JPWO2018016620A1 - Vibration power generator - Google Patents

Abstract

The negative impedance conversion circuit (26) applies vibration to the non-linear oscillator (50). The switch switching unit (24) is configured such that the negative impedance conversion circuit (26) is not connected to the non-linear oscillator (50) when the amplitude of the vibration of the non-linear oscillator (50) is equal to or greater than a preset threshold. In the second state, when the amplitude of the vibration of the non-linear oscillator (50) is less than the threshold, the negative impedance conversion circuit (26) is connected to the non-linear oscillator (50) to excite the non-linear oscillator (50) Make it The amplitude / frequency detection unit (41) detects the vibration frequency of the non-linear oscillator (50). The threshold setting unit (4212) sets the threshold according to whether or not the vibration frequency is included in the frequency band in which the excitation unit including the multiple operating point coexistence band of the non-linear vibrator (50) excites.

Description

  The present invention relates to a vibration power generator.

  In recent years, the attention of energy harvesting (environmental power generation) has been increasing. Energy used for environmental power generation is light with low density such as light such as sunlight and illumination light, vibration emitted from machinery and structures, heat and so on, and this energy that is usually thrown away is efficiently converted into power and utilized It is

  A resonant vibration power generator for converting vibration energy into electric power is configured by incorporating a vibrator comprising an mass element and a spring element and an electromechanical transducer. A vibration power generator is mechanically coupled to a vibration source such as a vibrating machine, and the vibrator is mechanically resonated by the vibration of the vibration source to convert a portion of the vibration energy of the vibration source into electrical energy with an electromechanical converter. Do.

  As such a vibration power generation apparatus, one using an electromagnetic converter, one using a piezoelectric element, one using a magnetostrictive element, etc. is devised as an electromechanical transducer, and the vibrator is a leaf spring. , And a linear vibrator using a coil spring, a pendulum or the like as a spring element have been proposed (see, for example, Non-Patent Document 1 and Non-Patent Document 2). Alternatively, a vibration power generation apparatus using a magnetic spring using a suction force or a repulsion force by a permanent magnet as a restoring force has also been proposed (see, for example, Patent Document 1 and Patent Document 2).

  These vibration power generators include so-called electromechanical transducers that convert mechanical energy of the vibrator into electrical energy, and the vibrator is configured to resonate by matching the vibration frequency of the vibration source with the natural vibration frequency of the vibrator. The vibration amplitude of is increased. The electromechanical converter produces larger generated power as the vibration amplitude of the vibrator is larger. In order to increase the vibration amplitude at the resonant frequency of the vibrator, it is preferable to design the vibrator so as to lower the mechanical loss of the vibrator, that is, to increase the mechanical Q value of the vibrator. However, as the mechanical Q value of the vibrator increases, the effective operating band is correspondingly reduced, and the power generation performance drops significantly when the vibration frequency of the vibration source and the natural vibration frequency of the vibrator deviate from each other. . In particular, in many of the actual vibration sources, the vibration frequency fluctuates with time. Therefore, there is a limit in designing a large mechanical Q value of the vibrator in the vibration power generator.

  Further, a vibration power generation apparatus provided with a control circuit that changes the operation of the vibrator in accordance with the amplitude fluctuation of the vibration source has been proposed (see, for example, Patent Document 3). This vibration power generator includes an electromagnetic type electromechanical transducer, and adjusts the characteristics of the electromechanical transducer according to the amplitude fluctuation of the vibration source. However, in this vibration power generation device, the generated power is reduced when the vibration frequency of the vibration source fluctuates.

  Furthermore, a variable capacity vibration power generator has been proposed that includes a plurality of vibrators and switches to a vibrator that is optimal for fluctuations in the vibration frequency of the vibration source (see Patent Document 4). However, the vibration power generation device described in Patent Document 4 may not be sufficiently optimized when the vibration frequency of the vibration source fluctuates continuously. Further, there has been proposed a method of realizing a state in which a vibrator resonates in response to an arbitrary vibration source by actively controlling the operation of the vibrator (see Patent Document 5). However, the technology described in Patent Document 5 requires a sensor for measuring the velocity of the vibration source, which may make the configuration complicated.

  On the other hand, a resonance type vibration power generator is proposed which includes a non-linear oscillator having a mass element and a non-linear spring element, and an electromechanical transducer for converting mechanical energy generated by the non-linear oscillator into electrical energy. (See, for example, Patent Document 6). This vibration power generator makes it possible to widen the effective operating band while increasing the mechanical Q factor by using a non-linear spring element. However, in the resonant frequency band, the non-linear oscillator can have both the large amplitude oscillation operating point and the small amplitude oscillation operating point. Therefore, in this vibration power generation apparatus, the amplitude threshold of the non-linear vibrator is set in advance, and when the vibration amplitude of the non-linear vibrator is less than the amplitude threshold, the impedance on the output side viewed from the electromechanical transducer is made negative. Energy is circulated to the non-linear oscillator side via a mechanical converter. As a result, the power generation efficiency is enhanced by exciting the non-linear oscillator to forcibly change the operating point to the large amplitude oscillating operating point.

JP 2002-281727 A JP 2005-33917 A Unexamined-Japanese-Patent No. 2003-199313 Japanese Patent Application Laid-Open No. 2005-137071 JP, 2009-17769, A JP 2012-60864 A

S. P. Beeby, M. J. Tudor, N. M. White, Energy Harvesting Vibration Sources for Microsystems Applications, Meas. Sci. Technol., Vol. 17 (2006) pp. R175-R195. P. D. Mitcheson, E. M. Yeatman, G. K. Rao, A. S. Holmes, T. C. Green, Energy Harvesting from Human and Machine Motion for Wireless Electronic Devices, Proc. Of the IEEE, Vol. 96, No. 9 (2008) pp. 1457-1486.

  However, in the vibration power generation device described in Patent Document 6, the vibration amplitude threshold is constant regardless of the amplitude or frequency of the vibration source. Therefore, even when the vibration frequency of the vibration source is not included in the multiple operating point coexisting band of the non-linear vibrator, the non-linear vibrator is excited because the vibration amplitude of the non-linear vibrator is equal to or less than the amplitude threshold. In this case, the vibration power generation apparatus continues to circulate energy to the non-linear vibrator side, which causes a problem that energy is wasted. Furthermore, even when the vibration frequency of the vibration source is included in the multiple operating point coexisting band of the non-linear vibrator, if the setting of the threshold is inappropriate, a case where an approximate periodic solution not synchronized with the vibration source may be generated In this case as well, the vibration power generation apparatus continues to circulate energy to the non-linear oscillator side, and there is a problem that energy is wasted wastefully.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration power generation device in which wasteful energy consumption is suppressed.

