Determination of the preferred wireless laser power transmission mode

Abstract

A method for determining a preferred radio power transmission mode is disclosed. Each radio laser power transmission mode defines a combination of at least two laser pulses, each of which has a different wavelength. The method includes receiving an index of power received by a radio power receiver for each of a plurality of test radio power transmissions received by a radio power receiver, each of which radio power transmissions corresponds to a different radio power transmission mode, and determining a preferred radio power transmission mode for at least one of the test radio power transmissions based on the index of power received by the radio power receiver. A corresponding computer program, non-temporary memory, and satellite are also provided.

Description

Technical Field

[0001] The present invention relates to a method for determining a preferred wireless power transmission mode. In particular, the method enables the determination of a preferred wireless power transmission mode based on the current state of a wireless power receiver. Other aspects of the present invention relate to corresponding computer programs, non-transitory memories, and satellites.

Background Art

[0002] Many devices driven by electricity that are not directly connected to a power source such as a satellite have their own built-in power sources such as batteries or solar cells, but this power source may be insufficient in certain situations. In some cases, the built-in power source may not provide sufficient power, and the device may no longer be able to be supplied with power. For example, the battery may run out, or the solar cell may no longer be exposed to sunlight, or the intensity of sunlight may limit the power output.

[0003] In such situations, it is desirable to be able to provide an external wireless power source. This can be done using forms of wireless power transmission. Such forms of wireless power transmission include short-range technologies such as inductive coupling and capacitive coupling using microwaves or lasers, as well as long-range technologies.

[0004] The efficiency of the wireless transfer of power depends in part on the device receiving the wireless power transmission, i.e., the wireless power receiver. Depending on the current state of the wireless power receiver, the optimal mode of wireless power transmission can vary. Little information may be known about the wireless power receiver, and it may not be possible or practical to physically inspect the wireless power receiver to determine its current state. This is particularly true for other celestial objects such as satellites in orbit or extraterrestrial rovers.

[0005] To enable efficient wireless power transmission, it is preferable to have a method for determining a preferred wireless power transmission mode based on the current state of the wireless power receiver. [Overview of the project]

[0006] The present invention is defined in the independent claims. Embodiments of the present invention are described in the dependent claims.

[0007] A first aspect of this disclosure provides a method for determining a preferred wireless power transmission mode. The method includes receiving an index of power received by a wireless power receiver for each of a plurality of test wireless power transmissions received by a wireless power receiver, wherein at least two of the wireless power transmissions correspond to different wireless power transmission modes. The method further includes determining a preferred wireless power transmission mode based on the index of power received by the wireless power receiver for at least one of the test wireless power transmissions.

[0008] According to this aspect of the disclosure, multiple test radio power transmissions are performed according to different radio power transmission modes. This makes it possible to select a preferred mode without knowing in advance any many specific details regarding the radio power receiver in order to optimize the desired characteristics of a future radio power transmission.

[0009] Optionally, each radio power transmission mode defines a combination of at least two laser pulses. In this case, each of the at least two laser pulses varies in one or more characteristics. For example, each of the at least two laser pulses may have at least a different wavelength, a different instantaneous or average power, or a different pulse mode (i.e., continuous, variable power, etc.) from each of the other at least two laser pulses.

[0010] Testing laser pulses with such different characteristics means that a preferred mode can be determined by comparing the received power with the received radio power for each radio power transmission mode. For example, using laser pulses at two power levels or wavelengths can provide a first approximation of the EQE curve, or an indicator of how the radio power transmission mode can be modified to improve radio power transmission. Laser pulses with different pulse modes may, for example, indicate a preferred pulse mode for reducing heating at the power receiver.

[0011] Optionally, each of a plurality of test radio power transmissions is received sequentially by a radio power receiver. Preferably, between each test radio power transmission, the method further includes determining the radio power transmission mode to be used for the next test radio power transmission.

[0012] In this way, the radio power transmission mode to be used in the next test radio power transmission is determined between each test radio power transmission. Preferably, the determination of the radio power transmission mode to be used in the next test radio power transmission is based on a previously received index of the power received by the radio power receiver and at least one of the radio power transmission modes used in the previous test radio power transmission.

[0013] Using at least one previously used radio power transmission mode to indicate the next radio power transmission mode to be tried allows the iterative process to optimize (or significantly improve) the radio power transmission modes for a particular radio power receiver. This means that a preferred radio power transmission mode can be obtained more efficiently than if random radio power transmission modes were tried, using fewer test transmissions and therefore less power to determine the preferred radio power transmission mode.

[0014] Genetic algorithms and / or machine learning may be used to determine the radio power transmission mode to be used for the next test radio power transmission. Genetic algorithms allow for the efficient evolution of radio power transmission modes to find the optimal (or sufficient according to the operating parameters) radio power transmission mode. Machine learning techniques can, in particular, allow for the improvement of the algorithm over time, if the algorithm learns based on the results of each application of the method (between the same radio power transmitter and radio power receiver, or between different radio power transmitters and receivers).

[0015] In some implementations, if the power received from the most recent test radio power transmission is less than or equal to a certain threshold of power received from test radio power transmissions preceding the most recent test radio power transmission, a further radio power transmission mode is not determined.

[0016] In other words, the method can be terminated when the power received by the radio power receiver from a test radio power transmission is less than the power received from a previous test radio power transmission, or when the difference in power received by the radio power receiver from two consecutive test radio power transmissions is within a certain threshold. This provides a means for determining when to stop the test in order to find a preferred radio power transmission mode, that is, when no further improvement, or sufficiently large improvement, is observed.

[0017] Alternatively, or in addition, the number of test radio power transmissions in a series of test radio power transmissions may not exceed a predetermined number. This provides an alternative or additional means for determining when the method should be stopped. This may be preferable when some information about the radio power receiver is known (for example, a reasonably good radio power transmission mode can therefore be determined as a starting point). The number of test radio power transmissions can also be based on the power available for the tests and the average power used for each test (i.e., number of tests = total available test power per test, average power). This can prevent too much power from being used in the process of determining the optimal radio transmission mode.

[0018] Optionally, multiple test radiopower transmissions include one or more initial test radiopower transmissions, each of which corresponds to a predetermined radiopower transmission mode. In this way, the method can begin with a predetermined initial pattern of test radiopower transmissions. For example, the parameters of the radiopower transmission mode being tested can be varied in a predetermined manner in one or more initial test radiopower transmissions. This can provide the advantage of enabling the identification of a good starting point for subsequent iterations of the method. In some cases, the predetermined initial pattern of test radiopower transmissions may be based at least in part on information about the radiopower receiver (e.g., different types of solar receivers may have different predetermined initial patterns of test radiopower transmissions).

[0019] Optionally, this method is configured for use with a radio power receiver equipped with a solar cell. In this case, each radio power transmission mode may include at least several different wavelengths equal to the number of junctions in the solar cell. That is, in the case of a two-junction solar cell, each radio power transmission mode may define a laser pulse containing two lasers, each with a different wavelength. In this way, the radio power transmission modes are more likely to achieve greater radio power transmission efficiency.

