Inertial measurement units and inertial measurement systems

Abstract

An inertial measurement unit and an inertial measurement system. A device capable of reducing the load on equipment connected to an output destination. The inertial measurement unit includes an inertial sensor, a first signal processing circuit, a second signal processing circuit, a first communication unit and a second communication unit for communicating with an external device, and a mode selection unit for selecting a processing mode from a plurality of modes, including a first processing mode and a second processing mode. The first processing mode is a mode in which, when used as a standalone device, a signal processed by the first signal processing circuit is output from the first communication unit. The second processing mode is a mode in which, when used in a state connected to another inertial measurement unit, the second signal processing circuit performs computational processing on a first signal processed by the first signal processing circuit and a second signal from the other inertial measurement unit input from the second communication unit, and outputs the computationally processed signal from the first communication unit.

Description

Technical Field

[0001] The present invention relates to an inertial measurement device and an inertial measurement system. Background Art

[0002] For example, Patent Document 1 describes a method for processing an acceleration sensor that electrically adds the outputs of multiple MEMS acceleration sensors at the stage of a time-series voltage signal. If the number of MEMS acceleration sensors is N, then by performing the addition process, the noise component is reduced to Therefore, according to this processing method, excellent acceleration detection characteristics can be obtained.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-031032

[0004] However, if the outputs of a plurality of MEMS acceleration sensors are processed by a single computing unit, a large load may be imposed on the computing unit. Summary of the Invention

[0005] The inertial measurement device of the present invention comprises: an inertial sensor; a first signal processing circuit that processes an output signal of the inertial sensor; a second signal processing circuit that processes a signal processed by the first signal processing circuit; a first communication unit and a second communication unit that communicate with an external device; and a mode selection unit that selects a processing mode from a plurality of modes including a first processing mode and a second processing mode, wherein the first processing mode is a mode in which, when used in a single unit, the signal processed by the first signal processing circuit is output from the first communication unit or the second communication unit, and the second processing mode is a mode in which, when used in a state connected to another inertial measurement device, the second signal processing circuit performs computational processing on the first signal processed by the first signal processing circuit and a second signal from the other inertial measurement device input from one of the first communication unit and the second communication unit, and outputs the computationally processed signal from the other of the first communication unit and the second communication unit.

[0006] The inertial measurement system of the present invention has a first inertial measurement unit and a second inertial measurement unit, wherein the first inertial measurement unit and the second inertial measurement unit have: an inertial sensor; a first signal processing circuit that processes an output signal of the inertial sensor; a second signal processing circuit that processes the signal processed by the first signal processing circuit; and a first communication unit and a second communication unit that communicate with an external device. The first inertial measurement unit and the second inertial measurement unit are connected via one of the first communication unit and the second communication unit. The second inertial measurement unit sends the second signal processed by the first signal processing circuit of the second inertial measurement unit to the first inertial measurement unit. The first inertial measurement unit performs computational processing on the first signal processed by the first signal processing circuit of the first inertial measurement unit and the second signal received from the second inertial measurement unit, and outputs the processed signal from the other of the first communication unit and the second communication unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a block diagram showing the inertial measurement unit according to the first embodiment.

[0008] Figure 2 is a block diagram showing an inertial sensor.

[0009] Figure 3 It shows that the application Figure 1 The inertial measurement unit is shown as a block diagram of the inertial measurement system.

[0010] Figure 4 This is a flowchart showing the procedure of the initialization process.

[0011] Figure 5 : is a flowchart showing the procedure of the sampling start process.

[0012] Figure 6 : is a flowchart showing the procedure of the sampling process.

[0013] Figure 7 It shows that the application Figure 1 The inertial measurement unit is shown as a block diagram of the inertial measurement system.

[0014] Figure 8 This is a flowchart showing the procedure of the initialization process.

[0015] Figure 9 : is a flowchart showing the procedure of the sampling start process.

[0016] Figure 10 : is a flowchart showing the procedure of the sampling process.

[0017] Figure 11This is a block diagram showing a conventional inertial measurement system.

[0018] Figure 12 It shows that the application Figure 1 The inertial measurement unit is shown as a block diagram of the inertial measurement system.

[0019] Figure 13 This is a flowchart showing the procedure of the initialization process.

[0020] Figure 14 : is a flowchart showing the procedure of the sampling start process.

[0021] Figure 15 : is a flowchart showing the procedure of the sampling process.

