Method for operating a flying object and flying object

Abstract

The invention relates to a method for operating a flying object (10), in particular a flying object (10) electrically driven by batteries, and a corresponding flying object (10), the flying object having at least one battery system (12) and at least one at least partially electric drive unit (14). Provision is made for a first power limit of the battery system (12) to be extended to a second power limit of the battery system (12) in an emergency situation, so that the flying object (10) can safely perform an emergency landing.

Description

[0001] The present invention relates to a method for operating a flying object, in particular a battery-electrically driven flying object, which has at least one battery system and at least one at least partially electric drive unit, wherein the battery system has a first power limit, and wherein status data of the drive unit and / or the flying object are recorded.

[0002] Furthermore, the present invention relates to a flying object, in particular a flying object that is electrically driven (or operated) by a battery, which has at least one battery system, at least one at least partially electric drive unit and at least one control unit, wherein the battery system has a first power limit, and wherein status data of the drive unit and / or the flying object are recorded by the control unit.

[0003] Unlike vehicles, flying objects are subject to significantly higher safety requirements. This is due to the increased difficulty of achieving a safe state in the event of a technical malfunction in an aircraft. In the event of a technical malfunction in a vehicle, it is usually possible to immediately shut down technical components, bring the vehicle to a stop, and thereby achieve a safe state. In contrast, flying objects, particularly those without traditional wings, such as multirotors, must land, which often requires high power depending on the flight plan.

[0004] After a technical fault has occurred, a drive power in the range of the maximum power of the drive device in normal operation is still necessary for a relatively long period of time until a safe state is reached.

[0005] Patent document US2005 0187677A1, for example, shows a method for remotely controlling a vehicle and in particular an aircraft, wherein a separate emergency electrical storage device is provided, so that in an emergency a redundant energy storage device is provided for safe operation of the aircraft.

[0006] Patent document DE 10 2014 106 538 A1 discloses a method for operating an aerial vehicle having a battery-powered drive and a battery for powering the drive. In one embodiment, a minimum voltage is specified for the battery, the value of which is selected such that deep discharge occurs below the minimum voltage. According to this method, the voltage must not fall below the minimum voltage, as this could damage the battery.

[0007] Patent document US2013-0320756A1 discloses a method for monitoring an electrical energy storage device in an electrically driven vehicle. It specifies that the electrical energy storage device may occasionally undergo deep discharges. The frequency of these deep discharges is recorded, and if a specific number of deep discharges is exceeded, the possibility of deep discharge is prevented or a warning is issued.

[0008] Patent document DE 10 2011 120 439 A1 discloses a power supply device and a method for controlling the operation of the power supply device. With this power supply device, it is possible to fall below the end-of-discharge voltage, thereby enabling deep discharge of the energy storage device of the power supply device. To prevent damage to the energy storage device, the output current of the power supply device is limited during deep discharge.

[0009] The object of the present invention is to provide a method for operating a flying object and a flying object, wherein components of the drive train can be operated in such a way that safe operation is achieved while reducing costs and / or weight.

[0010] This technical problem is first solved in the present invention by assigning (or configuring) target state data to the state data, and by enabling the first power limit to be extended to a second power limit if the target state data are undershot or exceeded. The flight plan of the flying object can be designed arbitrarily. However, a flight plan with little or no gliding capability is preferred.

[0011] A battery system can be composed of interconnected battery cells (or cells). For example, lithium-ion batteries can be considered. A battery system has a current limit that is defined so that more current can potentially be drawn from the cells. However, this can lead to more rapid damage to the cells. This damage, in turn, can render the cells unusable, shorten their service life, or otherwise limit their functionality.

[0012] The drive unit can be designed to be purely battery-powered, i.e., to have an electric motor as the torque source. Hybrid electric drive units are also conceivable. These drive units can have a battery and fuel cell system associated with the electric motor as the torque source. The additional use of a drive unit based on gaseous or liquid fuels, such as a jet engine or a piston engine, is also conceivable.

[0013] The number of drive trains within a drive unit can be one or more. The connection between the drive train and the thrust-generating components, such as propellers, can be designed arbitrarily. For example, one drive train for one propeller or four separate drive trains for eight propellers are conceivable, wherein each drive train is designed for two propellers.