[0020] Preferably, each radio power transmission mode may include two or more different wavelengths per junction. This improves the likelihood of finding the optimal wavelength for a given junction and increases the speed of the method. Furthermore, it can allow for approximation of the EQE curve for that junction, and thus even enable a better determination of future radio power transmission modes to be tested, or preferred radio power transmission modes.

[0021] In either case, the wavelength is preferably related to the band gap of the solar cell junction. In this way, when the structure of the solar cell is known, insight-based wavelength selections can be tested to find the optimal wavelength for that particular solar cell. For example, in this case, to determine whether the best practical wavelength is longer or shorter than the theoretical wavelength, wavelengths slightly above the theoretically best wavelength for the solar cell junction and wavelengths slightly below the theoretically best wavelength can be used. This can increase the speed and efficiency of the method.

[0022] Optionally, determining a preferred radio power transmission mode for each test radio power transmission based on an indicator of power received by a radio power receiver includes selecting the radio power transmission mode corresponding to one of the test radio power transmissions as the preferred radio power transmission mode.

[0023] In this implementation, one of the tested wireless power transmission modes is selected as the preferred wireless power transmission mode. This is a relatively computationally simple method for selecting the preferred wireless power transmission mode, and the performance of the wireless power transmission mode is known in advance based on testing.

[0024] Alternatively, determining a preferred wireless power transmission mode for each test wireless power transmission based on an indicator of power received by a wireless power receiver includes estimating an external quantum efficiency spectral response curve for each test wireless power transmission based on an indicator of power received by a wireless power receiver, and determining a preferred wireless power transmission mode based on the external quantum efficiency spectral response curve.

[0025] In this implementation, the results of test wireless power transmission are used to estimate the external quantum efficiency spectral response curve, and the preferred wireless power transmission mode can be determined based on the modeled external quantum efficiency spectral response curve. This is more computationally intensive, but it allows for the determination of a better wireless power transmission mode with fewer tests, saving power and increasing the efficiency of the method. In this case, the preferred wireless power transmission mode may be further determined based on the laser available to the wireless power transmitter.

[0026] Optionally, the preferred wireless power transmission mode is determined using artificial intelligence such as a neural network. Using artificial intelligence such as a neural network can increase the speed and efficiency of determining the preferred wireless power transmission mode, and can increase the likelihood that the preferred wireless power transmission mode is optimal.

[0027] In this case, the artificial intelligence is preferably trained with training data derived from a previous implementation of the Method. Using training data derived from a previous implementation of the Method can lead to a more efficient method over time. For example, the neural network can look at the iterations of the tested radio power transmission modes and the ultimately selected preferred radio power transmission mode to better optimize the iterations to be tried in future implementations of the Method. This can lead to a reduction in the number of radio power transmission modes tested, which can reduce the power used by the Method and increase its speed.

[0028] Optionally, a preferred wireless power transmission mode is a wireless power transmission mode that enables a wireless power receiver to receive maximum power or a specified amount of power. In this case, the method is configured to determine the wireless power transmission mode that delivers the most power, meaning that the most energy can be transferred over the shortest amount of time, or that a specified amount of power can be transferred. In the context of a satellite implementation, for example, it may be beneficial to deliver the maximum amount of power if the satellite passes by for only a short time, while receiving a specified amount of power may be beneficial because it enables the wireless power receiver to operate under preferred conditions (e.g., preferred received power).

[0029] Alternatively, a preferred wireless power transmission mode is a wireless power transmission mode that enables the most efficient wireless transfer of power from a wireless power transmitter to a wireless power receiver. In this case, the method is configured to determine the wireless power transmission mode that delivers power most efficiently, meaning that more power can be transferred in total over a longer period of time (due to fewer losses caused by inefficiencies). Again, in the context of a satellite implementation, this can enable a satellite to provide power to more other satellites for a given amount of power stored, generated, or received at the satellite transmitting the power.

[0030] Alternatively, a preferred wireless power transmission mode is a wireless power transmission mode that enables the most efficient wireless transfer of power from a wireless power transmitter to a wireless power receiver while still providing a threshold (e.g., instantaneous) amount of power or energy. This can ensure that the wireless power receiver receives at least the minimum required amount of power in the most energy-efficient manner.

[0031] Alternatively, a preferred radio power transmission mode is one that allows for the most efficient radio transmission of power from the radio power transmitter to the radio power receiver while still providing a threshold (e.g., instantaneous) amount of power or energy. This is the most energy-efficient method from the perspective of the radio power transmitter, ensuring that the radio power receiver receives at least the minimum amount of power required. This may be beneficial, for example, when the radio power transmitter has only a certain amount of energy to store.

[0032] Alternatively, or as an additional constraint, a preferred radio power transmission mode is one that enables radio power transfer to the radio power receiver without increasing the temperature of the radio power receiver and / or radio power transmitter beyond a threshold amount. In particular, this can be done while still providing a threshold (e.g., instantaneous) amount of power or energy. In this case, the method is configured to determine a radio power transmission mode that minimizes heating of the radio power receiver and / or radio power transmitter and thus reduces the impact on other components or functions of the radio power receiver.

[0033] Alternatively, or as an additional constraint, a preferred radio power transmission mode is one that minimizes the degradation of the radio power receiver and / or radio power transmitter. In particular, this can be done while still providing a threshold (e.g., instantaneous) amount of power or energy. In this case, the method is configured to determine a radio power transmission mode that minimizes the degradation of the radio power receiver and / or radio power transmitter and extends their lifespan.

[0034] Optionally, the method may further include transmitting a test radio power transmission to a radio power receiver for each of several test radio power transmissions.

[0035] Optionally, this may further include wirelessly transmitting power from a wireless power transmitter to a wireless power receiver according to a preferred wireless power transmission mode.

[0036] Optionally, one or both of the radiopower transmitter and / or radiopower receiver are space objects. This method is particularly suitable for cases where one or both of the radiopower transmitter and / or radiopower receiver are satellites, as it allows for the determination of a preferred radiopower transmission mode, taking into account the current state of the radiopower receiver, which cannot be directly inspected, in the case of an orbiting satellite.

[0037] According to a second aspect of this disclosure, a computer program is provided which, when executed, causes a computing system to perform the method of the first aspect.

[0038] According to a third aspect of this disclosure, a non-temporary memory is provided in which a computer program of the second aspect is stored.

[0039] According to a fourth aspect of this disclosure, a satellite is provided that is configured to perform the method of the first aspect. [Brief explanation of the drawing]

[0040] This disclosure is further illustrated by reference to the attached drawings, which are merely examples. [Figure 1] The following are examples of methods according to aspects of the present invention. [Figure 2] Examples of systems capable of implementing aspects of the present invention are provided. [Figure 3] An example of an external quantum efficiency (EQE) spectral response curve is shown. [Figure 4] The following are examples of methods according to aspects of the present invention. [Figure 5] An example of an iterative process according to an aspect of the present invention is provided. [Figure 6] This example illustrates the modeling of the EQE spectral response curve. [Figure 7] This example illustrates the modeling of a different EQE spectral response curve. [Figure 8] The following are examples of systems according to aspects of the present invention. [Modes for carrying out the invention]

[0041] This disclosure relates to a method for determining a preferred wireless power transmission mode for wirelessly transmitting power between a wireless power transmitter and a wireless power receiver.