[0022] Description of labels

[0023] 1 Inertial measurement unit; 1A First inertial measurement unit; 1B Second inertial measurement unit; 1C Third inertial measurement unit; 100 Inertial measurement system; 2 Inertial sensor; 21 Three-axis angular velocity sensor; 210 Signal processing circuit; 211x X-axis angular velocity sensor element; 211y Y-axis angular velocity sensor element; 211z Z-axis angular velocity sensor element; 22 Three-axis acceleration sensor; 220 Signal processing circuit; 221x X-axis acceleration sensor element; 221y Y-axis acceleration sensor element; 221z Z-axis acceleration sensor element; 3 1st signal processing circuit; 31 signal processing unit; 32 signal processing unit; 33 signal processing unit; 4 2nd signal processing circuit; 5 host interface; 51 1st communication unit; 52 2nd communication unit; 6 mode selection unit; 7 oscillation circuit; 8 input / output terminal; 9 host device; Ax acceleration; Ay acceleration; Az acceleration; CLK synchronous clock; DAx data; DAx1 data; DAx2 data; DAx3 data; DAy data; DAy1 data; DAy2 data; DAy3 data; DAz data; DAz1 data; DAz2 data; DAz3 data; Dωx data; Dωx1 data; Dωx2 data; Dωx3 data; Dωx3' averaged data; Dωx3a data; Dωx3b data; Dωx3bc added data; Dωx3c data; Dωy data; Dωy1 data; Dωy2 data; Dωy3 data; Dω z data; Dωz1 data; Dωz2 data; Dωz3 data; M1 first processing mode; M2 second processing mode; step S111; step S112; step S121; step S122; step S131; step S132; step S211; step S212; step S213; step S214; step S221; step S222; step S223; step S224; step S231; step S232; S Step 233; Step S234; Step S311; Step S312; Step S313; Step S314; Step S315; Step S316; Step S321; Step S322; Step S323; Step S324; Step S325; Step S326; Step S331; Step S332; Step S333; Step S334; Step S335; Step S336; ωx angular velocity; ωy angular velocity; ωz angular velocity. DETAILED DESCRIPTION

[0024] Hereinafter, an inertial measurement device and an inertial measurement system according to the present invention will be described in detail based on the embodiments shown in the drawings.

[0025] Figure 1 This is a block diagram showing the inertial measurement unit according to the first embodiment. Figure 2 is a block diagram showing an inertial sensor. Figure 3 It shows that the application Figure 1 The inertial measurement unit is shown as a block diagram of the inertial measurement system. Figure 4 This is a flowchart showing the procedure of the initialization process. Figure 5 : is a flowchart showing the procedure of the sampling start process. Figure 6 : is a flowchart showing the procedure of the sampling process. Figure 7 It shows that the application Figure 1 The inertial measurement unit is shown as a block diagram of the inertial measurement system. Figure 8 This is a flowchart showing the procedure of the initialization process. Figure 9 : is a flowchart showing the procedure of the sampling start process. Figure 10 : is a flowchart showing the procedure of the sampling process. Figure 11 is a block diagram showing a conventional inertial measurement system. Figure 12 It shows that the application Figure 1 The inertial measurement unit is shown as a block diagram of the inertial measurement system. Figure 13 This is a flowchart showing the procedure of the initialization process. Figure 14 : is a flowchart showing the procedure of the sampling start process. Figure 15 : is a flowchart showing the procedure of the sampling process.

[0026] Figure 1 The inertial measurement device 1 shown includes an inertial sensor 2, a first signal processing circuit 3 for processing an output signal from the inertial sensor 2, a second signal processing circuit 4 for processing the signal processed by the first signal processing circuit 3, a host interface 5 for communicating with the outside, a mode selection unit 6 for selecting a measurement mode, an oscillation circuit 7 for generating a synchronous clock CLK, and input / output terminals 8 for inputting and outputting the synchronous clock CLK.

[0027] The inertial sensor 2 includes a three-axis angular velocity sensor 21 and a three-axis acceleration sensor 22 .

[0028] The three-axis angular velocity sensor 21 independently detects angular velocity ωx around the X axis, angular velocity ωy around the Y axis, and angular velocity ωz around the Z axis, and outputs digital X-axis angular velocity data Dωx, Y-axis angular velocity data Dωy, and Z-axis angular velocity data Dωz.

[0029] like Figure 2 As shown, such a three-axis angular velocity sensor 21 has an X-axis angular velocity sensor element 211x for detecting the angular velocity ωx around the X-axis, a Y-axis angular velocity sensor element 211y for detecting the angular velocity ωy around the Y-axis, a Z-axis angular velocity sensor element 211z for detecting the angular velocity ωz around the Z-axis, and a signal processing circuit 210 for processing the detection signals from these sensor elements 211x, 211y, 211z and outputting respective data Dωx, Dωy, Dωz.