In order to achieve the above object, a vibration power generation device according to the present invention is
A non-linear oscillator having a mass element and a non-linear spring element;
An electromechanical transducer for converting mechanical energy given from the vibration source to the non-linear oscillator into electrical energy;
An output circuit for outputting the electrical energy input from the electromechanical converter to the outside;
An excitation unit that vibrates the non-linear element;
When the amplitude of the vibration of the non-linear vibrator is equal to or greater than a preset threshold value, the excitation unit is set to the first state in which the non-linear vibrator is not connected, and the vibration amplitude of the non-linear vibrator is less than the threshold A state switching unit configured to connect the excitation unit to the non-linear oscillator and bring the non-linear oscillator into a second state for excitation;
A frequency detection unit that detects the vibration frequency of the vibration source;
A threshold setting unit configured to set the threshold according to whether or not the vibration frequency is included in a frequency band in which an excitation unit including a plurality of operating point coexistence bands in which the non-linear oscillator can take a plurality of operating points excites; And.

  According to the present invention, when the state switching unit is in the first state in which the exciting unit is not connected to the non-linear vibrator when the amplitude of the non-linear vibrator is equal to or greater than the preset threshold, the amplitude of the vibration of the non-linear vibrator is If it is less than the threshold value, the excitation unit is connected to the non-linear oscillator to bring the non-linear oscillator into the second state for excitation. Then, the threshold setting unit sets the threshold according to whether or not the vibration frequency is included in the frequency band in which the excitation unit including the multiple operating point coexistence band in which the non-linear oscillator can take multiple operating points is excited. . Thus, for example, if the threshold setting unit sets the threshold level to zero when the vibration frequency of the non-linear oscillator is not included in the plurality of operating point coexistence bands, the vibration frequency of the non-linear oscillator coexists with the plurality of operation points If it is not included in the frequency band installed corresponding to the band, the excitation unit is not connected to the non-linear oscillator (that is, the non-linear oscillator is in a power generation state and is not excited). Therefore, when the vibration frequency of the non-linear oscillator is not included in the frequency band excited by the excitation unit including the multiple operating point coexistence band, it is possible to prevent energy from being returned from the output circuit to the non-linear oscillator wastefully. Energy consumption is reduced. Further, for example, when the vibration frequency of the non-linear vibrator is included in the frequency band in which the excitation unit excites, the threshold setting unit sets the threshold to an appropriate value previously determined according to the amplitude and frequency of the vibration source. As a result, the occurrence of the approximately periodic solution can be suppressed, energy can be prevented from being unnecessarily returned from the output circuit to the non-linear oscillator, and unnecessary energy consumption can be suppressed.

It is a block diagram of the vibration electric power generating apparatus which concerns on embodiment of this invention. It is a figure showing the nonlinear spring characteristic of the nonlinear oscillator concerning an embodiment. It is a figure which shows the frequency characteristic of the nonlinear oscillator which concerns on embodiment, and a linear oscillator. It is a block diagram showing a control part concerning an embodiment. It is a figure which shows the vibration frequency dependence of the vibration amplitude of the nonlinear vibrator concerning embodiment, and an amplitude threshold value. It is a schematic diagram of the vibration electric power generating apparatus which concerns on embodiment. It is a flowchart which shows the voltage threshold value control processing which the control part which concerns on embodiment performs. It is a figure which shows the vibration frequency dependence of the vibration electric power generating apparatus which concerns on a comparative example. It is a figure which shows the vibration frequency dependence of the vibration electric power generating apparatus which concerns on embodiment. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which does not have an excitation part, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear oscillator in the case of the vibration electric power generating apparatus which concerns on a comparative example, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which concerns on embodiment, and the log | history of load resistance of a generator. It is a figure which shows the accumulated power generation amount in the generator of a vibration electric power generating apparatus. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which does not have an excitation part, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear oscillator in the case of the vibration electric power generating apparatus which concerns on a comparative example, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which concerns on embodiment, and the log | history of load resistance of a generator. It is a figure which shows the accumulated power generation amount in the generator of a vibration electric power generating apparatus. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which does not have an excitation part, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear oscillator in the case of the vibration electric power generating apparatus which concerns on a comparative example, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which concerns on embodiment, and the log | history of load resistance of a generator. It is a figure which shows the accumulated power generation amount in the generator of a vibration electric power generating apparatus. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which does not have an excitation part, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear oscillator in the case of the vibration electric power generating apparatus which concerns on a comparative example, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which concerns on embodiment, and the log | history of load resistance of a generator. It is a figure which shows the accumulated power generation amount in the generator of a vibration electric power generating apparatus. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which does not have an excitation part, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear oscillator in the case of the vibration electric power generating apparatus which concerns on a comparative example, and the log | history of load resistance of a generator. It is a figure which shows the displacement of the nonlinear vibrator | oscillator in the case of the vibration electric power generating apparatus which concerns on embodiment, and the log | history of load resistance of a generator. It is a figure which shows the accumulated power generation amount in the generator of a vibration electric power generating apparatus.

  Hereinafter, a vibration power generator according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the vibration power generation apparatus according to the present embodiment includes an electromagnetic vibration energy converter 10, a charging circuit (output circuit) 18, a storage unit 22, a negative impedance conversion circuit 26, and a switch 38. And a switch switching unit (state switching unit) 24, an amplitude / frequency detection unit (frequency detection unit) 41, an amplitude detection unit 25, and a control unit 42. In FIG. 1, u represents the direction of displacement of the vibration source 100, and x represents the direction of displacement of the movable magnet 14 relative to the vibration source 100. In the electromagnetic vibration energy converter 10, the same pole is opposed between the cylinder 56, the pair of fixed magnets 51 and 52 arranged at both ends in the cylinder axial direction of the cylinder 56, and the fixed magnets 51 and 52. The movable magnet 14 disposed in the cylindrical body 56, the coil 16, and the detection coil 161. The electromagnetic vibrational energy converter 10 is fixed to the vibration source 100. The vibration source 100 may be, for example, a machine, a moving structure, or a human body. The movable magnet 14 corresponds to a mass element displaced in the direction of the arrow AR1 in FIG. A magnetic spring (nonlinear spring element) is formed between the fixed magnets 51 and 52 and the movable magnet 14. Thus, the movable magnet 14 and the fixed magnets 51 and 52 constitute a non-linear vibrator 50 having a mass element and a magnetic spring element. The movable magnet 14 and the coil 16 constitute an electromagnetic induction generator (electromechanical transducer) G that converts mechanical energy given from the vibration source 100 to the non-linear vibrator 50 into electrical energy. The negative impedance conversion circuit 26 and the electromechanical transducer G constitute an excitation unit for exciting the non-linear oscillator 50.