[0042] Method 100, illustrated in the flowchart of Figure 1, provides a method for determining a preferred wireless power transmission mode. Method 100 enables a preferred wireless power transmission mode, such as the most efficient mode for wirelessly transmitting power, without requiring any knowledge of the wireless receiver (other than the type of wirelessly transmitted power that the wireless power receiver can receive).

[0043] Method 100 begins in step 101 by receiving an indicator of power received by the radio power receiver for each of a plurality of test radio power transmissions received by the radio power receiver. At least two of the radio power transmissions of the plurality of test radio power transmissions correspond to different radio power transmission modes. However, some of the radio power transmissions of the plurality of test radio power transmissions may use previously tested radio power transmission modes, which can improve the certainty of the results obtained.

[0044] The wireless power transmission mode defines the characteristics of the wireless power transmission. The parameters that can be changed will depend on the type of wireless power transmission being used.

[0045] In step 101, once the power indicator received by the radio power receiver for each of the multiple test radio power transmissions, the method proceeds to step 103. In step 103, a preferred radio power transmission mode is determined for at least one of each of the test radio power transmissions based on the power indicator received by the radio power receiver.

[0046] Preferred radiopower transmission can be determined based on different criteria in different operating scenarios. In some cases, a radiopower transmission mode that allows a radiopower receiver to receive maximum power may be determined as the preferred radiopower transmission mode. This can be particularly useful when the transmission period for transferring power wirelessly is limited. This may be the case between satellites in orbit where the satellites are only within each other's line of sight and power transmission range for relatively short periods of time.

[0047] In other cases, the radio power transmission mode that enables the most efficient radio transfer of power from the radio power transmitter to the radio power receiver may be determined as the preferred radio power transmission mode. This can be particularly beneficial when it ensures that energy waste is minimized and when the radio power transmitter has only a finite storage of energy that it can transmit, and / or when the available power transmission time is long.

[0048] In addition to these two examples, other factors that may be considered (in addition to or instead of overall power transmission and power transmission efficiency) include how wireless power transmission affects wireless power receivers and / or wireless power transmitters. For example, when receiving wirelessly transmitted power, wireless power receivers often heat up. This can be undesirable, and therefore, wireless power transmission modes that do not cause the wireless power receiver to heat up beyond a threshold amount may be determined as wireless power transmission modes. This heating can cause degradation in the wireless power receiver, and other factors may similarly cause degradation depending on the wireless power transmission technology used. For example, laser intensity or pulse frequency can cause degradation in the wireless power receiver when a laser is used to transmit power wirelessly. Therefore, wireless power transmission modes that minimize or limit degradation in the wireless power receiver are desirable and may therefore be determined as wireless power transmission modes.

[0049] A preferred wireless power transmission mode may be determined by the number of these factors. For example, a power transmission mode that allows the wireless power receiver to receive the maximum amount of power without overheating beyond a threshold amount may be determined as a preferred wireless power transmission mode. Alternatively, a preferred wireless power transmission mode may be one that allows the most efficient wireless transfer of power from the wireless power transmitter to the wireless power receiver while still providing a threshold (e.g., instantaneous) amount of power or energy.

[0050] A preferred wireless power transmission mode can be simply selected from the wireless power transmission modes tested in step 103 with multiple test wireless power transmissions. This has the advantage that the performance of this wireless power transmission mode is well known. On the other hand, the preferred wireless power transmission mode may be a different wireless power transmission mode from one of the multiple test wireless power transmissions that was tested. In this case, the preferred wireless power transmission mode is determined based on the results of the test wireless power transmissions (e.g., the power received by the wireless power receiver for each test wireless power transmission). For example, a model of the wireless power receiver may be generated based on multiple test wireless power transmissions (e.g., external quantum efficiency spectral response curves, as considered below).

[0051] In some cases, artificial intelligence methods may be used to determine a preferred wireless power transmission mode. For example, a machine learning model, such as a neural network, may determine a preferred wireless power transmission mode based on wireless power modes tested by a series of test wireless power transmissions and the power received by a power receiver for each of these test transmissions. The machine learning model can be trained with data (preferably of the same type of wireless power transmitter and receiver) derived from previous implementations of the method and can be updated each time the method is applied based on a series of test wireless power transmissions.

[0052] In a preferred embodiment, lasers are used as means for wirelessly transmitting power from a transmitter to a receiver. In this case, parameters that may be defined (and vary between test wireless power transmissions) in the wireless power transmission mode include the number of lasers used, the wavelength(s) of the laser(s) used, the power(s) of the laser(s) used, and the pulse mode(s) of the laser(s) used.

[0053] The pulse mode defines whether the laser operates in a constant mode throughout the entire test transmission, or whether the laser's intensity or power changes throughout the entire test transmission (e.g., pulses). For example, over a 5-second test transmission period, the laser may operate for three 1-second pulses evenly distributed throughout the test transmission period with a 1-second gap between each pulse. It should also be noted that different lasers may operate in different pulse modes within a single test radio power transmission. For example, a first laser with a first wavelength may operate at continuous power for the duration of the test transmission period, while a second laser with a second wavelength may operate for three discrete pulses evenly distributed over the test transmission period.

[0054] In this context, laser power can refer to either the instantaneous power the laser is operating at a given time or the average power over a test transmission period (i.e., the total energy transmitted by the laser during the test transmission period divided by the duration of the test transmission period). These can be related via the laser's pulse mode. For example, the laser in the previous example, operating with three 1-second pulses, may operate at a constant instantaneous power of 50W while on. The average power, then, over a 5-second transmission period, would be (3 × 50) / 5 = 30W, since the laser operates at 50W for a total of 3 seconds. This is the same average power as a laser operating at 30W continuously over the entire duration of the test transmission period. Both of these power measurements can vary between different power transmission modes.

[0055] When determining a preferred mode for wireless power transmission via a laser beam, each wireless power transmission mode should preferably define a combination of at least two laser pulses. Each of the two laser pulses in a wireless power transmission mode should vary in one or more parameters or characteristics of the wireless power transmission mode, such as those considered above. For example, the laser pulses can vary in their wavelength, instantaneous or average power, and / or pulse mode.

[0056] Figure 2 illustrates an exemplary system 200 for wirelessly transmitting power using a laser. System 200 includes a pair of satellites 201 and 203. Both satellites 201 and 203 are in orbit around the Earth 205. Light from the sun is represented by arrow 207. As can be seen in Figure 2, the first satellite 201 is illuminated by sunlight 207. However, the second satellite 203 is in the shadow 209 of the Earth 205 and is therefore not illuminated by sunlight 207. Thus, the solar cell 213 on satellite 203 cannot generate electricity, unlike the solar cell 211 on satellite 201 which is in sunlight 207. However, to overcome this, satellite 201 can wirelessly transmit power to satellite 203. This is illustrated by the dotted arrow 211 in Figure 2.

[0057] Different photovoltaic technologies generate electricity according to the electronic bandgap and surface coating of the photovoltaic material, and the surface coating controls the wavelength of light it interacts with. This can be illustrated as an EQE (External Quantum Efficiency) spectral response curve 300, as illustrated in Figure 3. The EQE of a solar cell is the ratio of the number of charge carriers collected by the solar cell to the number of incident photons of a given wavelength. As can be seen from the illustrative EQE curve 301 in Figure 3, the external efficiency of a solar cell varies depending on the wavelength of received light, based on the bandgap and thickness of the solar cell. Thus, solar cells can convert incident light energy of different wavelengths into electrical energy with different efficiencies. Different solar cells have different theoretically optimally efficient wavelengths of incident light for obtaining electricity.