[0030] Although not shown, the signal processing circuit 210 includes, for example, an analog circuit including an amplifier circuit for amplifying the detection signals from each sensor element 211x, 211y, and 211z, a synchronous detection circuit for synchronously detecting the detection signals, and an A / D conversion circuit for converting the analog signals from the analog circuit into digital signals. The A / D conversion circuit, for example, converts the analog signals of the X-axis angular velocity, the Y-axis angular velocity, and the Z-axis angular velocity into digital data in a time-division manner.

[0031] However, the configuration of the three-axis angular velocity sensor 21 is not particularly limited as long as it has at least one detection axis.

[0032] The three-axis acceleration sensor 22 independently detects acceleration Ax in the X-axis direction, Ay in the Y-axis direction, and Az in the Z-axis direction, and outputs digital X-axis acceleration data DAx, Y-axis acceleration data DAy, and Z-axis acceleration data DAz.

[0033] like Figure 2 As shown, such a three-axis acceleration sensor 22 has an X-axis acceleration sensor element 221x for detecting acceleration Ax in the X-axis direction, a Y-axis acceleration sensor element 221y for detecting acceleration Ay in the Y-axis direction, a Z-axis acceleration sensor element 221z for detecting acceleration Az in the Z-axis direction, and a signal processing circuit 220 for processing detection signals from each of these sensor elements 221x, 221y, 221z and outputting data DAx, DAy, DAz.

[0034] Although not shown, the signal processing circuit 220 includes, for example, an amplifier circuit for amplifying the detection signals from each sensor element 221x, 221y, and 221z, and an A / D converter circuit for converting the analog signals from the amplifier circuit into digital signals. The A / D converter circuit, for example, converts the analog signals of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration into digital data in a time-division manner.

[0035] However, the configuration of the three-axis acceleration sensor 22 is not particularly limited as long as it has at least one detection axis.

[0036] The first signal processing circuit 3 is composed of, for example, a computer and includes a processor (CPU) for processing information, a memory connected to the processor in a communicable manner, and an external interface. Furthermore, the memory stores a program executable by the processor, and the processor reads and executes the program stored in the memory.

[0037] The first signal processing circuit 3 processes the data Dωx, Dωy, Dωz, DAx, DAy, and DAz in a time-division manner.

[0038] Furthermore, the first signal processing circuit 3 includes three signal processing units 31, 32, and 33 that process the data Dωx, Dωy, Dωz, DAx, DAy, and DAz. Signal processing unit 31 is a filter circuit that removes noise from the data Dωx, Dωy, Dωz, DAx, DAy, and DAz and outputs the data Dωx1, Dωy1, Dωz1, DAx1, DAy1, and DAz1, respectively. Furthermore, signal processing unit 32 is a temperature compensation circuit that performs temperature compensation on the data Dωx1, Dωy1, Dωz1, DAx1, DAy1, and DAz1, and outputs the data Dωx2, Dωy2, Dωz2, DAx2, DAy2, and DAz2, respectively. Furthermore, the signal processing unit 33 is a matrix calculation circuit that performs matrix calculations for coordinate transformation on each data item Dωx2, Dωy2, Dωz2, DAx2, DAy2, and DAz2, and outputs each data item Dωx3, Dωy3, Dωz3, DAx3, DAy3, and DAz3. However, the processing content of the first signal processing circuit 3 is not particularly limited.

[0039] The host interface 5 includes a first communication unit 51 and a second communication unit 52. In this embodiment, the first communication unit 51 communicates with the outside world via SPI (Serial Peripheral Interface) communication, and the second communication unit 52 communicates with the outside world via UART (Universal Asynchronous Receiver / Transmitter) communication. However, the communication methods of the first communication unit 51 and the second communication unit 52 are not particularly limited.

[0040] The mode selection unit 6 selects the processing mode of the inertial measurement device 1. In this embodiment, the inertial measurement device 1 has a first processing mode M1 and a second processing mode M2 ​​as processing modes, and the mode selection unit 6 selects a processing mode from these first processing mode M1 and second processing mode M2. Figure 3 As shown, the first processing mode M1 is a mode used when one inertial measurement device 1 is connected to the host device 9. In contrast, as described later, Figure 7 As shown, the second processing mode M2 ​​is used when multiple inertial measurement devices 1 are connected to the host device 9. Furthermore, the second processing mode M2 ​​includes a master mode connected to the host device 9 and a slave mode connected to other inertial measurement devices 1. These modes will be described later.

[0041] The second signal processing circuit 4 is composed of, for example, a computer and includes a processor (CPU) for processing information, a memory connected to the processor in a communicable manner, and an external interface. In addition, the memory stores a program executable by the processor, and the processor reads and executes the program stored in the memory.

