresponding magnet on the watercraft, the watercraft may run. If the user falls off, the magnet may be detached from the corresponding magnet on the watercraft and hence the watercraft may not run.

However, such a leash is not always desirable when riding a watercraft, and additionally, the time it takes between the user falling off and the watercraft stopping may be too long, as the leash needs to have a certain length so as not to impede the user’ s motion on the watercraft.

SUMMARY

It is an object of the present invention to mitigate, alleviate or eliminate one or more of the aboveidentified deficiencies and disadvantages in the prior art and solve at least the above mentioned problem.

According to a first aspect there is provided a powered watercraft comprising a host device, and a driveline configured to be received in the host device. The powered watercraft further comprises a battery module, a propulsion module configured to receive power delivered from the battery module, and a control unit configured to control the power delivered from the battery module to the propulsion module. The powered watercraft further comprises at least one monitoring sensor. The at least one monitoring sensor is configured to detect an electric load change of the battery module. The at least one monitoring sensor is configured to provide one or more monitoring sensor signals to the control unit. The control unit is configured to determine a user presence based on the one or more monitoring sensor signals. The control unit is further configured to, in accordance with a determination that no user is present on the powered watercraft, terminate the power delivered from the battery module to the propulsion module.

By the term terminate the power is hereby meant gradual termination of the power, delivered from the battery module to the propulsion module, to zero over a period of time or instant termination of the power delivered from the battery module to the propulsion module. The control unit, in accordance with a determination that no user is present on the powered watercraft, is configured to instantly terminate i.e. switch off the power delivered from the battery module to the propulsion module. The control unit may for example be configured to instantly terminate the power delivered from the battery module to the propulsion module by a hardware switch or a software switch. An example of a hardware switch, is a conventionally and commercially available switch. An example of a software switch is signal provided by the control unit to terminate the power delivered from the battery module to the propulsion module.

The control unit, in accordance with a determination that no user is present on the powered watercraft, is configured to gradually terminate the power delivered from the battery module to the propulsion module to zero. The control unit may be configured to gradually terminate the power, delivered from the battery module to the propulsion module over a period of time. The period of time may be in the order of seconds such as 1 second, 2 seconds, or 5 seconds. The period of time may be in the order of milliseconds such as 10 milliseconds, 50 milliseconds, or 100 milliseconds. The powered watercraft may comprise an electronic speed controller. The control unit may be configured to reduce the power delivered from the battery module to the propulsion module by means of the electronic speed controller. In other words, the control unit may be configured to reduce the speed of the powered watercraft by means of the electronic speed controller and hence reduce the power delivered from the battery module to the propulsion module.

The powered watercraft may be a battery powered watercraft such as an electrically-powered, waterjet-propelled surfboard, i.e. a jetboard, comprising a host device and a driveline.

The host device may be a flotation device configured to receive the driveline. The host device may be hull or a main body, such as a substantially rigid main body, for a powered watercraft, such as an electrical water-jet propelled surfboard. The driveline may be a removable driveline such that the removable driveline is configured to be received in the host device. Preferably, the driveline comprises the battery module, the propulsion module, the control unit and the at least one monitoring sensor.

The battery module is configured to deliver power to the propulsion module. The battery module may comprise a battery management system (BMS) configured to provide power conversion and a battery cell conditioning to rechargeable battery cells in the battery module. By the electric load change of the battery module is hereby meant how an electric load of the battery module changes over time. As the electric load of the battery module is dependent on the physical load of the powered watercraft, the electric load change of the battery module determines that no user is present on the powered watercraft.

The propulsion module may comprise an electrically-driven waterjet configured to propel the powered watercraft. The propulsion module may be provided with electrical power delivered from the battery module, e.g. by the propulsion module having a contacting portion with a plurality of electrical contacts configured to be electrically connected to a plurality of electrical contacts provided at a compatible contacting portion of the battery module. In this way, a direct current (DC) electrical output from the battery module may be provided to the electrical motor of the propulsion module, which may for example be a brushless DC motor or an induction motor powered by alternating current (AC) via a DC-to-AC converter.

An advantage of using the one or more monitoring sensor signals for determining that a user has fallen off a powered watercraft is that the use of a physical leash between the user and the watercraft is eliminated. Further, the powered watercraft may respond more quickly to the user absence, e.g. by turning off the power to the powered watercraft more quickly. It is an additional advantage that the control unit, using the monitoring sensor signals, is configured to terminate the power delivered from the battery module to the propulsion module as soon as it is established that the user has fallen off, without the user getting further away from the powered watercraft. It should be noted that in the conventional approach i.e. the physical leash, the termination of the power relies on a disconnection of the physical leash from the powered watercraft which may take a while and the user may hence need to swim a distance to reach the powered watercraft. Thereby, the first aspect of the present invention allows for turning off the power to the powered watercraft more quickly and hence the user may not need to swim a long distance to reach the powered watercraft.