[0058] However, the practical efficiency of a solar cell can vary with age and temperature, among other potential factors such as environmental factors, coatings on the solar cell, and the angle of incidence of the irradiated light. The effects of these factors can be represented on the EQE spectral response curve by shifts and / or modifications of the EQE curve, exemplified by EQE curve 303, which represents a change from the theoretical EQE curve 301. As can be seen in EQE spectral response curve 300, the modified EQE curve 303 has a different wavelength response compared to EQE curve 301. In particular, the wavelength that yields the highest efficiency for EQE curve 303 is different from the wavelength that yields the highest efficiency for EQE curve 301.

[0059] While it may be possible to predict how the actual EQE curve for a solar cell will differ from the theoretical EQE curve, this is often extremely difficult because the exact conditions and history of the solar cell may not be known. This is especially true for solar cells in space or on space objects such as satellites 201 and 203. Furthermore, it may not be possible to know all the factors that can change the EQE of a solar cell. Therefore, simply using the theoretical EQE curve of a solar cell that is a radio power receiver is insufficient to transmit power wirelessly from satellite 201 to satellite 203 with optimal efficiency. In fact, in some cases, the structure of the radio power receiver may not even be known, and therefore, it is entirely impossible to determine the theoretical EQE curve. Other factors such as temperature, environmental influences such as intervening particles or dust, particles or dust coating the radio power receiver, coatings on the solar cell, and the angle of incidence of the irradiation light can also affect how well the radio power receiver can convert the received radio power into electrical energy.

[0060] Method 100 disclosed in Figure 1 can enable the determination of a preferred wireless power transmission mode that essentially takes all of these factors into account.

[0061] In some cases, the method used to determine the preferred wireless power transmission mode may be an iterative process. Figure 4 illustrates method 400. Method 400 is similar to method 100 shown in Figure 1, but breaks down step 101 of method 100 into several substeps 401-409.

[0062] Method 400 begins with step 401, where the radio power transmission mode is determined. This is the radio power transmission mode that is tested using a test radio power transmission from the radio power transmitter to the radio power receiver.

[0063] As will soon be considered in more detail, Method 400 includes repeating components, and therefore the radio power transmission mode determined in step 401 may be based on previous iterations of the repeating portion of Method 400 (i.e., steps 401-409). However, in the case of the first iteration of these steps 401-409, the radio power transmission mode must still be determined in step 401 in order to initiate Method 400, without the possibility of information derived from previous iterations.

[0064] In this case, the initial radio power transmission mode determined in step 401 may use other information, such as any knowledge of the radio power receiver. For example, if the radio power receiver is a solar cell and the radio power transmitter is configured to transmit power wirelessly using a laser, the initial radio power transmission mode may be determined based on the structure of the solar cell, and in particular, its theoretical band gap may be matched to the wavelength of a laser available to the radio power transmitter.

[0065] The initial radio power transmission mode may also be a pre-configured radio power transmission mode, or it may be selected from a list of pre-configured radio power transmission modes based on some knowledge of the radio power receiver. In this case, the initial radio power transmission mode may be configured to provide the best starting point. For example, it may be a radio power transmission mode that provides most of the information about the receiver to use when determining the subsequent radio power transmission mode for performing subsequent tests among several test radio power transmissions.

[0066] Next, in step 403, a test radio power transmission is transmitted. This test radio power transmission is a radio power transmission that follows the radio power transmission mode determined in step 401, and is transmitted from the radio power transmitter to the radio power receiver.

[0067] This test wireless power transmission is received by the wireless power receiver in step 405, and in step 407, the power index received by the wireless power receiver from the test wireless power transmission is received by the device performing the determination step 409 (which may be the wireless power receiver itself, the wireless power transmitter, or another device or cloud computing system).

[0068] In step 409, it is determined whether to test a different radio power transmission mode. That is, it is determined whether a different test radio power transmission should be transmitted from the radio power transmitter to the radio power receiver according to a different radio power transmission mode than any of the modes tested so far. If a different radio power transmission mode is tested, the method returns to step 401, which determines the radio power transmission mode to be tested in the next test radio power transmission. If no further radio power transmission modes are tested, the method proceeds to step 103, which determines a preferred radio power transmission mode (according to the scheme considered with respect to method 100). If a preferred radio power transmission mode is determined in step 103, the method may optionally include an additional step of transmitting power from the radio power transmitter to the radio power receiver according to the preferred radio power transmission mode.

[0069] Whether to test another radiopower transmission mode in step 409 may be based on a different number of criteria. In some cases, the method may test a set number of radiopower transmission modes. For example, 6, 8, or 10 radiopower transmission modes may be tested (all or some of the radiopower transmission modes to be tested may be predetermined). If a set number of radiopower transmission modes have already been tested in step 409, the method proceeds to step 103; otherwise, the method returns to step 401.

[0070] Alternatively, a minimum number of radiopower transmission modes may be tested. This minimum number may correspond to an initial set of radiopower transmission modes to be tested, and once the initial set of radiopower transmission modes has been tested, the method may, in step 409, determine whether or not to test further radiopower transmission modes (for example, according to the following criteria). The initial set of radiopower transmission modes may be a predetermined set of radiopower transmission modes that have been found to provide an efficient method for collecting useful data about a radiopower receiver, and may, in particular, be based on the details of the radiopower receiver (e.g., its structure), if known. That is, different initial sets of radiopower transmission modes may be used for different radiopower receivers. Alternatively, a random selection of radiopower transmission modes may be used in the initial set of radiopower transmission modes, which may be an effective method for collecting useful data about a radiopower receiver, in particular when little or no information about the radiopower receiver is known.

[0071] In some implementations, other criteria may be considered. In particular, the results of one or more previous test radio-power transmissions may be considered. For example, the method may continue testing radio-power transmission modes until an optimal mode is determined. An optimal mode may be one that is considered "good enough" according to one or more operating parameters (e.g., a specific threshold efficiency, such as 75% of the theoretical maximum efficiency for converting energy transmitted from the radio-power transmitter into electrical energy by the radio-power receiver).

[0072] An optimal mode may be considered determined when the difference in received power between two or more consecutive test radio power transmissions (determined in step 407) is negative (i.e., less power is received from a test radio power transmission than from a preceding test radio power transmission or a preceding defined number of test radio power transmissions). Alternatively, an optimal mode may be considered found when the difference is less than a threshold amount, for example, when the increase in received power between a first test radio power transmission and a second test radio power transmission is less than a threshold amount.

[0073] Other factors may also be considered. For example, a certain amount of energy may be reserved to determine a preferred radio power transmission mode, and therefore, if this amount of energy is consumed during the test radio power transmission (or if an amount of energy within a certain limit is consumed), the method may proceed from step 409 to step 103.

[0074] Combined approaches may also be used. For example, this method may continue testing the wireless power transmission mode until the "optimal" power transmission mode is determined, or until a set number of iterations have been performed.