As shown in FIG. 2A, the non-linear oscillator 50 is a movable magnet 14 which is a mass element by a magnetic spring having a so-called hardening characteristic in which the inclination of the restoring force F (x) gradually increases as the absolute value of the displacement x increases. Have a supported configuration. Vibration frequency dependence of the vibration amplitude a ₀ of the nonlinear resonator 50 is shown in the curve S2 in FIG. 2B. Incidentally, FIG. 2B shows the vibration amplitude a ₀ for sinusoidal excitation. The vibration frequency dependency of the vibration amplitude a ₀ of the linear vibrator is maximized at the resonance frequency (ω _E ) and suddenly drops on both sides of the resonance frequency, as shown by the curve S1 in FIG. 2B. In contrast, the vibration frequency dependence of the vibration amplitude a ₀ of the nonlinear resonator 50, the resonance peak is indicated by the curve S2 as bent to the high frequency side. The bending of the resonance peak, the vibration amplitude a ₀ is defined amplitude (maximum amplitude of 1 / √2 corresponding amplitude) above comprising vibration frequency band (hereinafter, referred to as "resonant frequency band".) BW2 is It becomes wider than the resonance frequency band BW1 of the linear oscillator.

  Further, as shown in FIG. 2B, when the vibration frequency of the non-linear oscillator 50 is included in the frequency band BW3 (hereinafter referred to as "multiple operating point coexistence band"), the non-linear oscillator 50 is relatively stable and large. There may be multiple operating points, including an amplitude oscillating operating point (see M1 in FIG. 2B) and a small amplitude oscillating operating point (see M2 in FIG. 2B). When the vibration frequency of the non-linear oscillator 50 is included in the multiple operating point coexistence band BW3, the non-linear oscillator 50 is either the large amplitude oscillation operating point or the small amplitude oscillation operating point according to the initial condition of the oscillation of the oscillation source 100. Converge on heels. In addition, it is known that a so-called jump phenomenon in which the operation point of the non-linear oscillator 50 can be shifted between a large amplitude vibration operation point and a small amplitude vibration operation point occurs depending on the vibration state of the vibration source 100. When the operating point of the non-linear oscillator 50 is stabilized at the small amplitude oscillating operating point, the power generation capacity of the oscillating power generator is significantly reduced. Therefore, in the vibration power generation apparatus according to the present embodiment, the operating point of the non-linear vibrator 50 is stabilized at the large amplitude vibration operating point using the negative impedance conversion circuit 26 (excitation unit). Details will be described later.

  Returning to FIG. 1, the charging circuit 18 outputs the electrical energy input from the generator G to the storage unit 22. The charging circuit 18 includes a rectifier circuit BR18, a smoothing capacitor C18, and a voltage conversion circuit 181. The rectifier circuit BR18 is composed of a diode bridge, and its input end is connected between the two output ends of the coil 16. The capacitor C18 is connected between the output ends of the rectifier circuit BR18. Voltage conversion circuit 181 includes a DC-DC converter and a power factor correction circuit, and boosts or lowers a DC voltage generated between both ends of capacitor C18 and outputs it to storage unit 22. The charging circuit 18 and the storage unit 22 can be regarded as a load R 18 connected to the generator G.

  Power storage unit 22 is formed of a secondary battery, and is charged by charging circuit 18. In addition, the storage unit 22 is connected to the negative impedance conversion circuit 26 and supplies power to the negative impedance conversion circuit 26 in a state where the negative impedance circuit 26 is connected to the generator G.

  The negative impedance conversion circuit 26 includes an operational amplifier OP26 and resistors R261, R262, and R263. The positive input terminal of the operational amplifier OP26 is connected to one end of the coil 16 via the switch 38, and the negative input terminal is connected to the other end of the coil 16 via the resistor R263. The output terminal of the operational amplifier OP26 is connected to the positive input terminal via the resistor R261, and is connected to the negative input terminal via the resistor R262. Furthermore, the operational amplifier OP26 is connected to the storage unit 22 and receives supply of drive power from the storage unit 22. The negative resistance value of the negative impedance conversion circuit 26 is set such that the impedance on the output side viewed from the generator G has a negative value when the switch 38 is in the closed state. That is, in the state of being connected to the generator G, the negative impedance conversion circuit 26 makes the impedance on the output side seen from the generator G negative.

  The switch 38 is composed of a semiconductor element such as an n-type transistor or an FET, or a switching element such as a reed relay, and is opened and closed by the switch switching unit 24.

  From the above description, the output voltage of the detection coil 161 is proportional to the vibration amplitude of the movable magnet 14. When the amplitude value of the output voltage of the detection coil 161 is equal to or greater than a preset voltage threshold (DC, which corresponds to a vibration threshold), the switch switching unit 24 opens the switch 38 to set the negative impedance conversion circuit. 26 is in a state where it is not connected to the generator G (first state, only in the power generation state and in the state where there is no excitation state). On the other hand, when the amplitude value of the output voltage of the detection coil 161 is less than the voltage threshold, the switch switching unit 24 closes the switch 38 to connect the negative impedance conversion circuit 26 to the generator G (second State, at least the excitation state exists). The switch switching unit 24 includes a comparator 241 and a drive circuit 242. The positive input terminal of the comparator 241 is connected to the control unit 42, and the negative input terminal of the comparator 241 is connected to the high potential output terminal of the rectifier circuit BR18. A voltage corresponding to the voltage threshold is input from the control unit 42 to the positive input terminal of the comparator 241. To the negative input terminal of the comparator 241, a voltage having a magnitude corresponding to the amplitude value of the output voltage of the detection coil 161 is input. The comparator 241 outputs an enable signal to the drive circuit 242 when the voltage value at the negative input terminal is less than the voltage threshold at the positive input terminal. On the other hand, the comparator 241 outputs the disable signal to the drive circuit 242 when the voltage value at the negative input terminal is equal to or higher than the voltage threshold at the positive input terminal. The drive circuit 242 outputs a voltage higher than the turn-on voltage of the switch 38 to the switch 38 when the enable signal is input from the comparator 241, and turns on the switch 38 when the disable signal is input from the comparator 241. A voltage lower than the voltage is output to the switch 38.

  The amplitude / frequency detection unit 41 detects the vibration amplitude and frequency of the vibration source 100 from the acceleration waveform acquired by the acceleration sensor 41 a attached to the vibration source 100. The amplitude / frequency detection unit 41 outputs a frequency signal indicating the vibration frequency of the vibration source 100 to the control unit 42.

  The amplitude detection unit 25 detects the amplitude value of the output voltage of the detection coil 161.