[0042] In the second processing mode M2, the second signal processing circuit 4 processes the data Dωx3, Dωy3, Dωz3, DAx3, DAy3, and DAz3 in a time-division manner. The processing contents of the second signal processing circuit 4 will be described later.

[0043] The configuration of the inertial measurement device 1 has been described above. Next, an inertial sampling method using the inertial measurement device 1 will be described.

[0044] There are two inertial sampling methods: a first sampling method performed by connecting a single inertial measurement unit 1 to the host device 9, and a second sampling method performed by connecting multiple inertial measurement units 1 to the host device 9. The sampling methods for each data item Dωx, Dωy, Dωz, DAx, DAy, and DAz performed in a time-division manner are identical. Therefore, for ease of explanation, the sampling method for the data item Dωx will be described as a representative example, and the description of the sampling methods for the other data items Dωy, Dωz, DAx, DAy, and DAz will be omitted.

[0045] <<1st Sampling Method>>

[0046] In the first sampling method, if Figure 3 As shown, an inertial measurement system 100 is constructed in which an inertial measurement device 1 is connected to a host device 9 via a host interface 5. In the illustrated configuration, the inertial measurement device 1 is connected to the host device 9 via a first communication unit 51, but the present invention is not limited thereto and may also be connected to the host device 9 via a second communication unit 52.

[0047] Initialization Processing

[0048] like Figure 4 As shown in the flowchart, first, in step S111, the host device 9 transmits a "first processing mode" command to the inertial measurement unit 1 to notify it to perform sampling in the first processing mode M1. Next, in step S112, the mode selection unit 6 of the inertial measurement unit 1 selects the first processing mode M1 as the processing mode. This completes the initialization process.

[0049] - Sampling processing starts -

[0050] like Figure 5As shown in the flowchart of FIG. 1 , first, as step S121 , the host device 9 sends a “sampling start” command to the inertial measurement device 1 . Next, as step S122 , the inertial measurement device 1 starts sampling the data Dωx. This completes the sampling start process.

[0051] - Sampling Processing -

[0052] like Figure 6 As shown in the flowchart, first, in step S131, the inertial measurement unit 1 samples the data Dωx and transmits the processed data Dωx3 to the host device 9. This processing of the output data Dωx3 corresponds to the processing in the first processing mode M1. Next, in step S132, a determination is made as to whether a "sampling stop" command has been received from the host device 9. If a "sampling stop" command has not been received from the host device 9, the process returns to step S131. If a "sampling stop" command has been received, sampling ends.

[0053] <<Second Sampling Method (Part 1)>>

[0054] In the second sampling method (part 1), if Figure 7 As shown, an inertial measurement system 100 is constructed in which two inertial measurement units 1, namely a first inertial measurement unit 1A and a second inertial measurement unit 1B, are connected in series with a host device 9. Specifically, the first inertial measurement unit 1A is connected to the host device 9 via a first communication unit 51, and the second communication units 52 of the first inertial measurement unit 1A and the second inertial measurement unit 1B are connected to each other.

[0055] Furthermore, input / output terminals 8 of the first inertial measurement unit 1A and the second inertial measurement unit 1B are connected to each other, and the synchronous clock CLK generated by the oscillation circuit 7 of the first inertial measurement unit 1A is input to the second inertial measurement unit 1B. In other words, the first inertial measurement unit 1A and the second inertial measurement unit 1B are synchronized by the synchronous clock CLK generated by the first inertial measurement unit 1A. This allows the first inertial measurement unit 1A and the second inertial measurement unit 1B to sample data Dωx at the same time, eliminating any variation in sampling timing and enabling highly accurate detection of angular velocity ωx.

[0056] Initialization Processing

[0057] like Figure 8As shown in the flowchart, first, in step S211, the host device 9 transmits a "2-unit second processing mode" command to the first inertial measurement unit 1A to notify it to perform sampling in the second processing mode M2 ​​using two inertial measurement units 1. Next, in step S212, the first inertial measurement unit 1A sets itself as the "master" connected to the host device 9 and selects the second processing mode M2 ​​as the processing mode. As a result, the first inertial measurement unit 1A operates in the master mode of the second processing mode M2.

[0058] Next, in step S213, the first inertial measurement unit 1A sends a "2-unit second processing mode" command to the second inertial measurement unit 1B. Next, in step S214, the second inertial measurement unit 1B configures itself as a "slave" connected to the first inertial measurement unit 1A, acting as the master, and selects the second processing mode M2 ​​as the processing mode. The second inertial measurement unit 1B thus operates in slave mode, in the second processing mode M2. This completes the initialization process.

