Technical field

The present disclosure 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, wherein the driveline comprises a battery module a propulsion module configured to be powered by the battery module and a control unit configured to control battery power delivered to the propulsion module. Additionally, the present disclosure relates to the implementation of a dead man's switch, to ensure safety when a person falls off a powered watercraft.

Background art

Powered watercrafts, such electrically powered watercrafts, such as what may be termed as personal watercrafts may be quite powerful watercrafts, and thus, it is necessary to ensure that such watercrafts are powered off when a user falls off such powered watercrafts.

Typically, this is done by having a leash 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 powered watercraft, will power be transferred from the battery to the water jet, so that the watercraft can be powered on. Likewise, if a user falls off, the connection between the two magnets will be disconnected, and power will be turned off. Hereby, it is ensured that when a user falls off, power to the jet motor will be terminated and the watercraft will come to a stand-still.

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

Summary

It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified 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, wherein the driveline comprises: a battery module, a propulsion module configured to be powered by the battery module, and a control unit configured to control battery power delivered to the propulsion module. The powered watercraft further comprises at least one radar sensor, wherein the at least one radar sensor has a field of view including at least a part of a user. The radar sensor provides radar sensor signals to the control unit, and the control unit is configured to determine a user presence based on the radar sensor signals from the at least one radar sensor. 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 to the propulsion module.

According to a second aspect, a method 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. The driveline comprises: a battery module, a propulsion module configured to be powered by the battery module, a control unit configured to control battery power delivered to the propulsion module, the powered watercraft further comprising at least one radar sensor, wherein the at least one radar sensor has a field of view including at least a part of a user, the method comprising: receiving radar sensor signals in the control unit, determining a user presence based on the radar sensor signals from the at least one radar sensor, and 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.

According to some embodiments, the at least one radar sensor and the control unit implement a dead man's switch for the powered watercraft. The power to the propulsion unit is terminated when a user is bodily removed from control of the watercraft.

It is an advantage of using a radar sensor for determining that a user has fallen off a powered watercraft, in that the use of a physical leash between the user and the watercraft is eliminated. It is an additional advantage that the control unit, using the radar sensor signals, can terminate power transfer from the battery module to the propulsion module as soon as it is established that the user has fallen off, without awaiting that the user get so far away from the watercraft that e.g. a leash is disconnected from the powered watercraft.

In some embodiments, the host device containing the battery module and the propulsion module has an active surface. The active surface may be configured to support a user during use of the powered watercraft. An active volume may be defined above the active surface, the active volume being configured to accommodate at least a part of a user during use. In some embodiments, the active volume is defined by the field of view of the at least one radar sensor. In some embodiments, the radar sensor is facing forward. In some embodiments, the radar sensor is facing backwards, In some embodiments, the radar sensor is facing upward. In some embodiments, more radar sensors have different field of views, and may be facing in different directions. In some embodiments, the at least one radar sensor is powered by the battery module. It is an advantage of powering the radar sensor by the battery module, as there is no need for any additional power supply. However, in some embodiments, it may be preferred to power the at least one radar sensor by a separate power supply. For example if the radar sensor is positioned at a position away from the battery module, a separate power supply may be advantageous.

According to some embodiments, the at least one radar sensor is provided in the battery module, such as integrated in a battery module surface, the battery module surface forming part of the active surface. For example, the at least one radar sensor may be arranged in a top surface of the battery module, the top surface of the battery module forming part of the active surface. Another example, the at least one radar sensor may be arranged on the top surface of the battery module, the top surface of the battery module forming part of the active surface. Hereby, the battery module and the at least one radar sensor may be manufactured as one unit. This will e.g. ensure that the battery module including the radar sensor can be provided as a waterproof battery module including the at least one radar sensor.

It is an advantage of using a radar sensor as no open or visible aperture needs to be provided, thereby ensuring that water tightness can be achieved. Additionally, no visible indication is needed.

According to some embodiments, the powered watercraft the powered watercraft comprises two or more radar sensors and thereby enable use of triangulation to determine user presence.

According to some embodiments, at least two radar sensors are provided. In some embodiments, the at least one radar sensor comprises two sensors. The two sensors may provide a field of view covering the watercraft including the at least part of a user. Two sensors may be arranged at different positions of the powered watercraft. The two sensors may have different fields of views i.e. no overlapping field of view. Alternatively, the two sensors may have an overlapping field of view. For example, the two sensors may be arranged at the host device. The two sensors may be arranged in/on a top surface of the host device. The two sensors may be arranged at opposite sides of the host device. For instance, the two sensors may be arranged at opposite sides of the top surface of the host device. Thereby, there may be a distance between the two sensors. The distance may correspond to a length of the host device, the distance may correspond to two thirds of the host device length, the distance may correspond to half the host device length, the distance may correspond to one third of the host device length. The two sensors may have different field of views. For examples, one of the two sensors may face backwards i.e. facing a rear side of the watercraft and the other one of the two sensors may face forwards i.e. facing a front side of the watercraft. Alternatively, the two sensors may have an overlapping field of view. The two sensors may be arranged at different positions at/in/on the host device. In some embodiments, the two sensors may be provided adjacent each other, such as adjacent each other in/on a middle part of the host device, one sensor facing backwards and the other sensor facing forwards.