[0075] Due to the iterative nature of steps 401-409, it is crucial that the results of each test radio power transmission be correctly correlated to the radio power transmission mode being tested. To enable this, a "cue flash" may be implemented. This can be implemented as a pattern of laser flashes indicating the start of a test radio power transmission. This also ensures that the results of background or random illumination are not mistaken for test radio power transmissions. The cue flash is used to initiate the test, as well as can be included throughout the test at predefined locations (e.g., every four test radio power transmissions) to ensure that the received power indicators continue to match the correct test radio power transmissions.

[0076] In some cases, this cue flash may also indicate which radio power transmission it belongs to. For example, a first test radio power transmission may have a first cue flash laser pattern, a second test radio power transmission may have a second cue flash laser pattern, and so on. This can be particularly useful when the radio power transmission mode is being tested according to a set pattern, rather than being iteratively updated for each subsequent test radio power transmission based on the results of previous test radio power transmissions. This allows all test radio power transmissions to be performed rapidly and sequentially, while enabling the power received from each test radio power transmission to be individually identified.

[0077] In each iteration, step 401, which determines the radio power transmission mode to be tested in a subsequent test radio power transmission, may be based in part on the results of a previous test radio power transmission. This may allow for a more efficient determination of a preferred radio power transmission mode for a given set of criteria. A genetic algorithm can be used in this regard, which can vary the parameters of the radio power transmission mode for a subsequent test radio power transmission in order to optimize the radio power transmission mode based on a previous test radio power transmission.

[0078] In some preferred implementations of Method 400, the results of at least two previous test radio-power transmissions may be used when determining the radio-power transmission mode in step 401. For example, in one scenario, the criterion to be optimized is the amount of energy transferred (i.e., the preferred radio-power transmission mode is one that allows the radio-power receiver to receive the maximum amount of energy from the radio-power transmission). If increasing a given parameter of the tested radio-power transmission mode increases the power received by the radio-power receiver, then this parameter may be further increased for a third test radio-power transmission to see if this again further increases the power received. If so, the parameter may be further increased for a fourth test radio-power transmission (and so on) until the power received by the radio-power receiver no longer increases as the parameter is increased. In this case, further tests may be performed by varying the parameter around the value found to have given the highest power received in the tests.

[0079] This iterative process is illustrated by graph 500 in Figure 5. Graph 500 plots a curve 501 showing how the received power changes with an arbitrary parameter. Figure 5 shows how the received power changes with a single parameter, and is therefore illustrated as curve 501. However, in practice, multiple parameters can be investigated, in which case curve 501 may be a multidimensional surface.

[0080] In reality, the relationship between the parameter and the received power is not known, and the purpose of the iterative process is essentially to determine the maximum value of this curve (or surface for multiple parameters). The first test wireless power transmission can be performed with a parameter having a value a, giving a received power of α. The second test wireless power transmission is performed with a parameter having a value b (where b > a), giving a received power β of the receiver (where β > α). As the parameter is increased, the received power increases, so the third test can be performed by increasing the parameter to c (where c > b), giving a received power γ (where γ > β). Again, this increase in the parameter results in an increase in the received power, so the parameter can be increased again in the fourth test wireless power transmission. The fourth test wireless power transmission tests the parameter at a value d (where d > c). However, for the parameter having the value d, the received power is δ (where δ < γ). Therefore, it can be predicted that further increasing the parameter will lead to a decrease in the received power. Instead, a further test can try a parameter value e (where c < e < d). This gives a received power of ε (where δ < ε < γ). Thus, the value e is better than the value d, but still worse than c. The next test can test a parameter having a value between c and e, or between b and c (since it is not necessarily known on which side of the peak c it is). However, it should be understood that when using an iterative approach, the uncertainty of the system should be taken into account. For example, if the difference between the received powers ε and γ is less than the uncertainty of the received power, it cannot necessarily be determined that e is not the optimal value of the parameter compared to c. Rather, both parameters can be considered optimal, or further tests should be performed.

[0081] This is merely one example of a simple iterative optimization process, illustrating how subsequent tests use information from preceding tests to converge to an optimal solution. Many more advanced techniques are known in the art and can be applied to this method, and this method is not limited to that. In particular, as mentioned above, genetic algorithms have been found useful in informing how to change the parameters of a radio power transmission mode between tests to optimize one or more parameters of the radio power transmission mode.

[0082] Other techniques may be used, either alone or in combination, to enable the determination of the optimal mode. In some cases, this method may be initiated by varying the parameters of the radio power transmission mode in subsequent test radio power transmissions in a set manner. This may provide a suitable starting point for a genetic algorithm or other iterative approach. For example, this may help find a global maximum value, rather than just a local maximum value, of a desired output criterion.

[0083] As discussed above, Figure 5 illustrates how the received power can vary with arbitrary parameters. Several different parameters, such as laser wavelength, laser intensity, and pulse mode, may be tested to enable the determination of a suitable and preferred radio power transmission mode. In this case, curve 501 may actually be a surface with dimensions equal to the number of parameters being tested. These parameters may be tested simultaneously (i.e., multiple parameters may change between different iterations of steps 401-409 in Figure 4) or somewhat independently (i.e., steps 401-409 may be repeated to determine the optimal value of each parameter one at a time before moving on to the next parameter). However, this is less desirable because the parameters may not be independent, and therefore, a change in one may change the optimal value of another.

[0084] In addition to using the iterative method described above, this method can utilize knowledge of radio power receivers. For example, as considered above, a solar cell has an EQE that can describe how much power is received from a laser at different wavelengths (e.g., as described with respect to Figure 3). Testing different wavelengths within a single test radio power transmission or across different test radio power transmissions can make it possible to obtain an estimate of the EQE spectral response curve for a solar cell. Different wavelengths can be tested in a single test radio power transmission in which multiple lasers are used within the test radio power transmission.

[0085] Figure 6 illustrates a simple exemplary means in graph 600 of how the EQE spectral response curve 603 for a single-junction solar cell can be reconstructed from multiple test radio-power transmissions. In this case, five test radio-power transmissions were performed at five different wavelengths. For each test radio-power transmission, the power received by the radio-power receiver could be recorded, and the results were plotted as points 601 on graph 600. The EQE curve 603 could then be fitted. This fitting may take into account the expected characteristics (e.g., shape) of the EQE curve.

[0086] This is merely an illustrative example of the principle, and it should be understood that in practice, more complex modeling techniques can be used to model the EQE spectral response curve based on test radio power transmission results. In particular, this illustrative example models the EQE curve for a single-junction solar cell. For multi-junction solar cells, the spectral response curve becomes more complex.

[0087] For example, Figure 7 shows graph 700 illustrating the EQE spectral response curve for a typical solar cell with two junctions. Here, we can see how the two individual spectral response curves 703a and 703b for each junction interact to provide the overall EQE spectral response of the solar cell. This EQE spectral response can be estimated in much the same way as discussed above in relation to Figure 6 by plotting point 701 based on the results of test radio power transmissions. However, it should be noted that if the two spectral response curves 703a and 703b match, the resulting curve may have a steep slope corresponding to the high sensitivity of the solar cell's EQE response to small changes in the wavelength of the incident light. Therefore, it may be beneficial to test more radio power transmission modes configured to probe the EQE curve at wavelengths that are less sensitive to wavelength changes than wavelengths that are less sensitive to wavelength changes.