[0059] - Sampling processing starts -

[0060] like Figure 9 As shown in the flowchart, first, in step S221, the host device 9 sends a "sampling start" command to the first inertial measurement unit 1A. Next, in step S222, the first inertial measurement unit 1A starts sampling data Dωx. Next, in step S223, the first inertial measurement unit 1A sends a "sampling start" command to the second inertial measurement unit 1B. Next, in step S224, the second inertial measurement unit 1B starts sampling data Dωx. This completes the sampling start process.

[0061] - Sampling Processing -

[0062] like Figure 10 As shown in the flowchart, first, in step S231, the second inertial measurement unit 1B transmits data Dωx3 (hereinafter referred to as "Dωx3b") obtained by processing the sampled data Dωx as a second signal to the first inertial measurement unit 1A. This process of transmitting data Dωx3b to the first inertial measurement unit 1A, serving as the master, corresponds to the second processing mode M2 / slave mode.

[0063] Next, as step S232, the first inertial measurement device 1A averages the data Dωx3b received as the second signal from the second inertial measurement device 1B and the data Dωx3 (hereinafter referred to as "Dωx3a") generated by itself as the first signal in the second signal processing circuit 4 according to the number of inertial measurement devices 1. Specifically, the second signal processing circuit 4 uses Dωx3a and Dωx3b sampled at the same time to perform an operation of (Dωx3a+Dωx3b) / 2 to calculate the averaged data Dωx3'. In this way, by averaging the two data Dωx3a and Dωx3b, noise can be reduced. In addition, if the number of inertial measurement devices 1 is set to N, the noise component is reduced to 0.01 by performing the addition process.

[0064] Next, in step S233, the first inertial measurement unit 1A transmits the averaged data Dωx3' to the host device 9. This process of calculating and outputting the averaged data Dωx3' corresponds to processing in the second processing mode M2 / master mode. Next, in step S234, the first inertial measurement unit 1A determines whether a "sampling stop" command has been received from the host device 9. If a "sampling stop" command has not been received from the host device 9, the process returns to step S231. If a "sampling stop" command has been received, sampling ends.

[0065] In the past, Figure 11 As shown, the first and second inertial measurement units 1A, 1B are connected in parallel to the host device 9. The host device 9 receives data Dωx3a and Dωx3b from the first and second inertial measurement units 1A, 1B, respectively, averages the received data Dωx3a and Dωx3b, and calculates averaged data Dωx3'. However, this configuration increases the communication load and data processing load (hereinafter referred to as "load") on the host device 9, and further increases the number of signal lines connected to the host device 9.

[0066] In contrast, according to the above method, the first inertial measurement unit 1A receives data Dωx3b and calculates averaged data Dωx3', thereby reducing the load on the host device 9. Furthermore, since the host device 9 is connected only to the first inertial measurement unit 1A, which serves as the master device, the number of signal lines connected to the host device 9 can also be reduced.

[0067] <<Second Sampling Method (Part 2)>>

[0068] In the second sampling method (part 2), as Figure 12As shown, an inertial measurement system 100 is constructed by connecting three inertial measurement units 1, namely, a first inertial measurement unit 1A, a second inertial measurement unit 1B, and a third inertial measurement unit 1C, in series with a host device 9. Specifically, the first inertial measurement unit 1A is connected to the host device 9 via a first communication unit 51, the second communication units 52 of the first inertial measurement unit 1A and the second inertial measurement unit 1B are connected to each other, and the first communication units 51 of the second inertial measurement unit 1B and the third inertial measurement unit 1C are connected to each other.

[0069] Furthermore, the input / output terminal 8 of the first inertial measurement unit 1A is connected to the input / output terminals 8 of the second inertial measurement unit 1B and the third inertial measurement unit 1C. The synchronous clock CLK generated by the oscillation circuit 7 of the first inertial measurement unit 1A is input to the second and third inertial measurement units 1B and 1C. In other words, the first, second, and third inertial measurement units 1A, 1B, and 1C are synchronized by the synchronous clock CLK generated by the first inertial measurement unit 1A. This allows the first, second, and third inertial measurement units 1A, 1B, and 1C to sample data Dωx at the same timing, eliminating variations in sampling timing and enabling highly accurate detection of angular velocity ωx. While the second and third inertial measurement units 1B and 1C include the oscillation circuit 7, this can be omitted. Alternatively, the connection between the oscillation circuit 7 and the input / output terminal 8 can be switched to disconnected depending on the processing mode.

[0070] Initialization Processing

[0071] like Figure 13 As shown in the flowchart, first, in step S311, the host device 9 sends a "3-unit second processing mode" command to the first inertial measurement unit 1A, instructing it to perform sampling in the second processing mode M2 ​​using the three inertial measurement units 1. Next, in step S312, the first inertial measurement unit 1A sets itself as the "master" connected to the host device 9 and selects the second processing mode M2 ​​as the processing mode. As a result, the first inertial measurement unit 1A operates in the master mode of the second processing mode M2.