[0014] The status data can include various data about the aircraft. For example, the propeller speed, the temperature in the interior and exterior of the aircraft, or the available power of the battery system can be mentioned. For example, if the propeller speed drops, this is recorded as a deviation from the target state. A second power limit can then be released or activated for the battery system, at which, for example, a deep discharge of the battery system can be performed.

[0015] The advantage of the present invention is that it provides a technical or operational solution that allows drive train components to be operated beyond their actual available power range and, in an emergency, allows for a safe landing of the aircraft while tolerating subsequent component damage and / or shortened component service life. Batteries in battery-electrically powered aircraft can be particularly useful in such emergency situations.

[0016] The operational use of a battery generally represents a compromise between the power or current limit of the battery and the shortened service life associated with the operation. A higher power release results in a shorter service life.

[0017] However, since a higher power release is generally possible, a special power increase can be implemented for a short period of time. This special power increase can damage the battery, but if, for example, other battery systems required for normal operation fail completely, it ensures the landing of the aircraft. Within the scope of drive train design, this measure can reduce the redundancy requirements of the technology used, and the drive train can be designed to be less complex and extensive. This results in a more cost-effective and lower-mass design, making the solution more energy-efficient. For example, the individual battery systems do not need to be dimensioned to exceed the actual power requirements in terms of their capacity in the event of a system failure.

[0018] The second power limit does not necessarily have to be statically determined. The second power limit can be designed, for example, such that a deep discharge of the battery system cannot yet be performed or can only be performed partially.

[0019] Further preferred embodiments of the present invention result from the remaining features mentioned in the description.

[0020] In a first preferred embodiment of the method according to the invention, provision is made for outputting a recommendation to extend the first power limit to a second power limit if the nominal state data are undershot or exceeded by a first limit value (or threshold value). In this way, it can be indicated to the pilot or, for example, to the control unit that it may be advisable to extend the power limit of the battery system to the second power limit.

[0021] Additionally, another embodiment of the present invention may provide for the first power limit to be extended to the second power limit if the pilot confirms the recommendation. This allows the pilot to make a choice and make their own judgment. For example, if an aircraft sensor malfunctions but the pilot determines that extending the first power limit to the second power limit is unnecessary, the recommendation for power extension need not be followed.

[0022] Alternatively or additionally, another embodiment of the present invention provides for extending the first power limit to a second power limit if the recommendation is confirmed by a monitoring device connected to the aircraft. The monitoring device can, for example, be a ground control center, i.e., an external monitoring device wirelessly connected to the aircraft. This connection can be achieved, for example, via a communication interface, through which all signal quantities arriving at the aircraft's monitoring unit are transmitted at regular intervals, preferably in a bundled manner. The monitoring device can include a monitoring unit with a specific functional scope for evaluating status data.

[0023] Optionally, another person can oversee the monitoring system. Communication between this person and the monitoring system is designed to be similar to communication between the pilot and the device monitoring the aircraft's status data. In an emergency scenario, the monitoring system can send control recommendations to the aircraft. These recommendations flow into the functional blocks of the aircraft's decision-making system. Furthermore, if the aircraft requires a pilot, the monitoring system sends the pilot a situation assessment and operational recommendations, similar to how the aircraft does.

[0024] In an emergency situation, a further embodiment of the method according to the invention can provide for the first power limit to be automatically extended to a second power limit if the nominal state data is undershot or exceeded by a second limit value. This automatically identifies the need for a power reserve because the power demand is significantly higher than expected, for example due to bad weather, or because of a drive unit failure and the resulting drop in efficiency, or because the second energy source in a hybrid drive fails due to a fault. The second limit value indicates an emergency situation, while the first limit value indicates a possible malfunction.

[0025] Furthermore, in a further preferred embodiment of the method according to the invention, it is provided that the extension from the first power limit to the second power limit can be carried out manually by the pilot at any time.

[0026] In general, this provides for prioritizing the various possible actions. This allows for the integration of multiple, potentially conflicting commands. For example, a pilot may accept a proposed action and simultaneously initiate an emergency procedure, or there may be a command from a monitoring system. The respective conflicts are resolved according to a fixed priority rule.

[0027] The aforementioned technical problem is also solved by an aforementioned flying object, in particular a flying object electrically driven by batteries, comprising at least one battery system, at least one at least partially electrically driven drive unit, and at least one control unit, wherein the battery system has a first power limit, and wherein the control unit records status data of the drive unit and / or the flying object. The flying object is characterized in that the control unit assigns target status data to the status data and is capable of extending the first power limit to a second power limit if the target status data are undershot or exceeded. The control unit can cooperate with a data interface of the flying object. To this end, the flying object can have a sensor system that can be responded to by the control unit.