In some embodiments, the one or more monitoring sensor signals comprises a battery current derived from the battery module to identify the electric load change of the battery module. The battery current derived from the battery module may also be referred to as the battery module current. The battery current may increase as the physical load, e.g. weight, on the powered watercraft increases. The battery current may decrease as the physical load on the powered watercraft decreases. If a user falls off the powered watercraft, the battery current derived from the battery module may decrease rapidly. Thereby, one or more monitoring sensor signals may decrease accordingly. Thereby, a sudden decrease in the battery module current may determine that no user is present on the powered watercraft. An advantage of the one or more monitoring sensor signals comprising a battery current may be that a powered watercraft may already have monitoring sensors to monitor the battery current. Thereby, no additional equipment may be needed.

In some embodiments, the one or more monitoring sensor signals comprises a propulsion module current derived from the propulsion module to identify the electric load change of the battery module. The propulsion module current may increase as the load, such as the physical load, on the powered watercraft increases. The propulsion module current may decrease as the load, such as the physical load, on the powered watercraft decreases. The propulsion module current may be a current measured at the propulsion module. The propulsion module current may be a current measured directly from the propulsion module. If a user is falls off the powered watercraft, the propulsion module current may decrease rapidly. Thereby, one or more monitoring sensor signals may decrease accordingly. Thereby, a sudden decrease in the propulsion module current may determine that no user is present on the powered watercraft. The propulsion module current may be a current measured at the electrically-driven waterjet which is configured to propel the powered watercraft. An advantage of the one or more monitoring sensor signals comprising a propulsion module current may be that a powered watercraft may already have monitoring sensors to monitor the propulsion module current. Thereby, no additional equipment may be needed.

In some embodiments, the one or more monitoring sensor signals comprises at least one propulsion module phase current derived from the propulsion module to identify the electric load change of the battery module. The propulsion module may comprise a system using phase power, e.g. single-phase power, three-phase power. In such cases, the one or more monitoring sensor signals may comprise at least one phase current from the propulsion module. Phase currents as monitoring signals may provide more detailed information about motor performance and its relationship to user presence. The propulsion module phase current may indicate the load change, such as a physical load change, on the powered watercraft. If a user is falls off the powered watercraft, the propulsion module phase current may change rapidly. Thereby, one or more monitoring sensor signals may change accordingly. Thereby, a sudden change in the propulsion module phase current may determine that no user is present on the powered watercraft. An advantage of the one or more monitoring sensor signals comprising a propulsion module phase current may be that a powered watercraft may already have monitoring sensors to monitor the propulsion module phase current. Thereby, no additional equipment may be needed.

In some embodiments, the at least one monitoring sensor comprises at least one shunt resistor configured to measure a current. The current may be the battery current derived from the battery module. Alternatively or in addition, the current may be the propulsion module current derived from the propulsion module. Alternatively or in addition, the current may be the propulsion module phase current derived from the propulsion module. Thereby, the current such as the battery current, the propulsion current and/or the propulsion module phase current may be measured to determine that no user is present on the powered watercraft. For example, the battery module and/or the propulsion module may comprise one or more shunt resistors. If the propulsion module comprises a motor, one or more shunt resistors may measure current to an electronic speed controller corresponding to the motor. If the battery module comprises a battery pack, one or more shunt resistors may measure current of the battery pack. One or more shunt resistors may measure phase current in a propulsion module. It is an advantage that shunt resistors may already be present in the powered watercraft for other purposes. Thereby, no additional equipment may be needed.

In some embodiments, the propulsion module comprises a motor. The at least one propulsion module phase current may be derived from the motor. The at least one monitoring sensor may comprise a sensor configured to detect a rotational speed of the motor based on the at least one propulsion module phase current derived from the motor. The rotational speed of the motor may correspond to an electric load of the motor, which in turn may correspond to the load of the powered watercraft i.e. presence of the user. For example, when the user is no longer present, less work may be required to run the motor, leading to a change in motor load, and the rotational speed of the motor may subsequently decrease. As a rapid decrease in the rotational speed of the motor may correspond to decreased phase current in the system powering the motor, such a system may be used to detect or augment detection of when a user falls off the powered watercraft The rotational speed of the motor may be measured in revolutions per minute (rpm).

In some embodiments, the at least one monitoring sensor comprises a phase current sensor and/or a DC link sensor. The propulsion module may comprise a sensorless motor. The sensorless motor may require a separate sensor to detect the monitoring sensor signals. The sensorless motor may be a conventionally and commercially available motor. The sensorless motor may be a brushless direct current (BLDC) motor.