[0072] Next, in step S313, the first inertial measurement unit 1A transmits a "3-unit second processing mode" command to the second inertial measurement unit 1B. Next, in step S314, the second inertial measurement unit 1B configures itself as "slave unit 1" connected to the first inertial measurement unit 1A, acting as the master unit, and selects the second processing mode M2 ​​as the processing mode. The second inertial measurement unit 1B thus operates in slave mode, in the second processing mode M2. This completes the initialization process.

[0073] Next, in step S315, the second inertial measurement unit 1B transmits a "3-unit second processing mode" command to the third inertial measurement unit 1C. Next, in step S316, the third inertial measurement unit 1C is configured as "slave 2" connected to the second inertial measurement unit 1B as a slave, and the second processing mode M2 ​​is selected as the processing mode. The third inertial measurement unit 1C thus operates in slave mode, in the second processing mode M2. This completes the initialization process.

[0074] - Sampling processing starts -

[0075] like Figure 14 As shown in the flowchart, first, as step S321, the host device 9 sends a "sampling start" command to the first inertial measurement unit 1A. Then, as step S322, the first inertial measurement unit 1A starts sampling the data Dωx. Then, as step S323, the first inertial measurement unit 1A sends a "sampling start" command to the second inertial measurement unit 1B. Then, as step S324, the second inertial measurement unit 1B starts sampling the data Dωx. Then, as step S325, the second inertial measurement unit 1B sends a "sampling start" command to the third inertial measurement unit 1C. Then, as step S326, the third inertial measurement unit 1C starts sampling the data Dωx. At this point, the sampling start processing is completed.

[0076] - Sampling Processing -

[0077] like Figure 15 As shown in the flowchart, first, in step S331, the third inertial measurement unit 1C processes the sampled data Dωx and transmits data Dωx3 (hereinafter referred to as "Dωx3c") as the third signal to the second inertial measurement unit 1B. In the third inertial measurement unit 1C, acting as the terminal slave, this process of outputting data Dωx3c to the host device corresponds to processing in the second processing mode M2 / slave mode. Next, in step S332, the second inertial measurement unit 1B performs computational processing in its second signal processing circuit 4 on the data Dωx3c received from the third inertial measurement unit 1C and the data Dωx3 generated by itself (hereinafter referred to as "Dωx3b"). Specifically, the second signal processing circuit 4 adds Dωx3b + Dωx3c using Dωx3b and Dωx3c sampled at the same time, calculating the added data Dωx3bc as the second signal.

[0078] Next, in step S333, the second inertial measurement unit 1B transmits the calculated added data Dωx3bc to the first inertial measurement unit 1A. In the second inertial measurement unit 1B, which is a slave unit with a lower-level slave (not a terminal device), this process of adding data Dωx3b and Dωx3c and outputting them to the upper-level unit corresponds to processing in the second processing mode M2 / slave mode. Next, in step S334, the first inertial measurement unit 1A performs computations on the added data Dωx3bc received from the second inertial measurement unit 1B and the first signal Dωx3a generated by the first inertial measurement unit 1A in its second signal processing circuit 4. Specifically, Dωx3bc and Dωx3a, sampled at the same time, are averaged using the number of inertial measurement units 1. Specifically, the calculation (Dωx3a + Dωx3bc) / 3 is performed to calculate averaged data Dωx3'. In this way, by performing averaging processing on the three data Dωx3a, Dωx3b, and Dωx3c, noise can be reduced.

[0079] While the above description describes an inertial measurement system 100 in which three inertial measurement units 1 are connected in series to a host device 9, N inertial measurement units 1 may also be connected in series to the host device 9. In this case, N is equal to or greater than 3, and the first inertial measurement unit 1A, serving as the master, averages data sampled at the same time using N in the second signal processing circuit 4.

[0080] Next, in step S335, the first inertial measurement unit 1A transmits the averaged data Dωx3' to the host device 9. This process of calculating and outputting the averaged data Dωx3' corresponds to processing in the second processing mode M2 / master mode. Next, in step S336, the first inertial measurement unit 1A determines whether a "sampling stop" command has been received from the host device 9. If a "sampling stop" command has not been received from the host device 9, the process returns to step S331. If a "sampling stop" command has been received, sampling ends.