  As shown in FIG. 3, the control unit 42 includes a central processing unit (CPU) 421, a main storage unit 422, an auxiliary storage unit 423, a first interface 424, a second interface 425, and a DA converter (hereinafter referred to as (Referred to as “DAC”.) 426 and a bus 427 connecting the components. The main storage unit 422 includes volatile memory and is used as a work area of the CPU 421. The auxiliary storage unit 423 is configured of a non-volatile memory, and stores a program of voltage threshold control processing described later that is executed by the CPU 421. The first interface 424 is connected to the amplitude / frequency detection unit 41, and converts the frequency signal input from the amplitude / frequency detection unit 41 into frequency information indicating the value of the frequency. The second interface 425 outputs voltage value information indicating a voltage value input via the CPU 421 or the bus 427 to the DAC 426. The DAC 426 converts the voltage value information input from the second interface 425 into a voltage signal having a voltage value indicated by the voltage value information, and outputs the voltage signal to the switch switching unit 24.

  In addition, the CPU 421 functions as a frequency acquisition unit 4211 and a threshold setting unit 4212 by reading out a program of voltage threshold control processing stored in the auxiliary storage unit 423 to the main storage unit 422 and executing the program. The auxiliary storage unit 423 also has a correlation table (correlation information storage unit) 4231 that stores correlation information indicating the correlation between the vibration amplitude and frequency of the non-linear vibrator 50 and the voltage threshold value corresponding to the vibration amplitude and frequency. .

  The voltage threshold value indicated by the correlation information is 0 V (first voltage value) in a frequency band other than the frequency band set corresponding to the multiple operating point coexistence band of the nonlinear oscillator 50, and corresponds to the multiple operating point coexistence band The voltage value (second voltage value) is larger than 0 V in the frequency band installed. In addition, the voltage threshold in the multiple operation point coexistence band BW3 is larger than the amplitude value of the output voltage of the detection coil 161 when the nonlinear oscillator 50 vibrates at the small amplitude oscillation operation point in the multiple operation point coexistence band The voltage value is set to a voltage value corresponding to the amplitude value of the output voltage of the detection coil 161 in the case of vibrating with an amplitude smaller than the vibration amplitude of the operating point. For example, it is effective to set to about 90 to 95% of the output voltage amplitude of the detection coil 161 when vibrating at the large amplitude vibration operating point.

Further, the correlation information is appropriately set according to the vibration frequency dependency of the vibration amplitude of the non-linear vibrator 50 and the amplitude of the vibration source. If the vibration frequency dependency of the vibration amplitude of the non-linear vibrator 50 differs depending on the amplitude of the vibration source as shown by the curves S21, S22, S23 in FIG. 4, the multiple operating point coexistence bands BW31, BW32 accordingly , BW33 also different. In this case, the correlation information is the frequency dependency of the voltage threshold reflecting the oscillation frequency dependency of the amplitude threshold as shown by the curves _ath 21 (ω), a _th 22 (ω), and a _th 23 (ω) in FIG. It is set to represent gender. That is, the voltage threshold is 0 V in the frequency bands other than the multiple operating point coexistence bands BW31, BW32, and BW33. The voltage threshold is larger than the amplitude value of the output voltage of detection coil 161 when vibrating at the small amplitude vibration operating point in the multiple operating point coexistence bands BW31, BW32, BW33, and is larger than the vibration amplitude of the large amplitude vibration operating point Is also set to a voltage value corresponding to the amplitude value of the output voltage of the detection coil 161 when vibrating with a small amplitude. For example, it is effective to set to about 90 to 95% of the output voltage amplitude of the detection coil 161 when vibrating at the large amplitude vibration operating point. The correlation information is determined from the vibration frequency characteristic of the non-linear vibrator 50 which is measured from the vibration state of the vibration source 100 measured and measured from the vibration state of the vibration source 100.

  The frequency acquisition unit 4211 acquires, from the first interface 424, frequency information indicating the vibration frequency of the non-linear vibrator 50 detected by the amplitude / frequency detection unit 41.

  The threshold setting unit 4212 sets the voltage threshold depending on whether the vibration frequency of the non-linear oscillator 50 is included in the frequency band set corresponding to the multiple operating point coexistence band. The threshold setting unit 4212 sets the voltage threshold to a voltage value corresponding to the vibration frequency of the non-linear vibrator 50 with reference to the correlation information in the correlation table 4231. Thus, the threshold setting unit 4212 sets the voltage threshold to 0 V (first voltage value) when the vibration frequency of the non-linear vibrator 50 is included in a frequency band other than the multiple operating point coexistence band BW3. When the vibration frequency is included in the multiple operation point coexistence band BW3, the threshold setting unit 4212 sets the voltage threshold to a voltage value (second voltage value) larger than 0V. As described above, this voltage value is the amplitude of the output voltage of the detection coil 161 when the nonlinear oscillator 50 oscillates with an amplitude larger than the amplitude when oscillating in the small amplitude oscillation operating point in the multiple operating point coexisting band BW3. It is a voltage value corresponding to the value.

  Next, the basic operation of the vibration power generator according to the present embodiment will be described. As shown in FIG. 5, in the vibration power generating apparatus, it is assumed that a non-linear spring element SP, a mechanical damping element C and a generator G are connected in parallel between the movable magnet 14 as a mass element and the vibration source 100. Can be represented. In FIG. 5, u represents the direction of displacement of the vibration source 100, and x represents the direction of displacement of the movable magnet 14 as a mass element relative to the vibration source 100. The non-linear spring element SP corresponds to a magnetic spring formed between the fixed magnets 51 and 52 and the movable magnet 14. A non-linear oscillator 50 is composed of the non-linear spring element SP and the mechanical damping element C. Further, switch 38 switches the generator G to one of a state connected to load R 18 configured of charging circuit 18 and storage unit 22 and a state connected to load impedance conversion circuit 26. It can be expressed as

  Then, when the vibration source 100 vibrates in the u direction, the vibration is transmitted to the non-linear vibrator 50, and the movable magnet 14 as a mass element vibrates so as to be displaced relative to the vibration source 100 in the x direction. At this time, a part of mechanical energy generated by the vibration of the movable magnet 14 is converted by the generator G into electric energy. The value of the generated power of the generator G is proportional to the square of the vibration amplitude of the movable magnet 14. When the vibration amplitude of the movable magnet 14 increases, the amplitude value of the output voltage of the generator G increases accordingly.

  The switch switching unit 24 switches the switch 38 in accordance with the magnitude relationship between the amplitude value of the output voltage of the detection coil 161 and the voltage threshold value input from the control unit 42. When the amplitude value of the output voltage of the detection coil 161 is equal to or greater than the voltage threshold, the switch switching unit 24 connects the switch 38 to the load R 18 side. That is, the switch switching unit 24 puts the negative impedance conversion circuit 26 in a non-connection state with the generator G (first state, power generation state only). Thereby, charging circuit 18 configuring load R18 receives power supply from generator G to charge power storage unit 22.