In some embodiments, a voltage of the battery module and/or a voltage of the propulsion module is at most 400 V. In some embodiments, the battery module current, the propulsion module current, and/or the at least one propulsion module phase current is at most 600 A. Thereby, different ranges of current and/or voltage may be delivered to the battery module and/or to the propulsion module.

The voltage of the battery module may be in the range of 0 to 400 V. The voltage of the battery module may be in the range of 1 to 399 V. The voltage of the battery module may be in the range of 0 to 250 V. The voltage of the battery module may be in the range of 1 to 249 V. The voltage of the battery module may be in the range of 0 to 75 V. The voltage of the battery module may be in the range of 1 to 74 V. The voltage of the battery module may be in the range of 0 to 60 V. The voltage of the battery module may be in the range of 1 to 59 V.

The voltage of the propulsion module may be in the range of 0 to 400 V. The voltage of the propulsion module may be in the range of 1 to 400 V. The voltage of the propulsion module may be in the range of 0 to 250 V. The voltage of the propulsion module may be in the range of 1 to 250 V. The voltage of the propulsion module may be in the range of 0 to 75 V. The voltage of the propulsion module may be in the range of 1 to 74 V. The voltage of the propulsion module may be in the range of 0 to 60 V. The voltage of the propulsion module may be in the range of 1 to 60 V.

The battery module current may be in the range of 0 to 600 A. The battery module current may be in the range of 1 to 600 A. The battery module current may be in the range of 0 to 250 A. The battery module current may be in the range of 1 to 250 A. The battery module current may be in the range of 0 to 75 A. The battery module current may be in the range of 1 to 75 A. The battery module current may be in the range of 0 to 60 A. The battery module current may be in the range of 1 to 60 A. The propulsion module current may be in the range of 0 to 600 A. The propulsion module current may be in the range of 1 to 600 A. The propulsion module current may be in the range of 0 to 250 A. The propulsion module current may be in the range of 1 to 250 A. The propulsion module current may be in the range of 0 to 75 A. The propulsion module current may be in the range of 1 to 75 A. The propulsion module current may be in the range of 0 to 60 A. The propulsion module current may be in the range of 1 to 60 A.

The at least one propulsion module phase current may be in the range of 0 to 600 A. The at least one propulsion module phase current may be in the range of 1 to 600 A. The at least one propulsion module phase current may be in the range of 0 to 250 A. The at least one propulsion module phase current may be in the range of 1 to 250 A. The at least one propulsion module phase current may be in the range of 0 to 75 A. The at least one propulsion module phase current may be in the range of 1 to 75 A. The at least one propulsion module phase current may be in the range of 0 to 60 A. The at least one propulsion module phase current may be in the range of 1 to 60 A.

In some embodiment, the driveline further comprises an accelerometer. The accelerometer may be configured to provide accelerometer data to the control unit. The control unit may further be configured to determine the user presence based on the accelerometer data. The accelerometer data may comprise e.g. acceleration. The accelerometer data may change in response e.g. to a sudden absence of the user. For example, when the user falls off the powered watercraft but the propulsion module continues, the acceleration may increase since the propulsion module is producing a similar amount of power but the mass associated with the powered watercraft has decreased. Thereby, it is an advantage that the control unit may further be configured to determine the user presence based on the accelerometer data since the use of the accelerometer data may increase the accuracy of determining the user’s presence.

In some embodiments, the driveline further comprises a gyroscope. The gyroscope may be configured to provide gyroscopic data to the control unit. The control unit may further be configured to determine the user presence based on the gyroscopic data. The gyroscopic data may comprise e.g. angular velocity and/or orientation. The gyroscopic data may change in response to a sudden absence of the user. For example, when the user falls off the powered watercraft but the propulsion module continues, the orientation of the powered watercraft may change since there is no longer a user controlling it. Thereby, it is an advantage that the control unit may further be configured to determine the user presence based on the gyroscopic data since the use of the gyroscopic data may increase the accuracy of determining the user’s presence, particularly in combination with the accelerometer data.

In some embodiments, the driveline further comprises a throttle. The throttle may be configured to provide throttle data to the control unit. The control unit may further be configured to determine the user presence based on the throttle data. The throttle may affect the thrust of the jet. The throttle data may be, e.g. a throttle value, a throttle curve, and/or a throttle curve parameter. A throttle value may determine how the throttle behaves. In some embodiments, a throttle value may comprise the degree of activation of a handle. In some embodiments, a throttle curve may set the relationship between degree of activation of a handle, such as a remote handle, and the actual throttle command delivered to the propulsion module. In some embodiments, the curve may be linear, so that, 0% activation of the handle may correspond to a 0% throttle command, 50% activation of the handle may correspond to 50% throttle, 100% activation of the handle (complete de-press) may correspond to 100% throttle, and so on. In some embodiments, throttle curve parameters may be adjusted to adjust this characteristic.