[0081] Conventionally, the first, second, and third inertial measurement units 1A, 1B, and 1C are connected in parallel to the host device 9. The host device 9 receives data Dωx3a, Dωx3b, and Dωx3c from the first, second, and third inertial measurement units 1A, 1B, and 1C, averages the received data Dωx3a, Dωx3b, and Dωx3c, and calculates averaged data Dωx3'. However, this configuration increases the load on the host device 9 and, in turn, increases the number of signal lines connected to the host device 9.

[0082] In contrast, according to the above method, the first inertial measurement unit 1A receives data Dωx3b and calculates averaged data Dωx3', thereby reducing the load on the host device 9. Furthermore, the second inertial measurement unit 1B adds Dωx3b and Dωx3c to calculate added data Dωx3bc, thereby also reducing the load on the first inertial measurement unit 1A. By distributing the load in this way, an inertial measurement system 100 is constructed in which the load is less likely to be concentrated in a single location. Furthermore, since the host device 9 is connected only to the first inertial measurement unit 1A, serving as the master unit, the number of signal lines connected to the host device 9 can also be reduced.

[0083] The above describes the inertial measurement unit 1 and inertial measurement system 100. As described above, the inertial measurement unit 1 includes: an inertial sensor 2; a first signal processing circuit 3 that processes the output signal of the inertial sensor 2; a second signal processing circuit 4 that processes the signal processed by the first signal processing circuit 3; a first communication unit 51 and a second communication unit 52 that communicate with external devices, such as a host device 9 or another inertial measurement unit 1; and a mode selection unit 6 that selects a processing mode from a plurality of modes, including a first processing mode M1 and a second processing mode M2. The first processing mode is a mode in which the signal processed by the first signal processing circuit 3 is output from the first communication unit 51 or the second communication unit 52 when the inertial measurement unit 1 is used alone. In the second processing mode M2, when used while connected to another inertial measurement unit 1, second signal processing circuit 4 performs computational processing on the first signal processed by first signal processing circuit 3 and the second signal from the other inertial measurement unit 1 input from one of first communication unit 51 and second communication unit 52, and outputs the processed signal from the other of first communication unit 51 and second communication unit 52. In second processing mode M2, since the inertial measurement unit 1 performs computational processing and outputs the signal, the load on the host device 9, which serves as the output destination, can be reduced. Furthermore, since only one inertial measurement unit 1 is connected to the host device 9, the number of signal lines connected to the host device 9 can also be reduced.

[0084] Furthermore, as described above, the second processing mode M2 ​​performs averaging processing on the first signal and the second signal as a calculation process, thereby reducing noise.

[0085] Furthermore, as described above, the inertial measurement device 1 includes the oscillation circuit 7 that transmits the synchronous clock CLK, and outputs the synchronous clock CLK to other inertial measurement devices 1. This improves the accuracy of inertia detection.

[0086] As described above, the inertial measurement system 100 includes a first inertial measurement unit 1A and a second inertial measurement unit 1B, each of which includes an inertial sensor 2, a first signal processing circuit 3 that processes an output signal from the inertial sensor 2, a second signal processing circuit 4 that processes the signal processed by the first signal processing circuit 3, and a first communication unit 51 and a second communication unit 52 for communicating with an external device such as a host device 9 or another inertial measurement unit 1. The first inertial measurement unit 1A and the second inertial measurement unit 1B are connected via one of the first communication unit 51 and the second communication unit 52. Furthermore, the second inertial measurement unit 1B transmits data Dωx3b, the second signal processed by the first signal processing circuit 3 of the second inertial measurement unit 1B, to the first inertial measurement unit 1A. The first inertial measurement unit 1A then performs computations on data Dωx3a, the first signal processed by the first signal processing circuit 3 of the first inertial measurement unit 1A, and data Dωx3b received from the second inertial measurement unit 1B. The first communication unit 51 and the second communication unit 52 then output the processed signal, averaged data Dωx3′, from the other of the first and second communication units 51 and 52. With this configuration, the first inertial measurement unit 1A performs computations and outputs the data, thereby reducing the load on the host device 9, the output destination. Furthermore, since only one first inertial measurement unit 1A is connected to the host device 9, the number of signal lines connected to the host device 9 can be reduced.

[0087] Furthermore, as described above, inertial measurement system 100 performs averaging processing on data Dωx3a and data Dωx3b as a calculation process, thereby reducing noise.

[0088] Furthermore, as described above, the host device 9 is provided, and the host device 9 is connected to the first inertial measurement unit 1A, and the averaged data Dωx3′ is input from the first inertial measurement unit 1A. This can reduce the load on the host device 9.