  On the other hand, when the amplitude average value of the output voltage of the detection coil 161 is less than the voltage threshold, the switch switching unit 24 is in a state where the negative impedance conversion circuit 26 is connected to the generator G (second state, excitation state at least Exist). Thereby, energy is circulated from the storage unit 22 to the non-linear vibrator 50 via the generator G, and the non-linear vibrator 50 is excited. The energy for excitation of the non-linear vibrator 50 is to use a part of the energy stored in the storage unit 22 and a part of the energy generated by the power generation by the generator G is consumed. It will be. However, after the non-linear vibrator 50 shifts to the large amplitude vibration operation point due to the excitation, the generated power of the generator G significantly increases. Further, as described later, the voltage threshold is set to 0 V when the vibration frequency of the non-linear vibrator 50 is included in a frequency band other than the multiple operating point coexistence band BW3. Therefore, the consumption of energy stored in storage unit 22 due to excitation is very small.

  Thus, when the amplitude value of the output voltage of the detection coil 161 is equal to or greater than the voltage threshold, the vibration power generation device charges the power storage unit 22 and the amplitude value of the output voltage of the detection coil 161 becomes less than the voltage threshold. It operates to excite the nonlinear oscillator 50. Then, the vibration power generation apparatus changes the voltage threshold according to the vibration frequency of the non-linear vibrator 50. The means for detecting the vibration amplitude of the non-linear vibrator 50 is not limited to that by the detection coil 161 as described above, and any other means may be used.

  Next, the voltage threshold control process performed by the threshold setting unit 4212 to change the voltage threshold according to the vibration frequency of the non-linear vibrator 50 will be described with reference to FIGS. 5 and 6. The voltage threshold control process is started when the program of the voltage threshold control process is activated.

  First, the frequency acquisition unit 4211 acquires the vibration frequency of the vibration source 100 detected by the amplitude / frequency detection unit 41 (step S101).

  Next, the threshold setting unit 4212 sets a voltage threshold corresponding to the vibration amplitude and frequency of the vibration source based on the correlation table 4231 (step S102). The threshold setting unit 4212 sets the voltage threshold to 0 V based on the correlation table 4231 when the acquired vibration frequency is not included in the multiple operation point coexistence band. As a result, regardless of the magnitude of the amplitude value of the output voltage of the detection coil 161, the negative impedance conversion circuit 26 shown in FIG. That is, regardless of the magnitude of the amplitude value of the output voltage of the detection coil 161, power is supplied from the generator G to the charging circuit 18, and the charging circuit 18 charges the power storage unit 22. On the other hand, when the acquired vibration frequency is included in the multiple operating point coexistence band, the threshold setting unit 4212 sets the voltage threshold to an appropriate voltage value based on the correlation table 4231.

  Subsequently, the threshold setting unit 4212 outputs voltage threshold information indicating the set voltage threshold to the second interface 425 (step S103). The second interface 425 performs protocol conversion on voltage threshold information and outputs the converted information to the DAC 426. The DAC 426 performs digital-to-analog conversion on the voltage threshold information input from the second interface 425 and outputs the converted information to the switch switching unit 24.

  Thereafter, the frequency acquisition unit 4211 determines whether or not an end command instructing to end the voltage threshold control process is input (step S104). The end instruction is stored in the main storage unit 422 by the user performing an operation for ending the voltage threshold control process on an input device (not shown) connected to the control unit 42. Then, when the main storage unit 422 stores the end instruction, the frequency acquisition unit 4211 determines that the end instruction is input. If it is determined by the frequency acquisition unit 4211 that the end instruction has not been input (step S104: No), the process of step S101 is performed again. On the other hand, when it is determined by the frequency acquisition unit 4211 that the end instruction has been input (step S104: Yes), the voltage threshold control process ends.

Next, the vibration frequency characteristics of the non-linear vibrator 50 of the vibration power generation device according to the present embodiment will be described in comparison with the vibration frequency characteristics of the non-linear vibrator of the vibration power generation device according to the comparative example. The configuration of the vibration power generation device according to the comparative example is the same as the configuration shown in FIG. However, the voltage threshold is constant regardless of the vibration frequency of the non-linear vibrator 50. That is, as shown in FIG. 7A, the amplitude threshold a _th (ω) with respect to the vibration amplitude a ₀ of the non-linear vibrator 50 becomes constant regardless of the vibration frequency of the non-linear vibrator 50. Incidentally, in FIG. 7A, the circles indicate the vibration amplitude a ₀ of the nonlinear oscillator 50, a solid line indicates the amplitude threshold corresponding to the voltage threshold. Thus, even when the vibration frequency of the non-linear vibrator 50 is in the frequency band BW4 higher than the multiple operating point coexistence band BW3, the non-linear vibrator 50 is excited. Therefore, as shown in FIG. 7A, the amplitude of the non-linear oscillator 50 is larger than the amplitude of the original non-linear oscillator 50 represented by the curve S2 in the frequency band BW4. In this case, the energy corresponding to the increase in amplitude PL (the portion indicated by cross hatching in FIG. 7A) of the non-linear vibrator 50 due to the excitation is wastefully consumed.

On the other hand, in the vibration power generation device according to the present embodiment, the voltage threshold is 0 V when the vibration frequency of the non-linear vibrator 50 is other than the multiple operating point coexistence band BW3. That is, as shown in FIG. 7B, the amplitude threshold a _th (ω) of the nonlinear oscillator is set to a voltage larger than 0 V only when the vibration frequency ω of the nonlinear oscillator 50 is included in the multiple operating point coexistence band BW3. ing. Incidentally, in FIG. 7B, circles show the vibration amplitude a ₀ of the nonlinear oscillator 50, a solid line indicates the amplitude threshold corresponding to the voltage threshold. Thus, the nonlinear oscillator 50 is excited only when the vibration frequency of the nonlinear oscillator 50 is included in the multiple operating point coexistence band BW3. Therefore, energy is not consumed by exciting the non-linear vibrator 50 in a frequency band other than the multiple operation point coexistence band BW3.

Next, the relationship between the displacement of the non-linear vibrator 50 and the load resistance of the generator G near the vibration frequencies ω _A , ω _B , ω _C , ω _D and ω _E shown in FIGS. 7A and 7B will be described. Here, the vibration power generation device which does not include the excitation unit, the vibration power generation device according to the comparative example described above, and the vibration power generation device according to the present embodiment will be described in comparison with each other. In addition, assuming that the initial condition is common, the behavior in the case where a disturbance is input to the nonlinear oscillator 50 when ωt / (2π) reaches 20 will be described. The load resistance of the generator G is positive when power is supplied from the generator G to the storage unit 22, and is negative when energy circulates from the storage unit 22 to the non-linear vibrator 50.

