Abstract:
The invention relates to a motorized watercraft with a control device ( 1 ) and with a drive unit ( 30 ) having a water propeller that is driven by an electric motor ( 31 ). The electric motor ( 31 ), an operating unit ( 10 ), a motor controller ( 20 ), a battery controller ( 50 ) and a battery ( 60 ) are placed in a vehicle hull, and the water propeller is mounted in a flow channel in the vehicle hull. In order to connect the controlling components and the components to be controlled by means of a system architecture, a system bus and of a man-machine interface, the invention provides that the operating unit ( 10 ), the motor controller ( 20 ), and the battery controller ( 50 ) are data-connected by means of a communications device controlled by the control device ( 1 ). This enables an, in particular, fail-safe transmission of data, a constant monitoring of the system components, and when required, an emergency shut-down.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a motorized watercraft with a control device and a drive unit, having a screw driven by an electric motor, wherein the electric motor, an operating unit, a motor control device, a battery control device and a battery are arranged in a vehicle body and the screw is arranged in a flow channel in the vehicle body. 
     The invention also relates to a method for operating a control device of a motorized watercraft, having a drive unit with a screw driven by an electric motor, wherein the electric motor, an operating unit, a motor control device, a battery control device and a battery are arranged in a vehicle body and the screw is arranged in a flow channel in the vehicle body. 
     2. Discussion of Related Art 
     A motorized watercraft within the meaning of this invention is a motor-driven watercraft wherein the person steering the watercraft is pulled on or below the surface of the water. The watercraft is used as a propulsion for a swimmer or a diver. Such a watercraft is also known as a wet-diving boat, because the swimmer or diver is not seated in a cabin, or even on the vehicle, but is in direct contact with the water. 
     A motorized watercraft is known from German Patent Reference DE 90 05 333, which has a cylindrical main body, in which the batteries and other control elements are arranged. The electric motor, as well as the screw, are attached to the stern in a ring-shaped body. This watercraft can be used for propelling a small boat, as well as a single person. In this case the flow created by the electric motor and the screw impacts the person to be transported. 
     A motorized watercraft is known from PCT International Publication WO 01/62347. In this case, the user lies on the vehicle body and the screw in the flow channel is driven by an electric motor supplied from batteries so that a water flow is drawn through the flow channel, which extends opposite a running direction of the watercraft. Thus, the water flow is kept away from the user and, with the shape of the vehicle body, can also be directed past the user. This makes swimming and diving with the watercraft easier. In this case a screw, an electric motor and a control device are combined into a unit and housed in the flow channel of the motorized water craft. This results in a substantial simplification regarding the construction and the maintenance of the watercraft. The batteries placed into a separate housing can be easily removed for the charging process and can be replaced by a fresh housing with charged batteries. 
     When used in accordance with its purpose, the watercraft is exposed to fresh and saltwater, temperature changes and exposure to water pressure. If the equipment is used in a rental facility, it is necessary to take special safety measures and differently trained users into consideration. It is necessary to avoid malfunctions of the equipment, which could harm the user, to the greatest extent. 
     SUMMARY OF THE INVENTION 
     It is one object of this invention to provide a watercraft of the type mentioned above but which, based on its system architecture, makes a particularly safe operation. 
     It is a further object of this invention to provide a method for a particularly safe operation of the watercraft available. 
     The object relating to the equipment is attained if the operating unit, the motor control and the battery control devices are brought into a data connection by a communications arrangement controlled by the control device. It is thus possible to achieve that the data transmission is particularly safe from interference, that continuous monitoring of the system components is performed and that an emergency shut-off can be performed when needed. 
     If data transmission contacts and power transmission contacts are combined in a releasable full-load pin-and-socket connector, it is possible to provide a sturdy releasable connection between the battery control and the motor control devices. 
     The system architecture is clear if the controlled communication device has a system bus for data exchange, because identical signals are available in all components and they all become simultaneously effective in case of changes. 
     If the system bus is designed as a two-wire system with bidirectional differential signal transmission, a dependable data transport can be achieved in spite of high medium-frequency currents in the motor control device and the drive unit and the connected electromagnetic interference effects. 
     If the controlled communication device has an RS-485 transmission arrangement, it is possible to use cost-effective standard components. 
     If the operating unit is a bus master, and the motor control and battery control devices are slaved bus devices, it is possible to achieve the data processing unit with a memory can monitor the data traffic and can detect an interruption. An emergency shut-off can be triggered in case of such an error. 
     If a wireless interface is provided for the data exchange between the control device and a service arrangement, it is possible to realize a data connection which is protected against water penetration. 
     A particularly advantageous embodiment provides for the wireless interface to be designed as a bidirectional infrared interface or other optical interface. Many portable computers are equipped with such an interface and thus can be employed for maintaining the motorized water equipment without being retrofitted. 