[0089] In addition, as described above, the inertial measurement system 100 has a third inertial measurement device 1C, which includes an inertial sensor 2, a first signal processing circuit 3 for processing the output signal of the inertial sensor 2, a second signal processing circuit 4 for processing the signal processed by the first signal processing circuit 3, and a first communication unit 51 and a second communication unit 52 for communicating with an external device such as a host device 9 or other inertial measurement devices 1. Furthermore, the second inertial measurement unit 1B and the third inertial measurement unit 1C are connected via the other of the first communication unit 51 and the second communication unit 52. The third inertial measurement unit 1C transmits data Dωx3c, which is the third signal processed by the first signal processing circuit 3 of the third inertial measurement unit 1C, to the second inertial measurement unit 1B. The second inertial measurement unit 1B performs computations on data Dωx3b, which is the signal processed by the first signal processing circuit 3 of the second inertial measurement unit 1B, and data Dωx3c received from the third inertial measurement unit 1C, and transmits the processed signal, namely added data Dωx3bc, as the second signal to the first inertial measurement unit 1A. This further distributes computational processing between the first inertial measurement unit 1A and the second inertial measurement unit 1B, thereby reducing the load on the first inertial measurement unit 1A.

[0090] While the inertial measurement device and inertial measurement system of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto, and the configurations of the various components can be replaced with any other configuration having the same functionality. Furthermore, any other configurations may be added to the present invention. Furthermore, the above embodiments may be appropriately combined.

Claims

1. An inertial measurement device, characterized in that: It has: Inertial sensors; a first signal processing circuit for processing an output signal of the inertial sensor; a second signal processing circuit for processing the signal processed by the first signal processing circuit; a first communication unit and a second communication unit that communicate with an external device provided outside the inertial measurement unit and are provided at a subsequent stage of the second signal processing circuit; as well as a mode selection unit that selects a processing mode from a plurality of modes including a first processing mode and a second processing mode, The first processing mode is a mode in which the signal processed by the first signal processing circuit is output from the first communication unit or the second communication unit when used as a single unit. The second processing mode is a mode in which, when used in a state connected to another inertial measurement device, the second signal processing circuit performs computational processing on the first signal processed by the first signal processing circuit and the second signal from the other inertial measurement device input from one of the first communication unit and the second communication unit, and outputs the computationally processed signal from the other of the first communication unit and the second communication unit.

2. The inertial measurement device according to claim 1, wherein The second processing mode performs averaging processing on the first signal and the second signal as the calculation processing.

3. The inertial measurement device according to claim 2, characterized in that The inertial measurement device includes an oscillation circuit that transmits a synchronous clock, and outputs the synchronous clock to the other inertial measurement device.

4. An inertial measurement system, characterized in that: The device comprises a first inertial measurement unit and a second inertial measurement unit, each of the first inertial measurement unit and the second inertial measurement unit comprising: an inertial sensor; a first signal processing circuit for processing an output signal of the inertial sensor; and a second signal processing circuit for processing the signal processed by the first signal processing circuit. and a first communication unit and a second communication unit provided at a subsequent stage of the second signal processing circuit, the first communication unit and the second communication unit communicating with an external device provided outside the first inertial measurement unit and the second inertial measurement unit, The first inertial measurement unit and the second inertial measurement unit are connected via one of the first communication unit and the second communication unit. The second inertial measurement unit transmits the second signal processed by the first signal processing circuit of the second inertial measurement unit to the first inertial measurement unit. The first inertial measurement unit performs computational processing on the first signal processed by the first signal processing circuit of the first inertial measurement unit and the second signal received from the second inertial measurement unit, and outputs the processed signal from the other of the first communication unit and the second communication unit.

5. The inertial measurement system according to claim 4, characterized in that The calculation process includes performing averaging processing on the first signal and the second signal.

6. The inertial measurement system according to claim 4 or 5, characterized in that The inertial measurement system includes a host device connected to the first inertial measurement unit and inputting the processed signal from the first inertial measurement unit.

7. The inertial measurement system according to claim 4 or 5, characterized in that The inertial measurement system includes a third inertial measurement unit, wherein the third inertial measurement unit includes: an inertial sensor; a first signal processing circuit that processes an output signal of the inertial sensor; and a second signal processing circuit that processes the signal processed by the first signal processing circuit. and a first communication unit and a second communication unit provided at a subsequent stage of the second signal processing circuit, the first communication unit and the second communication unit communicating with an external device provided outside the third inertial measurement unit, The second inertial measurement unit and the third inertial measurement unit are connected via the other of the first communication unit and the second communication unit. The third inertial measurement unit transmits the third signal processed by the first signal processing circuit of the third inertial measurement unit to the second inertial measurement unit. The second inertial measurement unit performs computation on the signal processed by the first signal processing circuit of the second inertial measurement unit and the third signal received from the third inertial measurement unit, and transmits the processed signal as the second signal to the first inertial measurement unit.

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