The load resistance of the displacement and the generator G of the nonlinear oscillator 50 at low vibration frequency omega _A near a plurality operating point coexisting band BW3, indicating a history as shown in FIGS. 8A to 8C. Here, FIG. 8A shows the result in the case of the vibration power generation device according to the present embodiment, and FIG. 8C shows the result in the case of the vibration power generation device according to the present embodiment. is there. As shown in FIGS. 8A and 8C, the load resistance ρ (t) in the vibration power generation device without the excitation unit and the vibration power generation device according to the present embodiment changes at a positive value and is stored in power storage unit 22. There is no loss of energy. On the other hand, as shown to FIG. 8B, in the case of the vibration electric power generating apparatus which concerns on a comparative example, when the displacement amplitude of the nonlinear oscillator 50 falls below a threshold value, in order to excite the nonlinear oscillator 50 The load resistance ρ (t) is negative because the energy is circulated to 50. And as shown in FIG. 9, in the case of the vibration electric power generating apparatus which concerns on a comparative example, the accumulation electric power generation amount in the generator G reduces with progress of time. On the other hand, in the case of the vibration power generation device according to the present embodiment, the accumulated power generation amount of the generator G increases with the passage of time, similarly to the case of the vibration power generation device without the excitation unit. In the case of the vibration power generation device according to the comparative example, the non-linear vibrator 50 is unnecessarily excited to generate a large energy loss and a decrease in the accumulated power generation amount.

The displacement of the non-linear vibrator 50 and the load resistance of the generator G in the vicinity of the low vibration frequency ω _B in the multiple operation point coexisting band BW3 show the history as shown in FIGS. 10A to 10C. Here, FIG. 10A shows the result in the case of the vibration power generation device according to the present embodiment, and FIG. 10C shows the result in the case of the vibration power generation device according to the present embodiment. is there. As shown in FIG. 10A, in the case of the vibration power generation apparatus without the excitation unit, transition to the small amplitude vibration operation is made when disturbance is added during the large amplitude vibration operation. On the other hand, as shown in FIG. 10B and FIG. 10C, in the case of the vibration power generation device according to the comparative example and the vibration power generation device according to the present embodiment, a nonlinear vibrator is added when disturbance is added and transition is made to small amplitude vibration operation. 50 is excited. At this time, the load resistance ρ (t) of the generator G temporarily becomes negative. Thereafter, the non-linear oscillator 50 maintains the amplitude before the disturbance is applied. Then, as shown in FIG. 11, in the case of the vibration power generation apparatus without the excitation unit, the increase rate of the accumulated power generation amount in the generator G decreases with the reduction of the amplitude after the disturbance is added. On the other hand, in the case of the vibration power generation device according to the comparative example and the vibration power generation device according to the embodiment, the accumulated power generation amount after the disturbance is applied is the same increase rate as the accumulated power generation amount before the disturbance is applied. It will increase with the passage of time. However, in the case of the vibration power generation device according to the comparative example, the threshold in the vicinity of the vibration frequency ω _B is higher than that of the vibration power generation device according to the present embodiment, and the transition from small amplitude vibration operation to large amplitude vibration operation Takes time. Then, the energy loss is increased by the lengthened time during which the load resistance ρ (t) of the generator G transitions to a negative value.

The displacement of the non-linear vibrator 50 and the load resistance of the generator G in the vicinity of the vibration frequency ω _C in the multiple operation point coexistence band BW3 show a history as shown in FIGS. 12A to 12C. Here, FIG. 12A shows the result in the case of the vibration power generation device according to the present embodiment, and FIG. 12C shows the result in the case of the vibration power generation device according to the present embodiment. is there. As shown to FIG. 12A, in the case of the vibration electric power generating apparatus which does not have an excitation part, if disturbance is added during large amplitude vibration operation | movement, it will transfer to small amplitude vibration operation | movement. On the other hand, as shown in FIG. 12B and FIG. 12C, in the case of the vibration power generation device according to the comparative example and the vibration power generation device according to the present embodiment, a nonlinear vibrator is added when disturbance is added and transition is made to small amplitude vibration operation. 50 is excited. At this time, the load resistance ρ (t) of the generator G temporarily becomes negative. Thereafter, the non-linear oscillator 50 maintains the amplitude before the disturbance is applied. Then, as shown in FIG. 13, in the case of the vibration power generation apparatus without the excitation unit, the increase rate of the accumulated power generation amount in the generator G decreases with the reduction of the amplitude after the disturbance is added. On the other hand, in the case of the vibration power generation device according to the comparative example and the vibration power generation device according to the embodiment, the accumulated power generation amount after the disturbance is applied is the same increase rate as the accumulated power generation amount before the disturbance is applied. It will increase with the passage of time. However, in the case of the vibration power generation device according to the comparative example, the threshold in the vicinity of the vibration frequency ω _C is lower than that of the vibration power generation device according to the present embodiment, and the transition from small amplitude vibration operation to large amplitude vibration operation Takes time. Then, the energy loss is increased by the lengthened time during which the load resistance ρ (t) of the generator G transitions to a negative value.

The displacement of the non-linear vibrator 50 and the load resistance of the generator G in the vicinity of the high vibration frequency ω _D in the multiple operation point coexisting band BW3 show the history as shown in FIGS. 14A to 14C. Here, FIG. 14A shows the result in the case of the vibration power generation device without the excitation part, FIG. 14B shows the result in the case of the vibration power generation device according to the above comparative example, and FIG. 14C shows the result in the case of the vibration power generation device according to the present embodiment. is there. As shown in FIG. 14A, in the case of the vibration power generation apparatus without the excitation unit, the amplitude can not be converged to the large amplitude operation under the given initial condition and is converged to the small amplitude operation. On the other hand, as shown to FIG. 14B, in the case of the vibration electric power generating apparatus which concerns on a comparative example, whenever the displacement amplitude of the nonlinear oscillator 50 falls below a threshold value, the nonlinear oscillator 50 is excited each time. At this time, the load resistance ρ (t) of the generator G temporarily becomes negative. Further, as shown in FIG. 14C, in the case of the vibration power generation apparatus according to the present embodiment, when a disturbance is applied, the non-linear vibrator 50 is temporarily excited, and then the large amplitude vibration operation is continued. And as shown in FIG. 15, in the case of the vibration electric power generating apparatus which is not provided with the excitation part, after the accumulated electric power generation amount of the generator G rises to about 0.4, it becomes substantially constant. However, in the case of the vibration power generation device according to the comparative example, the threshold in the vicinity of the vibration frequency ω _D is lower than that of the vibration power generation device according to the present embodiment, and the transition from the small amplitude vibration operation to the large amplitude vibration operation As the accumulated power generation amount of the generator G rises to about 0.4, the accumulated power generation amount gradually decreases as the non-linear oscillator 50 is repeatedly excited. On the other hand, in the case of the vibration power generation apparatus according to the present embodiment, after being stabilized by the large amplitude vibration operation, the accumulated power generation amount in the generator G increases with time.