It is an advantage that the use of data from the throttle may increase the accuracy of detecting user presence, particularly in combination with the accelerometer data. For example, where the battery module current decreases but the actual throttle command delivered to the propulsion module remains the same, it may indicate that no user is present on the powered watercraft. On the other hand, where the battery module current decreases and the actual throttle command is reduced, it may indicate that the user is still present on the powered watercraft and that the user has simply lowered the throttle.

In some embodiments, the user presence is determined based on the accelerometer data, the gyroscopic data, and/or the throttle data derived from previous rides. The accelerometer data, the gyroscopic data, and/or the throttle data derived from the previous rides may further be used to determine the user presence in an existing ride. For example, the accelerometer data, the gyroscopic data, and/or the throttle value from previous rides could be compared to corresponding data from an existing ride to determine the user presence. The accelerometer data, the gyroscopic data, and/or the throttle data derived from the previous rides may be used in a similar manner as the one or more monitoring sensor signals derived from the previous rides defined above. For instance, such data from the previous rides may be used to ascertain that no user is present on the powered watercraft. It is an advantage that the accelerometer data, the gyroscopic data, and/or the throttle data derived from the previous rides may e.g. be used as supplements to the one or more monitoring sensor signals derived from the previous rides i.e. dead man’s switch from previous rides to determine the user presence in an existing ride. Thereby, this in turn may determine the user presence in a more accurate manner.

For example, dead man’s switch data from a manual dead man’s switch may act as a useful final determination in whether or not a user is present. In using the data from previous rides, activation of a manual dead man’s switch, e.g. a magnetic tag attached to the user that is removed when the user is a certain distance from the powered watercraft, may be used as a reliable determination of whether the user is present or not.

In some embodiments, the user presence is determined based on one or more monitoring sensor signals derived from previous rides. The one or more monitoring sensor signals derived from the previous rides i.e. dead man’s switch from previous rides may determine the user presence in an existing ride. One or more monitoring sensor signals derived from the previous rides i.e. data from previous rides may be used to determine if no user in present on the powered watercraft in an existing ride. For example, as defined above, a sudden decrease in the battery module current may indicate that no user is present on the powered watercraft. The degree of suddenness and decrease of the battery module current, measured on the previous rides, when it was determined that no user was present on the powered watercraft may be used to determine that no user in present on the powered watercraft in an existing ride. Another example, the propulsion module current and/or the propulsion module phase current, measured on the previous rides, may be used to determine if no user in present on the powered watercraft in an existing ride. It is an advantage since the one or more monitoring sensor signals from the previous rids are derived from empirical measurements of performance rather than speculation: Thereby, they may increase the accuracy of the prediction of user presence.

In some embodiments, the control unit is configured to determine the user presence based on the accelerometer data, the gyroscopic data, and/or the throttle data reaching a first threshold value. The control unit may be configured to determine the user presence based on the accelerometer data, the gyroscopic data, and/or the throttle data deviating from the first threshold value. Thereby, in accordance with a determination that the value of the accelerometer data, the gyroscopic data, and/or the throttle data reaches or passes the first threshold value, the control unit may terminate the power delivered from the battery module to the propulsion module.

For example, a throttle value may be used to estimate an intended current, upon which a first threshold for a monitoring signal sensor can be based. Where the throttle value is higher, the intended current may also be higher, and where the throttle value it lower, the intended current may also be lower. The intended current may then be compared to a measurement of a battery module current and/or a propulsion module current, with the threshold based on both values. It is an advantage that the determination of the user presence based on the first threshold value may be implemented in the control unit in a simple manner.

In some embodiments, the control unit is configured to determine the user presence based on the one or more monitoring sensor signals reaching a second threshold value. The control unit may be configured to determine the user presence based on the one or more monitoring sensor signals reaching a second threshold value. Thereby, in accordance with a determination that the value of the one or more monitoring sensor signals reaches or passes the second threshold value, the control unit may terminate the power delivered from the battery module to the propulsion module. For example, the battery module current may rise from a lower value to a higher value within a period of time, indicating that a rider has fallen off, as described above. The higher value of the battery module current may e.g. be used as the second threshold value. It is an advantage that the determination of the user presence based on the second threshold value may be implemented in the control unit in a simple manner.

The control unit may be configured to determine the user presence based on the one or more monitoring sensor signals reaching a second threshold value as supplement to determining the user presence based on the accelerometer data, the gyroscopic data, and/or the throttle data reaching the first threshold value. Thereby, this in turn may determine the user presence in a more accurate manner.

In some embodiments, the control unit is further configured to control driveline performance based on the one or more monitoring sensor signals, the driveline performance comprising an increase of speed and/or a decrease of speed of the powered watercraft.