[0088] Generally, for determining a favorable wireless test power transmission, a small wavelength perturbation between two test modes can allow the slope of the EQE spectral response curve to be determined (at least whether it is positive or negative). This can help determine where the peak of the EQE spectral response curve lies.

[0089] Furthermore, it should be noted that in the case of multi-junction solar cells, the power of lasers at different wavelengths becomes more important, providing another dimension that needs to be included in the model when determining the preferred wireless power transmission mode. That is, it may be desirable to test the same wavelength at different power levels (and / or pulse modes).

[0090] The advantage of modeling the EQE spectral response curve for a solar cell using this method or another method is that this EQE spectral response curve better reflects the current state of the solar cell, taking into account solar cell degradation and other influences that may have caused deviations from the theoretical EQE curve, compared to a theoretical EQE spectral response curve. Furthermore, modeling EQE means that a better estimate of the preferred radio power transmission mode can potentially be determined using fewer test radio power transmissions. Also, once the EQE curve is modeled, the optimal power transmission mode can be calculated from it (which avoids the need for a very large number of iterations of the method to target the optimal power transmission mode).

[0091] Many solar cells, particularly for space or extraterrestrial applications, utilize two or more types of semiconductor materials in what are known as multi-junction cells, for example, by using multiple junctions made from different semiconductor materials. Each of these junctions has a different band gap and therefore responds to light of different wavelengths. To ensure that such multi-junction solar cells can efficiently receive power, it is important that all of these junctions are "operated," that is, that they receive light with wavelengths corresponding to the band gap of each junction. In sunlight, this is not a problem because the sun radiates as a nearly blackbody across a broad spectrum. However, when illuminated by a laser at only specific wavelengths, this can lead to a significant decrease in the efficiency of the solar cell. Furthermore, the optimal wavelength required for each junction can change based on factors such as temperature and aging.

[0092] To wirelessly transmit power to a multi-junction solar cell, the wireless power transmitter preferably comprises several lasers of different wavelengths. These lasers may have wavelengths relevant to the bandgap of the junctions of commonly used multi-junction solar cells. The wireless power transmission mode can define several combinations of these lasers being activated. The lasers to be activated may be based on knowledge of the wireless power receiver (e.g., its structure, manufacturer, or model, and therefore which laser is most likely to best match the relevant bandgap). Alternatively, if nothing is known about the structure, the wireless power transmission mode may include a defined subset of lasers available for testing during a test wireless power transmission. Subsequent test wireless power transmissions may test wireless power transmission modes including different combinations of lasers, allowing for the determination of the best laser for transmitting power to a particular wireless power receiver.

[0093] At a minimum, it is desirable to have at least one laser for each junction of the radio power receiver. For example, if the radio power receiver is a two-junction solar cell, the preferred radio power transmission mode must define at least two lasers of different wavelengths to be used, one corresponding to the band gap of each junction. Otherwise, it is impossible to suitably operate both junctions with laser light, and only very poor power transfer efficiency will be obtained. If the structure of the solar cell is known, during the test phase (e.g., step 301 of method 300), each radio power transmission mode to be tested can specify multiple lasers, each having a wavelength targeting one of the band gaps. The characteristics of these lasers (e.g., power, pulse mode, etc.), or even the lasers used (i.e., using lasers of different wavelengths), can be varied between subsequent test radio power transmissions to enable the determination of the preferred radio power transmission mode.

[0094] However, more preferably, two or more lasers (of different wavelengths) can be defined per junction in the radio power transmission mode being tested. While this may require using more power, a more complex and larger radio power transmitter (e.g., using more available lasers), using two or more lasers per junction provides more information about the current state of the solar cell and how the solar cell's EQE has changed from the theoretical value over its lifetime. This can mean that fewer radio power transmission modes need to be tested to determine a favorable radio power transmission mode. It also means that a better model of the EQE curve of the radio power receiver can be formed, which can enable both faster determination of a favorable radio power transmission mode (i.e., fewer test transmissions) and determination of a more favorable radio power transmission mode (i.e., better optimized for desired characteristics such as the total energy transmitted or the efficiency of the transmitted energy). Note that the wavelength for each junction does not need to be unique. For example, in the case of a radio power receiver which is a solar cell with four junctions, six different wavelengths could be used. In this way, each junction can have two wavelengths targeting it, and some wavelengths target multiple junctions. This can be considered as 1.5 wavelengths per junction. In a preferred example, two or more lasers are used per junction.

[0095] It has been found that it is important to consider the laser power, as well as how the laser wavelength defined in the radio power transmission mode interacts with the solar cell radio power receiver. It has also been found that the laser power corresponding to each junction must be properly balanced in order to match the wavelength of the laser used for the junction bandgap and to provide overall optimal efficiency in converting the received laser light into electrical energy. Individual junctions must not be "overloaded"; that is, the corresponding laser must not be too powerful compared to the lasers corresponding to other junctions, otherwise an overall decrease in efficiency will be observed. Therefore, it is also beneficial to test different wavelengths in multiple test radio power transmissions and to vary the laser power used to determine the optimal balance of power across different wavelengths. In a similar manner and for similar reasons, the pulse mode can also be varied across multiple test radio power transmissions.

[0096] The methods described herein can be implemented in many different configurations in many different contexts. Figure 8 illustrates a schematic diagram of a system 800 configured to implement the methods described herein.

[0097] System 800 comprises a wireless power transmitter 801, a wireless power receiver 803, and a processing system 805. The wireless power transmitter 801 and the wireless power receiver 803 may be, for example, satellites 201 and 203 in Figure 2, respectively. The wireless power transmitter 801 is capable of wirelessly transmitting power to the wireless power receiver 803 (dotted line 807). The wireless power receiver 803 communicates with the processing system 805 (line 811), which can receive an indicator of the power received by the wireless power receiver 803 for the wireless power transmission 807 from the wireless power receiver 803.

[0098] The processing system 805 also communicates with the radio power transmitter 801 (line 809). The processing system 805 can determine the radio power transmission mode to be tested and transmit it to the radio power transmitter 801. This may be based in part on the power indicators received by the radio power receiver 803 for previous test radio power transmissions. The processing system 805 may also determine a preferred radio power transmission mode based on the power indicators received by the radio power receiver 803 for multiple test radio power transmissions. The preferred radio power transmission mode may then be transmitted from the processing system 805 to the radio power transmitter 801. The processing system 805 may also determine whether to continue testing further radio power transmission modes.

[0099] In some implementations, the processing system 805 may be separate from the wireless power transmitter 801 and the wireless power receiver 803 (represented by the dashed circle 813). In this case, it may be implemented on a separate computer or computer network, or in the cloud or other suitable computing environment. Alternatively, the processing system 805 may be part of a wireless power transmitting device 815 that includes both the wireless power transmitter 801 and the processing system 805. In this case, the wireless power transmitting device 815 communicates with the wireless power receiver 803. As yet another alternative, the processing system 805 may be part of a wireless power receiving device 817 that includes both the wireless power receiver 803 and the processing system 805. In this case, the wireless power receiving device 817 communicates with the wireless power transmitter 801.