     If a timed multiplex method with a variable time raster for the transmitter and receiver is provided for the wireless interface, the available bandwidth is optimally utilized for the data traffic. 
     First-time loading of programs into the data processing arrangement and/or the motor control device and/or the battery control device, as well as updating of the programs, is possible without additional measures if the controlled communication device has bootstrap loader software for data transfer via the wireless interface. 
     If access authorization devices are provided for the data transfer via the wireless interface, it is possible to protect the programs against unauthorized access. 
     An embodiment with adaptation options of the operating parameters for trained operators, and extended authorizations for service personnel, provides access authorization for the access to internal parameters, measured values, settings and programming. 
     An embodiment protected against unauthorized opening and/or penetration by water allows the motor control device to have at least one optical sensor and at least one water sensor. 
     If the battery control device has at least one optical sensor and at least one water sensor, the motorized watercraft is protected against electrical malfunctions. 
     If watertight hidden operating elements are arranged on the control device, it is possible to trigger special functions, such as resetting the clock indicating the length of the lease, without opening the watertight sheathing of the equipment. 
     If an acoustical alarm arrangement is provided in the battery control device, it is possible to alert the operator regarding critical operational states, such as excess temperatures in components, or a malfunction. 
     One embodiment is suitable for leasing the motorized watercraft where a time-recording arrangement acts on the drive unit. 
     Maximum diving depth can be matched to the load-bearing capacity of the watertight sheathing of the motorized watercraft, as well as to the capabilities of the operator, if at least one water pressure sensor is arranged in the control device. 
     In a rugged embodiment of the operating element of the motorized watercraft, the operating unit has at least one handle with a hand grip sensor, and the hand grip sensor has a movably seated permanent magnet, which is in operative connection with two magnetic field sensors. 
     Self-monitoring of the operating element, and thus an embodiment of particular functional dependability can be achieved if an error detector by forming a summing signal from the two signals of the magnetic field sensors is provided in the hand grip sensor for the evaluation of the signals from the two magnetic field sensors. 
     One object of the method is attained if data are transmitted between the operating unit, the motor control device and the battery control device by a controlled communication arrangement. This makes possible the monitoring of the components and therefore a particularly dependable operation. 
     An increase in operational readiness by exchangeable batteries, simultaneously along with dependable operations by integrating the battery and an intelligent battery control, can be achieved if the data transfer and the power transmission is performed via a releasable full-load pin-and-socket connector. It is thus possible to transmit, besides the power transmission, also programs to the battery control device and to exchange parameters and data between the operating unit and the battery control device. 
     Dependable functioning is achieved, in case of an interruption of or interference with the controlled communication arrangement of more than 3 seconds, if the battery control device switches off the voltage at the full-load pin-and-socket connector completely. With this an endangerment of the operators, as well as damage to components, is prevented. 
     External electrical safety, as well as the protection of components, is improved with the electric motor stopped, when a maximum of 16 V, along with a current limitation of 500 mA, are switched through by the battery control device to the full-load pin-and-socket connector. 
     Searching for errors, as well as a decision in case of damage claims, is easier because diagnostic information regarding extreme values in connection with at least one of the states of temperature, current and water pressure, as well as at least one of the events of an open equipment, penetrated water, drive malfunction and sensor errors, is stored in the control device. 
     If during the triggering of an emergency stop, a command for the electric motor to stop is sent by the operating unit via the system bus to the motor control device, if the operating unit requests the number of revolutions of the electric motor via the system bus, if in case a number of revolutions greater than zero is detected a power stage of the motor control device is switched off, if in case of a number of revolutions greater than zero subsequently detected the voltage supply to the motor control device is switched off by an emergency shut-off signal, which is independent of the system bus, and then it is possible to achieve an emergency stop of the electric motor by several independent means and that a malfunction is very unlikely. 
     One embodiment, which is simple to operate, but yet satisfies safety regulations, provides for transporting the motorized watercraft with the charging device connected. A signal is output to the battery control device via the operating device, the battery control device checks the charge status of the battery and, with a charge state of more than 10% of maximum capacity, signals an error, and at a charge state of less than 10% the maximum capacity, starts a charging process up to 10% of maximum capacity. 
     If, for transporting the motorized watercraft, a command for changing into a transport mode is transmitted by the operating unit via the system bus to the battery control device, if the battery control device disconnects the operating voltage from the full-load pin-and-socket connector, and if all components in the battery control device, except for a safety controller are cut off from the electric current supply, then it is possible to achieve a safe transport, but the self-monitoring of the battery control device is still maintained. 
     If, in the transport mode, the safety controller monitors the voltage and temperature of the battery, as well as an optical sensor, it is possible when required during an impermissible operational state of the battery, such as excess temperature or a threat of a deep discharge, to issue a warning, and unauthorized opening of the battery control device can be written up. 