The control unit may determine that the user is present on the powered watercraft. In accordance with the determination that the user is present on the powered watercraft, the control unit may be configured to control the driveline performance base on the one or more monitoring sensor signals such as increasing the rotational speed or decreasing the rotational speed of the powered watercraft.

In some embodiments, the control unit is further configured to control driveline parameters based on the one or more monitoring sensor signals, the driveline parameters comprising battery capacity, amount of power provided to the propulsion module, motor current, maximum motor current, motor rpm, maximum motor rpm, throttle value, throttle curve, and/or throttle curve parameters. Thereby, the control unit may control the driveline parameters based on the one or more monitoring sensor signals to assist the user in regaining control of the powered watercraft.

According to a second aspect, there is provided a method for implementing a dead man’s switch on a powered watercraft. The powered watercraft comprises a host device, and a driveline configured to be received in the host device. The powered watercraft further comprises a battery module, a propulsion module configured to receive power delivered from the battery module, a control unit configured to control the power delivered from the battery module to the propulsion module, at least one monitoring sensor. The at least one monitoring sensor is configured to detect an electric load change of the battery module. The at least one monitoring sensor is configured to provide one or more monitoring sensor signals to the control unit. The method comprises receiving monitoring sensor signals in the control unit. The method further comprises determining a user presence based on the received monitoring sensor signals. The method further comprises terminating the power delivered from the battery module to the propulsion module in accordance with a determination that no user is present on the powered watercraft. The powered watercraft of the second aspect corresponds to the powered watercraft of the first aspect. This aspect may generally present the same or similar advantages as the first aspect.

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure.

Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which:

Figs. 1a-g schematically illustrate exemplary powered watercrafts.

Fig. 2 illustrates an example of a monitoring sensor signal over time.

Figs. 3a-b show examples of throttle curves.

Fig. 4 shows a method of implementing a dead man’s switch based on the monitoring sensor signals.

DETAILED DESCRIPTION

The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

Figs. 1a-1c show a powered watercraft 100 comprising a host device 102, and a driveline 106 configured to be received in the host device 102, wherein the driveline 106 comprises: a battery module 110, a propulsion module 108 configured to be powered by the battery module 110, a control unit 104 configured to control battery power delivered to the propulsion module 108. The powered watercraft 100 further comprising at least one monitoring sensor 112, monitoring sensor 112 providing monitoring sensor signals to the control unit 104, wherein the control unit 104 is configured to determine a user presence based on the radar sensor signals from the at least one monitoring sensor 112 and in accordance with a determination that no user is present on the powered watercraft, the control unit is configured to terminate power transfer from the battery module 110 to the propulsion module 108.

As is seen in Fig. 1a, the at least one monitoring sensor 112 may be in the battery module 110.

As is seen in Fig. 1b, the at least one monitoring sensor 112 may be in the propulsion module 108.

As is seen in Fig. 1c, the monitoring sensors 112, 114, and 116 may be in the propulsion module

108.

As is seen in Fig. 1 d, the at least one monitoring sensor 112 may be provided at or in the driveline 106.

As is seen in Fig. 1e, the at least one monitoring sensor 112 may be in the battery module 110 and the control unit 104 may also be in the battery module 110, e.g. where the control unit is a battery management system.

As is seen in Fig. 1 f, the at least one monitoring sensor 112 may be provided at or in the driveline 106.

As is seen in Fig. 1g, the monitoring sensors 112, 114, and 116 and motor 118 may be in the propulsion module 108. This may be the case e.g., where the motor 118 is a three phase motor in the propulsion module and the monitoring sensors 112, 114, and 116 detect propulsion module phase currents of the three phase motor. The monitoring sensors 112, 114, and 116 may be, for example, shunt resistors.

As is seen in Fig. 1 h, the powered watercraft may further comprise accelerometer 120, gyroscope 122, and throttle 124. These may provide an additional source of data for implementing a dead man’s switch.

As power to the propulsion module is terminated by the control unit, when it is determined that there is no user at the powered watercraft, the at least one monitoring sensor 112 and the control unit 104 implements a dead man’s switch for the powered watercraft 100.

Fig. 2 shows an example of a monitoring sensor signal over time. In this example, the monitoring sensor signal may be a current. In chart 200, the y-axis 202 shows the current, and the x-axis 204 shows time. Curve 206 shows the current over time, where the current initially rises, e.g. to start a motor, then plateaus, then suddenly decreases. The sudden decrease may be in response to a sudden load change, e.g. when a user falls off, which may decrease the current, as described above.

Figures 3a-b show different examples of curves 300, 320. The curves 300, 320 correspond to throttle curves which may be adjusted in response to a change in user presence. The propulsion module may comprise a throttle, where the throttle affects the thrust of the jet. The throttle curve may adjust an attribute such as the motor rotational speed in response to a change in the user presence, which may be determined by the control unit based on the monitoring sensor signals.