[0100] It will be understood that the steps of the method described herein may be performed by different parts of system 800, depending on how system 800 is configured. In particular, it depends on whether processing system 805 is a separate processing system 813 from the radio power transmitter 801 and radio power receiver 803, whether processing system 805 is part of the radio power transmitting device 815, or whether processing system 805 is part of the radio power receiving device 817.

[0101] Referring to method 400 in Figure 4, it will be understood that step 403, which involves transmitting a test radio power transmission from the radio power transmitter 801, must be performed by the radio power transmitter 801. Similarly, step 405, which involves receiving the test radio power transmission at the radio power receiver, must be performed by the radio power receiver 803. Processing steps including step 401, which involves determining the radio power transmission mode; step 407, which involves receiving an indicator of power received at the radio power receiver; step 409, which involves determining whether to test a different radio power transmission mode; and step 103, which involves determining a preferred radio power transmission mode, are performed by the processing system 805. Thus, these steps may be performed by a radio power transmitting device 815 incorporating the processing system 805; a radio power receiving device 817 incorporating the processing system 805; or a processing system 813 separate from both the radio power transmitter 801 and the radio power receiver 803. Accordingly, the applicant reserves the right to assert that each of the described configurations is performed by the entire system or by any component thereof.

[0102] As previously stated, the method described herein is particularly beneficial in the space sector. The method can provide a means for determining a more optimal mode for transmitting power between two satellites compared to previous methods, enabling higher power throughput and more efficient power transfer. Furthermore, the ability to determine a preferred radio power mode does not necessarily depend on any action from the radio power receiver other than transmitting an indicator of power received from each test radio power transmission. This is an essential function for existing satellites for control and diagnostic purposes, etc. Therefore, the method can be applied retrospectively to enable optimized power transmission to satellites already in orbit. However, in one embodiment, the satellite acting as the radio power receiver is equipped with a specific module including a processing system 805, which performs processing steps and notifies the radio power transmitter of which radio power transmission modes should be tested and what the ultimately determined preferred radio power transmission mode is. This reduces the computational load on the radio power transmitter satellite, making it easier for it to serve more radio power receiving satellites.

[0103] In other implementations, the processing system 805 can be integrated into a module of a radiopower transmitting satellite. This may be beneficial as it allows for backward compatibility with radiopower receiving satellites that do not have a module capable of meeting the requirements of the processing system 805, as described above. Having the processing system 805 on a radiopower transmitting satellite has the advantage of not relying on communication via a ground station, compared to placing the processing system 805 on the ground, as it may be delayed due to longer flight times, more susceptible to interference due to weather and other factors, and have more limited bandwidth due to regulatory requirements. On the other hand, placing the processing system 805 on Earth (or, in practice, on a separate entity where the radiopower receiving and transmitting satellites may be in orbit) means that it becomes easier to increase the available computing power and to enable a single processing system 805 to service multiple radiopower transmitting satellites (while maintaining the same backward compatibility advantage as placing the processing system 805 on a radiopower transmitting satellite). As another alternative, the processing system 805 may be located in orbit but separate from the radiopower transmitter 801 and radiopower receiver 803. For example, it may be distributed across one or more other satellites (i.e., in orbital computing). In some cases, the processing system 805 may be distributed across orbital computer systems and ground computer systems. Generally, the processing system 805 comprises one or more memory components (e.g., hard drives, solid-state memory, RAM, EPROM, etc.) storing instructions causing the processing system to implement the processing steps of the method disclosed herein, and one or more processor components configured to perform the processing steps. Preferably, the processing system 805 also comprises, or communicates with, transmitters and / or receivers to communicate with other parts of system 800 as needed.

[0104] The above disclosure is intended to be illustrative in nature and to illustrate only the invention described in the claims. Various modifications to the embodiments described above will be obvious to those skilled in the art. For example, it will be understood that, generally, parameter testing may be repeated as necessary to increase the reliability of the results because transmission was interrupted. It will also be understood that a test radio power transmission may not consist of a single continuous transmission, but rather a series of separate transmissions that may be distributed over a substantially longer period than the actual time the power is being transmitted. Furthermore, different test transmissions may have different durations depending on the parameter being tested, the amount of data required to have a given level of confidence in the results, and so on.

[0105] The method described above may, in some implementations, only need to be performed once between any two radiopower transmitters and receivers. However, in practice, the preferred radiopower transmission mode may need to be re-determined at intervals. In the case of satellites, this may be during each pass (or multiple times within a single pass) between the radiopower transmitter and receiver to account for changing factors such as the orientation of the radiopower transmitter and receiver that may affect the preferred radiopower transmission mode. However, it may be preferable to re-determine the preferred radiopower transmission mode at one or more intervals, regardless of whether the radiopower transmitter and receiver are moving relative to each other. This can take into account how the preferred radiopower transmission mode may vary with different amounts of energy to be transmitted radioly, in order to account for environmental factors such as weather, or simply to account for the natural degradation of the radiopower transmitter and / or radiopower receiver over their lifetimes.