     If, in the transport mode, the safety controller monitors the voltage at the charging socket, and if, when connected with a charging device, it places the battery control device into the normal operating mode, the motorized watercraft can be switched from the transport mode into the normal operating mode without additional devices. Emerging from the transport mode takes place when the voltage of the charging device is located within a permissible voltage range. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       This invention is explained in greater detail in view of the exemplary embodiment represented in the drawing FIGURE which is a schematic representation of the control device for a motorized watercraft. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A control device  1  for a motorized watercraft having an operating element  10  and a motor control device  20  controlled by it, which controls and monitors a drive unit  30  with an electric motor  31 , is represented in  FIG. 1 . Via a full-load pin-and-socket connector  40 , the drive unit  30  and the operating element  10  are connected with a battery control device  50 , which controls and monitors the supply of the control device  1  from a battery  60 . 
     The operating element  10  is used for inputting drive commands to the vehicle, which is suitable for operation on or under water, as well as for outputting information to the operator regarding the status of the vehicle. It is also used for the input of data for programs and parameters intended for the control device  1 . 
     The user lies or stands on the vehicle and holds onto a left handle  15  and a right handle  16 . Drive commands are issued by the right handle  16 , which has a hand grip sensor  18 . The hand grip sensor  18  comprises two magnetic field sensors arranged horizontally one behind the other in the traveling direction, and a permanent magnet which is arranged above them and vertically mounted and is suspended from a leaf spring, and has one pole located above the front magnetic field sensor in the traveling direction. The right handle  16  is inclined in the direction toward the operator for a drive order. Thus, the pole of the permanent magnet moves away from the front magnetic field sensor in the direction toward the rear magnetic field sensor. At maximum deflection, it is located directly above the rear magnetic field sensor. During the described movement of the right handle  16 , the magnetic field at the front magnetic field sensor decreases continuously, while it continuously increases at the rear magnetic field sensor. Both signals are conducted to a data processing unit with a memory  14 , which checks them for plausibility and derives drive orders from them. The plausibility check comprises a calculation of the measurement of a total magnetic field at both sensors and a comparison with upper and lower threshold values. If the total magnetic field lies outside of the threshold values, an error is assumed and an emergency stop is caused. The event is entered in the memory of the data processing unit with a memory  14 . 
     If the operator pushes the right handle  16  forward, the energy supply of the drive unit, and thus the speed of travel, is reduced. If the operator releases the right handle  16 , it returns into the front position and the energy supply of the drive unit  30  is switched off which also occurs if the operator leaves the watercraft against his or her will. 
     The operating unit  10  has an LC display  13  for communication with the operator. A water pressure sensor  17  is used for monitoring the diving depth of the equipment. If an adjustable maximum value is exceeded, the drive unit  30  can be temporarily switched off, so that the equipment rises to the lower diving depth because of its own buoyancy. 
     The operating element  10  has two operating element Hall sensors  11  which are arranged hidden, for special functions, which are not to be accessible to the operator. For example, these can be arranged to the left and right of the LC display  13 . If they are activated by associated permanent magnets, a clock indicating the length of the rental can be reset, for example. 
     The operating element  10  communicates with the motor control device  20  and the battery control device  50  via a data bus. For reasons of electrical middle frequency currents possibly occurring in the motor control device  20 , the motor control device  20  and the drive unit  30  are spatially separated from the operating unit  30 , and the system bus is realized by bidirectional differential signal transmission technology, such as RS-485. The operating element  10  acts as the bus master on the bus, and the motor control device  20  and the battery control device  50  as bus slaves. The bus master transmits commands to the slaves and receives an acknowledgement for each query, which again contains the original query. 
     With this the bus master can determine whether a command reaches the slave and is correctly understood and processed. If the bus master detects an error, the user can resend the command or initiate safety measures, such as an emergency stop. 
     A bidirectional infrared interface  70  is installed in the operating element  10 . Thus, it is possible to access the programs in the operating element  10 , the motor control device  20  and the battery control device  50  from the outside, and new programs can be stored, if required. It is also possible to read out parameters from these units, or also write them therein. Bootstrap loader software is provided for this purpose in the data processing unit in the memory  14 . There, authentication of the inputs is also performed by a PIN code. Different levels of authorization are provided for users, service and factory, which permit and block access to programming options and data. The length of lease for leased equipment and the maximum diving depth can also be set through the PIN-secured input. In this case, the maximum diving depth can be changed by the “user” with a PIN to the extent the limits set by the “factory” PIN permit this. The timer can count down after the lease time is set and can thus indicate the remaining length on the LC display  13  to the user. At a preset remaining length of time the output of the electric drive is reduced in order to signal the request for the return to the user in addition to the display, yet to make it possible for the user to return at reduced speed. 