[0028] The flying object can be operated by a pilot. However, it is also conceivable that the flying object is remotely controlled. In this case, the flying object can also be controlled autonomously, for example by artificial intelligence.

[0029] In a first preferred embodiment of the flying object according to the invention, the battery system includes a battery control unit, and after the first power limit has been extended to the second power limit, the battery control unit determines and / or signals a state of the battery system. Based on the determined state, or so-called "state of health," of the battery system, it can be signaled whether a battery replacement is necessary due to a possible use of the battery system beyond the first power limit.

[0030] The battery control unit can also determine whether to prohibit restarting of the battery system after the aircraft has landed, or whether, alternatively, to start the battery system at a possibly reduced usage capacity.

[0031] In a further preferred embodiment of the flying object according to the invention, the battery control unit determines the state of the battery system based on the lowest cell voltage occurring in the battery system. Additionally, the integral of the cell voltage over the time it remains below a conventional end-of-discharge voltage, serving as the second power limit, can be used as an influencing variable.

[0032] Furthermore, in a further preferred embodiment of the flying object according to the invention, it is provided that one of the embodiments of the above-described method can be carried out by the control unit.

[0033] All previous descriptions of the method according to the invention also apply accordingly to the flying object according to the invention.

[0034] The different embodiments of the invention mentioned in this application can advantageously be combined with one another unless otherwise stated individually.

[0035] The present invention will be described below in the following examples with reference to the accompanying drawings. In the accompanying drawings:

[0036] Figure 1 A schematic diagram showing an embodiment of a flying object according to the present invention,

[0037] Figure 2 A schematic diagram showing an embodiment of the method according to the present invention and

[0038] Figure 3 The available cell capacities of a battery system corresponding to an exemplary embodiment of the method according to the invention are schematically shown.

[0039] Figure 1 An aircraft 10 is shown having a battery system 12 and four electric drive units 14 in the form of propellers. The aircraft 10 is wirelessly connected to a monitoring device 16. The aircraft also has a control unit 18 and a battery control unit 20. The battery system 12 has a first power limit and a second power limit. During normal operation, the battery system 12 is operated at the first power limit, and accordingly, the aircraft 10 is operated at the first power limit. During the operation of the aircraft 10, the control unit 18 records state data of the aircraft 10, in particular state data of the drive units 14. These state data are compared with target state data. If these state data deviate from the target state data by a first limit value, the control unit 18 outputs a recommendation to extend the first power limit to the second power limit.

[0040] In this way, the entire discharge process, up to the discharge end voltage, which forms the second power limit, is fully available as the normally available energy content. Reaching the normal discharge end voltage, which serves as the second power limit, is visually displayed to the pilot in the battery control unit 20 and / or monitoring device 16 as 0% SOC, or state of charge. Simultaneously, the battery control unit 20 also visually displays an unavailable reserve of, for example, approximately 15%. The battery control unit can be controlled to enable flight beyond the 0% SOC level in exceptional or emergency situations, such as if the planned landing hub is occupied or blocked. Emergency situations can also include weather conditions requiring an unplanned deviation from the route or requiring the landing approach at the planned hub to be unexpectedly repeated multiple times.

[0041] The battery control unit 20 detects that the battery system's cell voltage has fallen below a limit of, for example, 3V and outputs a warning. However, it neither shuts down nor reduces the power limit. A further deep discharge of 0.5 to 1V provides an energy reserve of up to 20% of the total energy content. After a successful emergency landing, the battery control unit 20 prohibits charging or further discharging of the battery system 12. The battery control unit stores a warning at a suitable location, such as in a fault memory, that an emergency deep discharge has occurred, damaging a cell, and that the battery system 12 needs to be replaced. Alternatively, the state of health (SOH) can be reduced using an aging model, and the battery system 12 can continue to be used if the remaining SOH is still sufficient.

[0042] Figure 2 The method for operating according to the present invention is shown. Figure 1 1 shows a schematic diagram of an exemplary embodiment of a method for controlling an aircraft 10. In step 100, it is detected that the status data of the aircraft 10 or the drive unit 14 do not correspond to previously determined target status data. Step 120 shows a case where the status data deviates from the target status data by a second, higher limit value. In this case, an emergency situation can be considered. Therefore, in step 120, the first power limit is automatically extended to a second power limit, allowing the aircraft 10 to perform an emergency landing.