The displacement of the non-linear vibrator 50 and the load resistance of the generator G in the vicinity of the high vibration frequency ω _E outside the multiple operation point coexistence band BW3 show histories as shown in FIGS. 16A to 16C. Here, FIG. 16A shows the result in the case of the vibration power generation device without the excitation part, FIG. 16B shows the result in the case of the vibration power generation device according to the above comparative example, and FIG. is there. Since only a small amplitude operation exists at this vibration frequency, as shown in FIG. 16A, in the case of a vibration power generator without an excitation unit, the response of the non-linear vibrator 50 converges to the small amplitude operation through a transient state. On the other hand, as shown to FIG. 16B, in the case of the vibration electric power generating apparatus which concerns on a comparative example, whenever the displacement amplitude of the nonlinear oscillator 50 falls below a threshold value, the nonlinear oscillator 50 is excited repeatedly each time. At this time, the load resistance ρ (t) of the generator G temporarily becomes negative. Further, as shown in FIG. 16C, in the case of the vibration power generation device according to the present embodiment, the non-linear vibrator 50 is not excited as in the case of the vibration power generation device without the excitation portion, and converges to the small amplitude operation. Then, as shown in FIG. 17, in the case of the vibration power generation device according to the comparative example, after the accumulated power generation amount of the generator G rises to about 0.15, the accumulation is accompanied by the non-linear oscillator 50 being excited repeatedly. The amount of power generation gradually declines. On the other hand, in the case of the vibration power generation device without the excitation unit and the vibration power generation device according to the present embodiment, the increase rate of the accumulated power generation amount in the generator G increases with time while decreasing with time. In the case of the vibration power generation device according to the comparative example, the non-linear vibrator 50 is unnecessarily excited to generate a large energy loss and a decrease in the accumulated power generation amount.

As described above, in the case of the vibration power generation apparatus according to the comparative example, when operating near the vibration frequency ω _A, near ω _{D, and} near ω _E , as shown in FIGS. Recirculation of energy to the vibrator 50 occurs repeatedly, and the accumulated power generation amount of the generator G decreases with time. Further, in the case of the vibration power generation apparatus without the excitation unit, when operating in the vicinity of the vibration frequency ω _{B, in the} vicinity of ω _{C and in the} vicinity of ω _D , as shown in FIG. 11, FIG. 13 and FIG. The amplitude decreases, and the rate of increase in the accumulated power generation amount of the generator G is significantly reduced. In contrast, in the case of the vibration generator according to the present embodiment, the vibration frequency omega _A near omega _B vicinity, omega _C near, omega _D neighborhood, all neighboring omega _E, the accumulated power generation amount of the generator G is It increases with time. That is, in the vibration power generation device according to the present embodiment, wasteful energy consumption in the generator G is suppressed in a wide vibration frequency band compared to the vibration power generation device without the excitation portion and the vibration power generation device according to the comparative example. And the accumulated power generation amount is large.

  As described above, according to the vibration power generation device according to the present embodiment, when the switch voltage of the detection coil 161 is equal to or higher than the preset threshold value, the negative impedance conversion circuit 26 is a generator. The first state, which is not connected to G, is set. On the other hand, when the output voltage of the detection coil 161 is smaller than the threshold, the switch switching unit 24 brings the negative impedance conversion circuit 26 into the second state in which it is connected to the generator G. Then, depending on whether the vibration frequency detected by the amplitude / frequency detection unit 41 by the threshold setting unit 4212 is included in the multiple operation point coexistence band BW3 in which the non-linear oscillator 50 can take a plurality of operation points. Control the threshold. Thus, for example, if the threshold setting unit 4212 controls the threshold so that the threshold is 0 when the vibration frequency of the non-linear oscillator 50 is not included in the multiple operating point coexistence band BW3, the non-linear oscillator 50 The negative impedance conversion circuit 26 is not connected to the generator G when the vibration frequency of the second operating frequency is not included in the multiple operating point coexistence band BW3. Therefore, in the case where the vibration frequency of the non-linear oscillator 50 is not included in the multiple operating point coexisting band BW3, it is possible to prevent the energy from being returned from the charging circuit 18 to the non-linear oscillator 50 through the generator G. Energy consumption is suppressed.

Further, the vibration power generation apparatus according to the present embodiment includes a correlation table 4231 that stores correlation information indicating the correlation between the vibration frequency of the non-linear vibrator 50 and the voltage threshold value corresponding to the vibration frequency. Thereby, the user can change the oscillation frequency dependency of the voltage threshold only by rewriting the correlation information stored in the correlation table 4231. Therefore, for example, when the vibration frequency dependency of the vibration amplitude a ₀ of the non-linear vibrator 50 changes with the change of the electromagnetic vibration energy converter 10 incorporated into the vibration power generation apparatus, the nonlinearity after changing the vibration frequency dependency of the voltage threshold It can be relatively easily changed to one compatible with the transducer 50.

(Modification)
As described above, in the embodiment of the present invention, the vibration power generation device 1 determines whether the power generation operation and the excitation operation are performed by determining whether the vibration frequency of the non-linear vibrator 50 falls within the multiple operating point coexistence band BW3. . However, the present invention is not limited to the configuration of the above-described embodiment. For example, according to the characteristic change of the non-linear oscillator 50 and the vibration source 100, the frequency band installed corresponding to the multiple operating point coexistence band and the size of the threshold of the vibration amplitude are adaptively changed. Good.

  Specifically, in order to detect the operating state of the non-linear vibrator, the vibration power generation apparatus measures a vibration waveform measurement unit that measures the vibration waveform of the vibration source 100, and a vibrator response that measures the response waveform of the non-linear vibrator 50. A waveform measurement unit and a phase difference detection unit that detects a phase difference between the vibration waveform of the vibration source 100 and the response waveform of the non-linear vibrator 50 are provided. Then, the threshold setting unit causes the phase difference detected by the phase difference detection unit to have a constant value, that is, the response waveform of the non-linear oscillator 50 has the same frequency (synchronizes) with the vibration waveform of the vibration source 100. To control the threshold adaptively. In this case, it is not necessary to determine whether the frequency of the vibration source 100 is in the multiple operating point coexistence band BW3. The phase difference between the vibration waveform of the vibration source 100 and the response waveform of the nonlinear oscillator 50 deviates by about ± 90 ° outside the multiple operating point coexistence band BW3, and the phase difference is ± 90 ° within the multiple operating point coexistence band BW3. Is also a small value. Then, the threshold setting unit adaptively controls the threshold in a region where the phase difference detected by the phase difference detection unit becomes a constant value smaller than ± 90 °. This makes it unnecessary to determine whether the vibration frequency of the vibration source 100 falls within the multiple operating point coexistence band BW3.