Another example, the two sensors may be arranged at the battery module. The two sensors may be arranged in/on a top surface of the battery module. For instance, the two sensors may be arranged at opposite sides of the top surface of the battery module. Thereby, there may be a distance between the two sensors. The distance may correspond to a length of the battery module, the distance may correspond to two thirds of the battery module length, the distance may correspond to half the battery module length, the distance may correspond to one third of the battery module length. The two sensors may have different field of views. For examples, one of the two sensors may face backwards and the other one of the two sensors may face forwards. Alternatively, the two sensors may have an overlapping field of view. The two sensors may be arranged at different positions at/in/on the battery module. In some embodiments, the two sensors may be provided adjacent each other, such as adjacent each other in/on a middle part of the battery module, one sensor facing backwards and the other sensor facing forwards

It may be an advantage to have more than one radar sensor, such as two radar sensors, such as three radar sensors, such as four radar sensors, such as two or more radar sensors, to thereby enable use of triangulation to determine user presence. The use of more than one radar sensor can also increase the common field of view, and thus a larger active volume may be monitored. In some embodiments, the powered watercraft comprises at least two radar sensors for redundancy, thereby, even if one radar sensor is not functioning or has decreased functionality, an other radar sensor will still be functioning and the safety of the user will thus not be compromised.

In some embodiments, the at least one radar sensor is a low power radar sensor. The radar sensor may have a power consumption of less than 10 mWatts, such as of less than 5 mWatts, such as of less than 1 mWatts.

In some embodiments, the radar sensor is a high precision, pulsed short-range radar sensor. In some embodiments, the radar sensor footprint is less than 100 mm2, such as less than 50mm2, such as about 30 mm2.

The radar sensor may be operated in the 60 GHz unlicensed ISM radio band. The at least one radar sensor may be operated at about 24 GHz, at about 60 GHz, at about 79 GHz.

When operating at or above 60 GHz, it is an advantage that the radar sensor provides robust performance without interference from noise, dust or direct or in-direct light, such as sunlight.

In some embodiments, the at least one radar sensor has an operational range of between 0,5- 10 meters, such as between 0,5-5 meters, such as between 0,5-2 meters, such as between 0,60 - 2 meters.

According to some embodiments, each radar sensor comprises a radar transmitter and a radar receiver. In some embodiments, the radar sensor may additionally comprise a radio and an antenna, such as a radio and an antenna for communication using Bluetooth, WiFi, Zigbee, etc.

Typically, a radar sensor is configured to emit a radar wave at the selected frequency; when the emitted radar wave hits an object within the 3D field of view of the radar sensor, a portion of the signal is reflected. This can be detected as an echo signal in the radar sensor. Typically, the echo signal has a lower frequency then the emitted signal. The difference between the current frequency and the received frequency is detected by the radar sensor as measured signal. In some embodiments, the radar sensor makes a single measurement, in some embodiments, the radar sensor makes continuous sweeps.

In some embodiments, the radar sensor is a micro-radar sensor, such as a radar sensor based on micro-radar sensor technology. In some embodiments, a detection angle, such as a field of view, for the radar sensor may be up to 60 degrees, such as up to 50 degrees, such as up to 40 degrees. In some embodiments, the detection angle for the radar sensor may be between 30 and 50 degrees. In some embodiments the detection angle (or field of view) is specified as Half Power Beam width, HPBW, whereas outside of the field of view the output effect is decreased with at least 3dBm.

In some embodiments, the number of radar sensors and the positioning of the radar sensors may be determined by the desired active volume, or the desired accuracy in dependence on the field of view of the radar sensor, or in dependence of the detection angle for the radar.

In some embodiments, the at least one radar sensor is configured to detect materials with different dielectric constants.

In some embodiments, the radar sensor may distinguish a person and an object using a determined shape of an object. According to some embodiments, the powered watercraft comprises a processor for processing the received radar sensor signals to distinguish between an object being present within the active volume and a person being present within the active volume.

In some embodiments, the at least one radar sensor may distinguish between an element, such as a body part, a foot, a piece of clothes, etc., covering the radar sensor and water covering the radar sensor, such as when the radar sensor is submerged in water. In some embodiments, the at least one radar sensor is configured to detect presence of a user both through proximity and through a blocked radar sensor, e.g. when an element, such as a foot, covers the radar, i.e. when the user/rider happens to stand on the at least one radar sensor.

In some embodiments, the powered watercraft comprises one or more additional sensors, such as one or more of a gyroscope, an accelerometer, a GPS sensor, an rpm sensor, etc. In some embodiments, the processor receives the radar signals and additionally receives output signals from one or more of the additional sensors. The processor may determine presence or absence of a user based on both the radar signals and the output signals from the one or more of the additional sensors.