[0043] Step 160 illustrates a situation where the state data deviates from the target state data by a first limit value. In this case, an emergency situation does not yet exist. Therefore, control unit 18 simply outputs a suggestion in step 180 that it may be appropriate to extend the first power limit to a second power limit. In step 200, this suggestion can be accepted or rejected by the pilot. It is also conceivable for aircraft 10 to operate autonomously without a pilot. Alternatively or additionally, this suggestion can be accepted or rejected by monitoring device 16 or the personnel responsible for monitoring device 16.

[0044] Step 240 indicates that the pilot in aircraft 10 can manually extend the first power limit to the second power limit at any time. Similarly, personnel in monitoring system 16 can manually extend the first power limit to the second power limit. These operational options, surrounded by dashed lines, can be partially implemented in parallel. To this end, the operational priorities are specified in step 260. For example, if the control unit 18's suggestion to extend the first power limit to the second power limit is rejected in step 180 in step 200, but an emergency situation arises in the meantime, the first power limit will ultimately be automatically extended to the second power limit in step 280 according to step 140. This decision is signaled to the pilot.

[0045] Figure 3On the one hand, the conventionally available cell capacity 22 is shown, which is, for example, 19 Ah in the expected current load configuration. In addition, the additional cell capacity 24 can be seen. Here, the discharge capacity can be 6 Ah, which is reduced to the discharge end voltage of the second power limit. If such a deep discharge occurs, the cell must be replaced. The expected effects caused by the deep discharge on the anode side may be, for example, the dissolution of copper from the current collector and the formation of copper dendrites on the carbon anode. The anode may be damaged by cracks. Cracks may also form on the cathode side. In addition, aluminum corrosion on the cathode-side current collector and the resulting contact loss are expected.

[0046] Reference Signs List

[0047] 10 Flying Objects

[0048] 12 battery system

[0049] 14 drive units

[0050] 16 monitoring equipment

[0051] 18 control unit

[0052] 20 Battery control unit

[0053] 22 Regularly available single cell capacity

[0054] 24 additional single pool capacity

Claims

1. A method for operating a battery-electrically powered flying object (10), the flying object having at least one battery system (12) and at least one at least partially electric drive unit (14), wherein: The battery system (12) has a first power limit, wherein status data of the drive unit (14) are recorded, characterized in that rated status data are assigned to the status data and, in the event of undershooting or overshooting of the rated status data, the first power limit is extended to a second power limit, wherein, in the event of undershooting or overshooting of the rated status data by a first limit value, a recommendation for extending the first power limit to the second power limit is output, wherein the first limit value indicates a possible malfunction.

2. The method according to claim 1, characterized in that If the recommendation is confirmed by the pilot, the first power limit is extended to a second power limit.

3. The method according to claim 2, characterized in that If the recommendation is confirmed by a monitoring device (16) connected to the flying object (10), the first power limit is extended to a second power limit.

4. The method according to any one of claims 1 to 3, characterized in that If the nominal state data is undershot or exceeded by a second limit value, an extension of the first power limit to a second power limit is automatically carried out.

5. The method according to any one of claims 1 to 4, characterized in that The extension from the first power limit to the second power limit can be manually implemented by the pilot at any time.

6. A battery-electrically powered flying object (10), comprising at least one battery system (12), at least one at least partially electric drive unit (14) and at least one control unit (18), wherein: The battery system (12) has a first power limit, wherein the control unit (18) records status data of the drive unit (14), characterized in that the control unit (18) assigns rated status data to the status data and is capable of extending the first power limit to a second power limit if the rated status data is undershot or exceeded, wherein the control unit (18) outputs a recommendation for extending the first power limit to the second power limit if the rated status data is undershot or exceeded by a first limit value, wherein the first limit value indicates a possible malfunction.

7. The flying object (10) according to claim 6, characterized in that The battery system (12) has a battery control unit (20), and after the first power limit has been extended to the second power limit, the battery control unit (20) determines and / or signals a state of the battery system (12).

8. The flying object (10) according to claim 7, characterized in that The battery control unit (20) determines the state of the battery system (12) based on the lowest cell voltage occurring in the battery system (12).

9. The flying object (10) according to any one of claims 6 to 8, characterized in that The method according to any one of claims 1 to 5 can be carried out by the control unit (18).

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