[0106] Specific aspects of the present invention are described in the following numbered clauses. 1. A method for determining a preferred wireless power transmission mode, comprising receiving an indicator of power received by a wireless power receiver for each of a plurality of test wireless power transmissions received by a wireless power receiver, wherein at least two of the wireless power transmissions correspond to different wireless power transmission modes. A method comprising determining a preferred radio power transmission mode based on an indicator of power received by a radio power receiver for at least one of the test radio power transmissions. 2. The method according to Clause 1, wherein each radio power transmission mode defines a combination of at least two laser pulses, and each of the at least two laser pulses has at least a different wavelength, a different instantaneous or average power, or a different pulse mode from each of the other at least two laser pulses. 3. Each of the multiple test wireless power transmissions is sequentially received by the wireless power receiver. The method according to clause 1 or 2, further comprising determining, between each test radio power transmission, the radio power transmission mode to be used for the next test radio power transmission. 4. The method according to Clause 3, wherein the determination of the radio power transmission mode to be used for the next test radio power transmission is based on a previously received index of the power received by the radio power receiver and at least one of the radio power transmission modes used in a previous test radio power transmission. 5. The method according to Clause 3 or 4, wherein a genetic algorithm and / or machine learning is used to determine the radio power transmission mode to be used for the next test radio power transmission. 6. The method of any one of clauses 3 to 5, wherein if the power received from the latest test radio power transmission is less than or equal to a certain threshold of power received from test radio power transmissions preceding the latest test radio power transmission, no further radio power transmission mode is determined. 7. The method described in any one of the preceding clauses, wherein the number of test radio power transmissions in multiple test radio power transmissions does not exceed a specified number. 8. Multiple test radio power transmissions include one or more initial test radio power transmissions. The method described in any one of the preceding clauses, wherein each of the initial one or more test radio power transmissions corresponds to a predetermined radio power transmission mode. 9. The method is configured to be used in conjunction with a wireless power receiver equipped with a solar cell, The method according to any one of the preceding clauses, wherein each wireless power transmission mode includes a number of different wavelengths equal to at least the number of junctions of the solar cell. 10. The method according to Clause 9, wherein the wavelength is based on the band gap of the solar cell junction. 11. The method of any one of the preceding clauses, wherein for each test radiopower transmission, determining a preferred radiopower transmission mode based on an indicator of power received by a radiopower receiver includes selecting the radiopower transmission mode corresponding to one of the test radiopower transmissions as the preferred radiopower transmission mode. 12. For each test wireless power transmission, a preferred wireless power transmission mode may be determined based on the power indicator received by the wireless power receiver. For each test wireless power transmission, the external quantum efficiency spectral response curve is estimated based on the power indicator received by the wireless power receiver, and The method according to any one of the clauses 2 to 11, comprising determining a preferred wireless power transmission mode based on an external quantum efficiency spectral response curve. 13. The method according to clause 12, wherein a preferred wireless power transmission mode is further determined based on a laser available to the wireless power transmitter. 14. The method described in any one of the preceding clauses, wherein the preferred wireless power transmission mode is determined using artificial intelligence such as a neural network. 15. The method according to Clause 14, wherein artificial intelligence is trained with training data derived from a previous implementation of the method. 16. The method according to any one of the preceding clauses, wherein the preferred radio power transmission mode is a radio power transmission mode that enables a radio power receiver to receive maximum power or a specified amount of power. 17. The method according to any one of the clauses 1 to 15, wherein the preferred radio power transmission mode is a radio power transmission mode that enables the most efficient radio transfer of power from the radio power transmitter to the radio power receiver. 18. The method according to any one of the clauses 1 to 17, wherein the preferred radio power transmission mode is a radio power transmission mode that enables radio power transfer to the radio power receiver without increasing the temperature of the radio power receiver and / or radio power transmitter beyond a threshold amount. 19. The method according to any one of the clauses 1 to 18, wherein the preferred radio power transmission mode is a radio power transmission mode that minimizes degradation of the radio power receiver and / or radio power transmitter. 20. The method of any one of the preceding clauses, further comprising transmitting a test radio power transmission to a radio power receiver for each of a plurality of test radio power transmissions. 21. The method of any one of the preceding clauses, further comprising wirelessly transmitting power from a wireless power transmitter to a wireless power receiver in accordance with a preferred wireless power transmission mode. 22. The method described in any one of the preceding clauses, wherein one or both of the radiopower transmitter and the radiopower receiver are space objects, and optionally a satellite. 23. A computer program configured, when executed, to cause a computing system to perform an action described in any of the preceding clauses. 24. Non-temporary memory storing computer programs as described in Clause 23. 25. A satellite configured to perform the method described in any one of the clauses 1 to 22.

Claims

1. A method for determining a preferred wireless laser power transmission mode, The method involves receiving an indicator of power received by a wireless power receiver for each of a plurality of test wireless laser power transmissions received by the wireless power receiver, wherein at least two of the test wireless laser power transmissions correspond to different wireless laser power transmission modes. The process includes determining a preferred wireless laser power transmission mode for at least one of the test wireless power transmissions based on the indicator of power received by the wireless power receiver, A method wherein each wireless laser power transmission mode defines a combination of at least two laser pulses, each of which has a different wavelength.

2. Each of the plurality of test wireless laser power transmissions is sequentially received by the wireless power receiver. The method according to claim 1, further comprising determining the wireless laser power transmission mode to be used for the next test wireless laser power transmission between each test wireless laser power transmission.

3. The method according to claim 2, wherein the determination of the wireless laser power transmission mode to be used for the next test wireless laser power transmission is based on at least one of a previously received index of power received by the wireless power receiver and the wireless laser power transmission mode used in a previous test wireless laser power transmission.

4. The method according to claim 2 or 3, wherein a genetic algorithm and / or machine learning is used to determine the wireless laser power transmission mode to be used for the next test wireless laser power transmission.

5. The method according to any one of claims 2 to 4, wherein if the power received from the latest test wireless laser power transmission is less than or within a certain threshold of the power received from a test wireless laser power transmission preceding the latest test wireless laser power transmission, no further wireless laser power transmission mode is determined.

6. The method according to any one of the prior claims, wherein the number of test wireless laser power transmissions in the plurality of test wireless laser power transmissions does not exceed a predetermined number.

7. The plurality of test wireless laser power transmissions include one or more initial test wireless laser power transmissions. The method according to any one of the prior claims, wherein each of the initial one or more test wireless laser power transmissions corresponds to a predetermined wireless laser power transmission mode.

8. The method described above is configured to be used in conjunction with a wireless power receiver equipped with a solar cell, The method according to any one of the prior claims, wherein each wireless laser power transmission mode includes at least a number of different wavelengths equal to the number of junctions of the solar cell.

9. The method according to claim 8, wherein the wavelength is based on the band gap of the junction of the solar cell.

10. The method according to any one of the prior claims, wherein determining a preferred wireless laser power transmission mode for each of the test wireless laser power transmissions, based on the index of power received by the wireless power receiver, includes selecting a wireless laser power transmission mode corresponding to one of the test wireless laser power transmissions as the preferred wireless laser power transmission mode.

11. For each of the test wireless laser power transmissions, a preferred wireless laser power transmission mode is determined based on the power index received by the wireless power receiver. For each of the test wireless laser power transmissions, the external quantum efficiency spectral response curve is estimated based on the indicator of power received by the wireless power receiver. The method according to any one of the prior claims, comprising determining the preferred wireless laser power transmission mode based on the external quantum efficiency spectral response curve.

12. The method according to any one of the prior claims, wherein the preferred wireless laser power transmission mode is determined using artificial intelligence such as a neural network.

13. The method according to claim 12, wherein the artificial intelligence is trained with training data derived from a previous implementation of the method.

14. The method according to any one of the prior claims, wherein the preferred wireless laser power transmission mode is a wireless laser power transmission mode that enables the wireless power receiver to receive maximum power.

15. The method according to any one of claims 1 to 15, wherein the preferred wireless laser power transmission mode is a wireless laser power transmission mode that enables the wireless power receiver to receive a specified amount of power.

16. The method according to any one of claims 1 to 13, wherein the preferred wireless laser power transmission mode is a wireless laser power transmission mode that enables the most efficient wireless transfer of power from the wireless power transmitter to the wireless power receiver.

17. The method according to any one of claims 1 to 16, wherein the preferred wireless laser power transmission mode is a wireless laser power transmission mode that enables wireless power transfer to the wireless power receiver without increasing the temperature of the wireless power receiver and / or the wireless power transmitter beyond a threshold amount.

18. The method according to any one of claims 1 to 17, wherein the preferred wireless laser power transmission mode is a wireless laser power transmission mode that minimizes the degradation of the wireless power receiver and / or the wireless power transmitter.

19. The method according to any one of the prior claims, further comprising transmitting the test wireless laser power transmission to the wireless power receiver for each of the plurality of test wireless laser power transmissions.

20. The method according to any one of the prior claims, further comprising wirelessly transmitting power from the wireless power transmitter to the wireless power receiver in accordance with the preferred wireless laser power transmission mode.

21. The method according to any one of the prior claims, wherein one or both of the wireless power transmitter and the wireless power receiver are space objects.

22. The method according to claim 21, wherein the space object is a satellite.

23. A computer program configured, when executed, to cause a computing system to perform the method described in any one of the prior claims.

24. Non-temporary memory storing the computer program described in claim 23.

25. A satellite configured to perform the method described in any one of claims 1 to 22.

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