  Although in the embodiment, the generator G is a so-called electromagnetic generator composed of the movable magnet 14 and the coil 16, the generator G has been described as long as it converts vibration energy into electric energy. The configuration of is not limited to this. For example, the generator may be configured of a generator using a piezoelectric element.

  In the embodiment, the mode in which power is supplied from the generator G to the charging circuit 18 and the non-linear vibrator 50 are switched by switching between the state where the negative impedance conversion circuit 26 is connected to the generator G and the state where the negative impedance conversion circuit 26 is not connected. An example has been described in which the mode is switched to the mode in which is excited. Not limited to this, for example, the generator and the excitation circuit for exciting the non-linear oscillator 50 may be separately provided, and the excitation circuit and the excitation unit may be operated in the excitation mode.

  Although the threshold setting unit 4212 described the example using the correlation table 4231 in the embodiment, the threshold setting unit 4212 is not limited to the configuration using the correlation table 4231. For example, the threshold setting unit 4212 may be configured to use relational expression information indicating a relational expression between a voltage threshold and a vibration frequency, instead of the correlation table 4231.

  In the embodiment, an example has been described in which the threshold setting unit 4212 sets the voltage threshold to 0 V when the vibration frequency of the non-linear vibrator 50 is included in a frequency band other than the multiple operating point coexistence band BW3. However, the magnitude of the voltage threshold is not limited to 0 V when the vibration frequency of the non-linear vibrator 50 is included in a frequency band other than the multiple operating point coexistence band BW3. The magnitude of the voltage threshold when the vibration frequency of the non-linear vibrator 50 is included in a frequency band other than the multiple operating point coexistence band BW3 is smaller than the vibration amplitude when the non-linear vibrator 50 vibrates at the small amplitude vibration operating point The voltage value may be larger than 0 V as long as the voltage value corresponds to the output voltage of the generator G when vibrating with the vibration amplitude.

  In the embodiment, when the vibration frequency of the non-linear vibrator 50 is included in the multiple operating point coexistence band, an example in which the voltage threshold is a voltage value larger than 0 V has been described. However, the oscillation frequency dependency of the voltage threshold is not limited to this, and for example, the oscillation frequency of the non-linear oscillator 50 is included in a frequency band wider than a plurality of operating point coexisting bands including a plurality of operating point coexisting bands. In this case, the voltage threshold may be a voltage value larger than 0V. In the above description, although the frequency band in which the voltage threshold larger than 0 V is set is made to coincide with the multiple operating point coexistence band of the non-linear oscillator 50, the voltage slightly larger than 0 V The frequency band for which the threshold value is set may be wider, narrower or shifted than the multiple operating point coexistence band of the nonlinear oscillator 50. The power generation efficiency is about 5% or less even if the multiple operating point coexistence band of the nonlinear oscillator 50 and the frequency band where the threshold value is set for the voltage value larger than 0V deviate by about 10% of the band. Fall in the That is, the present invention of setting the threshold in consideration of the multiple operating point coexistence band has a great effect of improving the power generation efficiency as compared with the conventional setting of the threshold.

  As mentioned above, although each embodiment and modification of the present invention (including the thing described in the statement. Hereinafter, the same) were explained, the present invention is not limited to these. The present invention includes those in which the embodiments and the modifications are combined as appropriate, and those in which changes are appropriately applied.

  This application is based on Japanese Patent Application No. 2016-143534 filed on July 21, 2016. The specification, claims, and whole drawings of Japanese Patent Application No. 2016-143534 are incorporated herein by reference.

  The present invention is suitable as a vibration power generator attached to a vibration source such as a machine, a moving structure, or a human body.

10: electromagnetic vibration energy converter, 14: movable magnet, 16: coil, 18: charging circuit, 22: storage unit, 24: switch switching unit, 25: amplitude detection unit, 26: negative impedance conversion circuit, 38: switch , 41: amplitude / frequency detection unit, 41a: acceleration sensor, 42: control unit, 50: non-linear oscillator, 51, 52: fixed magnet, 56: cylinder, 100: vibration source, 161: detection coil, 181: voltage Conversion circuit, 241: comparator, 242: drive circuit, 421: CPU, 422: main storage unit, 423: auxiliary storage unit, 424: first interface, 425: second interface, 426: DAC, 427: bus, 4211 : Frequency acquisition unit, 4212: Threshold setting unit, 4231: Correlation table, BR18: Rectification circuit, C18: Capacitor, G: Generator, OP26: OPEA Flop, R18: load, R261, R262, R263: resistance

Claims (6)

A non-linear oscillator having a mass element and a non-linear spring element;
An electromechanical transducer for converting mechanical energy given from the vibration source to the non-linear oscillator into electrical energy;
An output circuit for outputting the electrical energy input from the electromechanical converter to the outside;
An excitation unit that vibrates the nonlinear oscillator;
When the amplitude of the vibration of the non-linear vibrator is equal to or greater than a preset threshold value, the excitation unit is set to the first state in which the non-linear vibrator is not connected, and the vibration amplitude of the non-linear vibrator is less than the threshold A state switching unit configured to connect the excitation unit to the non-linear oscillator and bring the non-linear oscillator into a second state for excitation;
A frequency detection unit that detects the vibration frequency of the vibration source;
A threshold setting unit configured to set the threshold according to whether or not the vibration frequency is included in a frequency band in which an excitation unit including a plurality of operating point coexistence bands in which the non-linear oscillator can take a plurality of operating points excites; With
Vibration generator. The information processing apparatus further includes a correlation information storage unit that stores correlation information indicating a correlation between the vibration frequency of the non-linear vibrator and a threshold value corresponding to the vibration frequency.
The threshold setting unit sets the threshold to a value according to the vibration frequency with reference to the correlation information.
The vibration power generation device according to claim 1. The threshold is set to be higher than the small amplitude stable point of the multiple operating point coexistence band and lower than the large amplitude stable point.
The vibration power generation device according to claim 1. The threshold setting unit sets the threshold to a first threshold and excites the excitation unit when the vibration frequency is included in a frequency band other than a frequency band in which the excitation unit including the plurality of operating point coexistence bands excites. When the vibration frequency is included in a frequency band, the threshold is set to a second threshold larger than the first threshold.
The vibration power generation device according to any one of claims 1 to 3. The plurality of operating points include a stable small amplitude oscillating operating point and a large amplitude oscillating operating point,
The first threshold is 0,
The second threshold is larger than the vibration amplitude when the nonlinear vibrator vibrates at the small amplitude vibration operating point.
The vibration power generation device according to claim 4. The threshold setting unit adaptively changes a frequency band in which an excitation unit including the plurality of operating point coexistence bands excites and a magnitude of the threshold.
The vibration power generation device according to claim 1.