The throttle value may be changed from a first value to a second value and/or from a second value to a first value. The motor rotational speed may be adjusted in different ways in response to the change in throttle value, for example, to change in a linear, stepwise, or exponential manner. The throttle may be returned to a different value, allowing variations between time and values. Further, the throttle curve may be combined with other driveline parameters such a maximum rotational speed. The adjustments to the throttle curve may result in the powered watercraft increasing or decreasing rotational speed in different ways.

In the examples of throttle curves shown, throttle value over time 306 shows the throttle value over time, throttle curve 308 shows the amount of throttle over time, and current over time 310 shows the current over time. X-axis 304 shows the time and y-axis 302 shows the relative increases and decreases of throttle value over time 306, throttle curve 308, and current over time 310.

Figure 3a shows an example where a throttle curve responds to determination that a user is not present. When the throttle over time 306 changes from a first value to a second value, where the second value is higher than the first, the throttle curve 308 increases gradually until the throttle curve is at a plateau. The current 310 also initially also increases as the throttle value increases, until it reaches a peak where the throttle is performing at constant throttle and the current plateaus. However, when current 310 suddenly drops with no change in throttle value 306, it may be determined that the user has fallen off, and the throttle curve 308 has an immediate stop response, immediately cutting off the throttle to slow the powered watercraft.

Figure 3b shows an example where the throttle curve responds to a lowered throttle value. When the throttle over time 306 changes from a first value to a second value, as above, the throttle curve 308 increases gradually until the throttle curve is at a plateau. The current 310 also initially also increases as the throttle value increases, until it reaches a peak where the throttle is performing at constant throttle and the current plateaus. When the throttle over time 306 changes from the second value to the first, the motor rotational speed over time 308 decreases steadily but gradually, in a slow linear stop response, resulting in a gradual stop to the powered watercraft. Here, a sudden stop may not be necessary because the decrease in current 310 is in response to a change in throttle value 306 and may be a response to a user action rather than an indication that the user has fallen off.

Fig. 4 shows a method 400 of implementing a dead man’s switch based on the monitoring sensor signals. The method may be implemented, for example, in a powered watercraft comprising a host device and a driveline, where the driveline comprises a battery module and a propulsion module. The propulsion module may further comprise a motor. Other examples of a powered watercraft may be seen in e.g. Fig. 1a-h.

Step 402 shows receiving monitoring sensor signals in the control unit. As discussed above, such a monitoring sensor signal may be, e.g., a battery module current, a propulsion module current, and/or a propulsion module phase current. The monitoring sensor signal may occur in several ranges, e.g., up to 250 A or 400 A. The voltage of the propulsion module and/or battery module may also occur in several ranges, e.g. up 60 V, 75 V, or 400V. The monitoring sensor signal may be detected by a monitoring sensor, which may be e.g. a shunt resistor, phase current resistor, and/or DC link sensor.

Step 404 shows determining a user presence based on the monitoring sensor signals from the at least one monitoring sensor. Once the monitoring sensor signal is obtained, it may be used to make a determination of whether a user is present. For example, as discussed above, a decrease in current may indicate that a user has fallen off the powered watercraft.

Step 406 shows terminating power transfer from the battery module to the propulsion module in accordance with a determination that no user is present on the powered watercraft. Upon detection that a user is no longer present, e.g. the user has fallen off. This may be done, for example, through the control unit.

Although particular features have been shown and described, it will be understood that they are not intended to limit the claimed invention, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed invention. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed invention is intended to cover all alternatives, modifications and equivalents.

ITEMS:

1. A powered watercraft comprising a host device, and a driveline configured to be received in the host device, wherein the powered watercraft further comprises: a battery module, a propulsion module configured to receive power delivered from the battery module, and a control unit configured to control the power delivered from the battery module to the propulsion module, at least one monitoring sensor, wherein the at least one monitoring sensor is configured to detect an electric load change of the battery module, wherein the at least one monitoring sensor is configured to provide one or more monitoring sensor signals to the control unit, wherein the control unit is configured to determine a user presence based on the one or more monitoring sensor signals, and in accordance with a determination that no user is present on the powered watercraft, the control unit is configured to terminate the power delivered from the battery module to the propulsion module.

2. The powered watercraft according to any of the preceding items, wherein the one or more monitoring sensor signals comprises a battery current derived from the battery module to identify the electric load change of the battery module.

3. The powered watercraft according to any of the preceding items, wherein the one or more monitoring sensor signals comprises a propulsion module current derived from the propulsion module to identify the electric load change of the battery module.

4. The powered watercraft according to any of the preceding items, wherein the one or more monitoring sensor signals comprises at least one propulsion module phase current derived from the propulsion module to identify the electric load change of the battery module.