In some embodiments, the powered watercraft comprises a processor for processing the received radar sensor signals to determine presence of a token, the token being a user token to be carried when operating the powered watercraft. According to some embodiments, the token comprises at least one significant material, the significant material having a characteristic profile when processing radar sensor signals. In some embodiments, the characteristic profile comprises a characteristic dielectric constant.

It is an advantage of being able to detect a token being carried by the user, such as a wearable token, as the at least one radar sensor, the control unit and the processor can be configured to particularly to detect the token. This may in some instances provide a more simple processing of radar sensor signals, as only presence or absence of the at least one significant material needs to be determined.

In some embodiments the radar sensor comprises the processor, in some embodiments the processor is provided in the driveline, in some embodiment the control unit comprises the processor.

In some embodiments, the control unit receives processed radar sensor signal from the processor, and determines to terminate power to the propulsion unit based on the received processed radar sensor signals.

In some embodiments, the at least one radar sensor is based on pulsed coherent radar technology.

According to some embodiments, the processor is configured to determine a mass of a user based on the received radar sensor signals.

According to some embodiments, the control unit is configured to control one or more driveline parameters based on the determined mass of a user, the driveline parameters including battery capacity, amount of power provided to the propulsion module, motor current, maximum motor current, motor rpm, maximum motor rpm and throttle curve parameters.

According to some embodiments, the control unit is configured to receive radar sensor signals from the at least one radar sensor and to determine user gestures based on the radar sensor signals.

According to some embodiments, the control unit is configured to control driveline performance based on the determined gestures, driveline performance including increase of speed or decrease of speed of the powered watercraft. According to some embodiments, the control unit is configured to control driveline parameters based on the determined gestures, the driveline parameters including battery capacity, amount of power provided to the propulsion module, motor current, maximum motor current, motor rpm, maximum motor rpm and throttle curve parameters.

In some embodiments, the throttle curve sets 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 is linear, so that, 0% activation of the handle corresponds to a 0% throttle command, 50% activation of the handle corresponds to 50% throttle, 100% activation of the handle (complete de-press) corresponds to 100% throttle, and so on. In some embodiments, throttle curve parameters may be adjusted to adjust this characteristic. For example, a number of parameters, corresponding e.g. to points on the throttle curve, may be set, and the resulting throttle curve determines the response to an activation of the handle.

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 descriptions of the drawings

The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non- limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figs, la-lc shows a powered watercraft according to embodiments of the present disclosure.

Fig. 2 shows an exemplary powered watercraft in more detail.

Figs. 3a-3d shows exemplary powered watercrafts including at least one radar sensor in more detail.

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, la-lc 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 radar sensor 118, wherein the at least one radar sensor 118 has a field of view 128 including at least a part of a user, such as a part of a user operating the powered watercraft, the radar sensor 118 providing radar 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 radar sensor 118, 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. la, the at least one radar sensor 118 may be provided in the battery module 110 and may be powered by the battery module.

As is seen in Fig. lb, the powered watercraft comprises two radar sensors 118 and they may both be provided in the battery module 110 and may be powered by the battery module. As is seen in Fig. lc, the at least one radar sensor may be provided at or in the host device. In some embodiments the at least one radar sensor being provided at or in the host device may be powered by a separate power supply 120.

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 radar sensor 118 and the control unit 104 implements a dead man's switch for the powered watercraft 100.

The powered watercraft may comprise a processor 124 for processing the received radar sensor signals. The processed radar sensor signals may then be provided to the control unit for controlling power delivered to the propulsion unit accordingly. The processor may be provided in the battery module or in the propulsion module. In some embodiments, the radar sensor, such as a radar sensor unit comprises the processor.

In Fig. 2 the host device 102 containing the battery module 110 and the propulsion module (not shown) has an active surface 112, the active surface 112 being configured to support a user 115 during use of the powered watercraft 100. An active volume 114 is defined above the active surface 112, the active volume 114 being configured to accommodate at least a part of a user 115 during use.

The user may carry or wear a token 126. The processor 124 may process the received radar sensor signals to determine presence of the token 126. The token 126 is a user token 126 to be carried when operating the powered watercraft.

The token 126 may comprise at least one significant material, the significant material having a characteristic profile when processing radar sensor signals.

As is seen in Figs. 3a-d, the at least one radar sensor 118 may be provided in the battery module 110. The radar sensor may be integrated in a battery module surface 122, the battery module surface 122 forming part of the active surface 112.

The powered watercraft may comprise one radar sensor as seen in Figs. 3a, 3b and 3d, or the powered watercraft may comprise two or more radar sensors 118 as seen in Fig. 3c. The processor may then use triangulation to determine user presence.

Also, having at least two radar sensors 118 allows for redundancy, as a fail safe measure, so that if one fails, the other sensor will still detect when a user is no longer present. The processor may to distinguish between an object being present at the powered watercraft, and a person being present. the control unit 104 is configured to receive radar sensor signals from the at least one radar sensor 118 and to determine user gestures based on the radar sensor signals. The person skilled in the art realizes that the present disclosure is not limited to the preferred embodiments described above. The person skilled in the art further realizes that modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.