     The commands from the operating unit  10  are passed on to the motor control device  20  via a regulator  22  to a power stage  25 . The power stage  25  is monitored by a temperature sensor  24  and protected against an overload. The power stage  25  is connected with the drive unit  30  via a power transmission device  36  and a data transmission device  37 . 
     The number of revolutions of the electric motor  31  is measured by motor Hall sensors  32  is passed on via the system bus  43  and is compared with desired values by the data processing unit containing the memory  14  in the operating unit  10 . In case of a deviation from desired values, for example if, in spite of a command for reducing the number of revolutions of the electric motor  31  to zero via the system  43 , the number of revolutions of the electric motor  31  does not return to zero, it is possible with the emergency shut-off signal  26 , which acts independently of the system bus  43 , to switch off the entire electric current supply of the motor control device  29  and to achieve the dependable stop of the motor. 
     The temperature of the electric motor  31  is continuously monitored by a temperature sensor  35 , so that an emergency switch-off can take place. 
     With the drive mechanisms shut off, the power stage  25  can be completely switched off as a measure for energy savings. 
     The battery  60  and the associated battery control device  50  can be exchanged in order to provide a continuous readiness of the equipment, and a connection with the system bus is made via the full-load pin-and-socket connector  40  which has, besides two power transmission contacts  42 , two data transmission contacts  41 . Because of the design of the system bus as a serial bus, two data transmission contacts  41  are sufficient, and it is possible to select a particularly rugged plug-in connection with only four contacts. The battery  60  is connected with the battery control device  50  via a power transmission device  57  and a data transmission device  58 . A safety controller  55  monitors the battery voltage and temperature by the temperature sensors  61 ,  62 . In case of a danger of overheating, as well as of a possible deep discharge, the safety controller  55  issues a warning signal via an acoustic alarm device  54 . 
     The safety controller monitors the full-load pin-and-socket connector  40  regarding a possible short circuit caused by saltwater or objects capable of conduction. For this purpose, with the motor stopped, the voltage at the power transmission contacts  42  can be limited to a safe value of 16 V, and the maximum current can be limited. In actual use, a value of 500 mA for the current limitation is proven to be suitable. Driving voltage is switched on as soon as the user operates the hand grip sensor. This is followed by the command from the operating unit for switching on the motor. 
     The safety controller also monitors the full-load pin-and-socket connector  40  regarding a disruption of the data transmission via the system bus  43  and, in case of a disruption of more than 3 seconds, switches off the voltage at the power transmission contacts  42 . 
     The motor control device  20  and the battery control device  50  contain water sensors  23  and  53 , so that in case of leakage of the units this event can be entered in the error memory of the data processing arrangement containing the memory  14  and the drive mechanism can be switched off. In case of water in the battery, an entry is also made in the memory of the battery control device, because the battery can also be operated separately from the operating unit. Thus, it is possible in case of the entry of water to stop operating in a dived state early, before the motorized watercraft sustains more extensive damage. The motor control device  20  and the battery control device  50  contain optical sensors  21  and  52 , which detect the opening of the components and allow its recording in the data processing arrangement containing the memory  14 . In case of water in the battery, an entry is also made in the memory of the battery control device, because the battery can also be operated separately from the operating unit. 
     Unauthorized opening of the equipment can thus be detected and can be used for finding the reason for possible damages. 
     The battery control device  50  can be connected with a charging device, not represented here, via a charging socket  51 . If the safety controller  55  detects a suitable charging voltage at the contacts of the charging socket  51 , the charging process which is monitored by a charging control device  56 , of the battery  50  is started. During this, the safety controller  55  monitors the temperature of the battery  60  by temperature sensors  61  and  62 . Because of the high capacity, a lithium-ion battery is preferably used as the battery. 
     For a transport by air, the full-load pin-and-socket connector  40  must be voltage-free and the charged state of the battery  60  can be at most 10% of its maximum capacity. In preparation, the user can send a signal via the system bus  43  to the safety controller  55  by the operating unit  10  and while the charging device is connected. If the momentary charging state is too high, a warning signal is emitted and the user must discharge the battery down to the permissible limit. If the charging state is below 10%, the battery  60  is charged to 10% of its maximum capacity. Thereafter, the safety controller  55  disconnects the voltage supply from the power transmission contacts  42  and the remaining users. Only the safety controller  55  itself remains active and monitors the voltage and temperature at the battery  60 , as well as the light sensor  52 . The control device  1  is ready to be transported. 
     For terminating the transport mode, the charging device is again connected. If the safety controller  55  discovers a permissible charging voltage, it reactivates the components of the control device  1  and initiates charging of the battery  60  up to a desired capacity. 
     With this system it is possible to achieve a dependable operation, even under critical operating connections, such as electromagnetic interferences, leakage at the full-load pin-and-socket connector  40  or in the housing of the motor control device  20  or the drive unit  30 , and even in an event of a malfunction of the system bus  43 .