5. The powered watercraft according to any of the preceding items, wherein the at least one monitoring sensor comprises at least one shunt resistor configured to measure a current.

6. The powered watercraft according to item 4, wherein the propulsion module comprises a motor, wherein the at least one propulsion module phase current is derived from the motor, and wherein the at least one monitoring sensor comprises a sensor configured to detect a rotational speed of the motor based on the at least one propulsion module phase current derived from the motor. The powered watercraft, according to item 6, wherein the at least one monitoring sensor comprises a phase current sensor and/or a DC link sensor. The powered watercraft according to any of the preceding items, wherein a voltage of the battery module and/or a voltage of the propulsion module is at most 400 V. The powered watercraft according to any of items 4-8, wherein the battery module current, the propulsion module current, and/or the at least one propulsion module phase current is at most 600 A. The powered watercraft according to any of the preceding items, wherein the driveline further comprises an accelerometer, the accelerometer is configured to provide accelerometer data to the control unit, and wherein the control unit is further configured to determine the user presence based on the accelerometer data. The powered watercraft according to any of the preceding items, wherein the driveline further comprises a gyroscope, the gyroscope being configured to provide gyroscopic data to the control unit, and wherein the control unit is further configured to determine the user presence based on the gyroscopic data. The powered watercraft according to any of the preceding items, wherein the driveline further comprises a throttle, the throttle being configured to provide throttle data to the control unit, and wherein the control unit is further configured to determine the user presence based on the throttle data. The powered watercraft according to any of the items 10, 11 or 12, wherein the user presence is determined based on the accelerometer data, the gyroscopic data, and/or the throttle data derived from previous rides. The powered watercraft according to any of the preceding items, wherein the user presence is determined based on one or more monitoring sensor signals derived from previous rides. The powered watercraft according to any of the items 10, 11 , 12, or 14 wherein the control unit is configured to determine the user presence based on the accelerometer data, the gyroscopic data, and/or the throttle data reaching a first threshold value. The powered watercraft according to any of the preceding items, wherein the control unit is configured to determine the user presence based on the one or more monitoring sensor signals reaching a second threshold value. The powered watercraft according to any of the preceding items, wherein the control unit is further configured to control driveline performance based on the one or more monitoring sensor signals, the driveline performance comprising an increase of speed and/or a decrease of speed of the powered watercraft. The powered watercraft according to any of the preceding items, wherein the control unit is further configured to control driveline parameters based on the one or more monitoring sensor signals, the driveline parameters comprising battery capacity, amount of power provided to the propulsion module, motor current, maximum motor current, motor rpm, maximum motor rpm, throttle value, throttle curve, and/or throttle curve parameters. A method for implementing a dead man’s switch on a powered watercraft, the powered watercraft comprising a host device, and a driveline configured to be received in the host device, wherein the powered watercraft further comprises: a battery module, a propulsion module configured to receive power delivered from the battery module, a control unit configured to control the power delivered from the battery module to the propulsion module, at least one monitoring sensor, wherein the at least one monitoring sensor is configured to detect an electric load change of the battery module, wherein the at least one monitoring sensor is configured to provide one or more monitoring sensor signals to the control unit, the method comprising: receiving monitoring sensor signals in the control unit; determining a user presence based on the received monitoring sensor signals; and terminating the power delivered from the battery module to the propulsion module in accordance with a determination that no user is present on the powered watercraft. LIST OF REFERENCES

100 Powered watercraft

102 Host device

106 Driveline

110 Battery module

104 Control unit

108 Propulsion module

112, 114, 116 Monitoring sensor

118 Motor

120 Accelerometer

122 Gyroscope

124 Throttle

200 Chart

202 Current

204 Time

206, 300, 320 Curve

306 Throttle value

308 Throttle curve

302 Relative increases and decreases

304 Time

306 Throttle value over time

308 Throttle curve over time

310 Throttle current over time

400 Method

402 Method receiving

404 Method determining

406 Method terminating

Claims

1. A powered watercraft (100) comprising a host device (102), and a driveline (106) configured to be received in the host device (102), wherein the powered watercraft (100) further comprises: a battery module (110), a propulsion module (108) configured to receive power delivered from the battery module (110), and a control unit (104) configured to control the power delivered from the battery module (110) to the propulsion module (108), at least one monitoring sensor (112, 114, 116), wherein the at least one monitoring sensor (112, 114, 116) is configured to detect an electric load change of the battery module (110), wherein the at least one monitoring sensor (112, 114, 116) is configured to provide one or more monitoring sensor signals to the control unit (104), wherein the control unit (104) is configured to determine a user presence based on the one or more monitoring sensor signals, and in accordance with a determination that no user is present on the powered watercraft (100), the control unit (104) is configured to terminate the power delivered from the battery module (110) to the propulsion module (108).

2. The powered watercraft (100) according to claim 1, wherein the one or more monitoring sensor signals comprises a battery current (202) derived from the battery module (110) to identify the electric load change of the battery module (110).

3. The powered watercraft (100) according to any of the preceding claims, wherein the one or more monitoring sensor signals comprises a propulsion module current derived from the propulsion module (108) to identify the electric load change of the battery module (110).

4. The powered watercraft (100) according to any of the preceding claims, wherein the one or more monitoring sensor signals comprises at least one propulsion module phase current derived from the propulsion module (108) to identify the electric load change of the battery module (110).

5. The powered watercraft (100) according to any of the preceding claims, wherein the at least one monitoring sensor (112, 114, 116) comprises at least one shunt resistor configured to measure a current (202).

6. The powered watercraft (100) according to claim 4, wherein the propulsion module (108) comprises a motor (118), wherein the at least one propulsion module phase current is derived from the motor (118), and wherein the at least one monitoring sensor (112, 114, 116) comprises a sensor configured to detect a rotational speed of the motor (118) based on the at least one propulsion module phase current derived from the motor (118).

7. The powered watercraft (100), according to claim 6, wherein the at least one monitoring sensor (112, 114, 116) comprises a phase current sensor and/or a DC link sensor.

8. The powered watercraft (100) according to any of the preceding claims, wherein a voltage of the battery module (110) and/or a voltage of the propulsion module (108) is at most 400 V.

9. The powered watercraft (100) according to any of claims 4-8, wherein the battery module current, the propulsion module current, and/or the at least one propulsion module phase current is at most 600 A.

10. The powered watercraft (100) according to any of the preceding claims, wherein the driveline (106) further comprises an accelerometer (120), the accelerometer (120) is configured to provide accelerometer data to the control unit (104), and wherein the control unit (104) is further configured to determine the user presence based on the accelerometer data.

11. The powered watercraft (100) according to any of the preceding claims, wherein the driveline (106) further comprises a gyroscope (122), the gyroscope (122) being configured to provide gyroscopic data to the control unit (104), and wherein the control unit (104) is further configured to determine the user presence based on the gyroscopic data.

12. The powered watercraft (100) according to any of the preceding claims, wherein the driveline (106) further comprises a throttle (124), the throttle (124) being configured to provide throttle data to the control unit (104), and wherein the control unit (104) is further configured to determine the user presence based on the throttle data.

13. The powered watercraft (100) according to any of the claims 10, 11 or 12, wherein the user presence is determined based on the accelerometer data, the gyroscopic data, and/or the throttle data derived from previous rides.

14. The powered watercraft (100) according to any of the preceding claims, wherein the user presence is determined based on one or more monitoring sensor signals derived from previous rides.

15. The powered watercraft (100) according to any of the claims 10, 11 , 12, or 14 wherein the control unit (104) is configured to determine the user presence based on the accelerometer data, the gyroscopic data, and/or the throttle data reaching a first threshold value.

16. The powered watercraft (100) according to any of the preceding claims, wherein the control unit (104) is configured to determine the user presence based on the one or more monitoring sensor signals reaching a second threshold value.

17. The powered watercraft (100) according to any of the preceding claims, wherein the control unit (104) is further configured to control driveline performance based on the one or more monitoring sensor signals, the driveline performance comprising an increase of speed and/or a decrease of speed of the powered watercraft (100).

18. The powered watercraft (100) according to any of the preceding claims, wherein the control unit (104) is further configured to control driveline parameters based on the one or more monitoring sensor signals, the driveline parameters comprising battery capacity, amount of power provided to the propulsion module, motor current, maximum motor current, motor rpm, maximum motor rpm, throttle value, throttle curve (308), and/or throttle curve parameters.

19. A method (400) for implementing a dead man’s switch on a powered watercraft (100), the powered watercraft (100) comprising a host device (102), and a driveline (106) configured to be received in the host device (102), wherein the powered watercraft (100) further comprises: a battery module (110), a propulsion module (108) configured to receive power delivered from the battery module (110), a control unit (104) configured to control the power delivered from the battery module (110) to the propulsion module, at least one monitoring sensor (112, 114, 116), wherein the at least one monitoring sensor (112, 114, 116) is configured to detect an electric load change of the battery module (110), wherein the at least one monitoring sensor (112, 114, 116) is configured to provide one or more monitoring sensor (112, 114, 116) signals to the control unit (104), the method (400) comprising: receiving (402) monitoring sensor (112, 114, 116) signals in the control unit (104); determining (404) a user presence based on the received monitoring sensor (112, 114, 116) signals; and

- terminating (406) the power delivered from the battery module (110) to the propulsion module (108) in accordance with a determination that no user is present on the powered watercraft (100).