Sensor control device

Abstract

The sensor control device comprises: a plurality of driving units for vibrating a transducer of each of the plurality of ultrasonic sensors; a driving signal generating unit for generating a driving signal capable of vibrating each of the plurality of transducers; a control unit having a control signal output unit for outputting a control signal serving as an input indication of the driving signal for the transducer to each of the plurality of driving units; and a bus for connecting the control unit and the plurality of driving units in a daisy chain manner, wherein bidirectional communication of communication data having a data structure of a first frequency band on which sound data can be overlapped is performed between the control unit and each of the plurality of driving units based on a predetermined time division, wherein control data based on the control signal is included in the first frequency band.

Description

Technical Field

[0001] The present disclosure relates to a sensor control device that drives a plurality of ultrasonic sensors that detect objects around a vehicle. Background Art

[0002] In the past, in order to support the driving of the vehicle, a sensor for detecting objects around the vehicle was installed on the vehicle. In order to detect the surroundings of the vehicle over a wide range, for example, a plurality of such sensors were installed on the vehicle. As a technology related to a vehicle equipped with such a plurality of sensors, there is a technology described in JP2003-141693A, for example.

[0003] JP2003-141693A describes a vehicle safety confirmation device that confirms driving safety by installing obstacle sensors at the rear, front, or side of a traveling body in isolation from each other. In the vehicle safety confirmation device, a plurality of obstacle sensors (a lower right obstacle sensor, an upper right obstacle sensor, an upper left obstacle sensor, a lower left obstacle sensor, and obstacle sensors installed at other locations) are provided on the traveling body, and these obstacle sensors are connected to a control unit that manages the overall operation of the vehicle safety confirmation device via a switching connection unit. Summary of the invention

[0004] In the technology described in JP2003-141693A, a plurality of obstacle sensors are arranged at the rear of a large vehicle and are individually connected to a control unit in a one-to-one correspondence. On the other hand, in recent years, in order to reduce fuel consumption in vehicles, lightweight and miniaturized loading components are sought. Considering the loading on the vehicle, in the technology described in JP2003-141693A, since each of the plurality of obstacle sensors is individually connected to the control unit in a one-to-one correspondence, the weight of the connecting wire (cable) increases correspondingly to the number of obstacle sensors.

[0005] An embodiment of the present invention is a sensor control device that can be made lightweight.

[0006] The sensor control device disclosed in the present invention is a sensor control device that drives multiple ultrasonic sensors for detecting objects around a vehicle, and includes: multiple driving units that vibrate the transducers of each of the multiple ultrasonic sensors; a driving signal generating unit that generates a driving signal that can cause each of the multiple transducers to vibrate; a control unit that has a control signal output unit that outputs a control signal that serves as an input indication of the driving signal for the transducer to each of the multiple driving units; and a bus that connects the control unit and the multiple driving units in a daisy chain type, and performs bidirectional communication of communication data composed of a data structure having a first frequency band in which sound data can be overlapped based on a predetermined time division between the control unit and each of the multiple driving units, and the control data based on the control signal is included in the first frequency band.

[0007] In this case, a bus that can be used for transmitting and receiving sound data can be used in the control of the ultrasonic sensor. In addition, since the bus is used to connect the plurality of drive units, the control of the plurality of ultrasonic sensors can be unified. Furthermore, since the drive signal generating unit and the plurality of drive units are connected in a daisy chain type, the connection can be simplified and the weight can be reduced.

[0008] In one embodiment of the sensor control device, the drive data based on the drive signal may be included in a second frequency band different from the first frequency band in the communication data transmitted from the control unit to the drive unit.

[0009] In this case, even in a case where the drive signal generation unit is included in the control unit, for example, the drive signal can be appropriately transmitted to the drive unit.

[0010] In addition, in one embodiment of the sensor control device, the driving unit can be configured to generate a reflection signal based on the reflection wave obtained by the ultrasonic sensor, and reflection data based on the reflection signal is included in a second frequency band different from the first frequency band in the communication data transmitted from the driving unit to the control unit.

[0011] In this case, even when the function unit for analyzing the reflected wave is configured to be included in the control unit, the reflected signal can be appropriately transmitted to the control unit.

[0012] Furthermore, in one embodiment of the sensor control device, the bus may be an in-vehicle audio bus.

[0013] In this case, an audio bus that transmits sound signals between audio devices mounted on the vehicle can be used to control the ultrasonic sensor, so that cost reduction can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an example of installing an ultrasonic sensor in a vehicle.

[0015] Figure 2 : is a block diagram showing the structure of the sensor control device.

[0016] Figure 3 1 and 2 are signal waveforms of various parts showing the operation of the sensor control device.

[0017] Figure 4 This is a timing chart related to the transmission and reception of communication data. DETAILED DESCRIPTION

[0018] The sensor control device of the present disclosure controls the driving of a plurality of ultrasonic sensors mounted on a vehicle, and is designed to be lightweight. Hereinafter, a sensor control device 1 of the present embodiment will be described.

[0019] Figure 1 1 is a diagram showing an example of loading an ultrasonic sensor 3 controlled by a sensor control device 1 of the present embodiment on a vehicle 2. A plurality of ultrasonic sensors 3 for detecting objects around the vehicle 2 are loaded on the vehicle 2. Objects around the vehicle 2 refer to objects that the driver of the vehicle 2 should pay attention to when the vehicle 2 is moving or parked. Such objects are not limited to stationary objects, but also include other moving objects such as vehicles, people, and bicycles. The ultrasonic sensor 3 detects the presence or absence of an object and the distance to the object based on the time from the emission of ultrasonic waves to the time when the ultrasonic waves are reflected by the object and return. Such ultrasonic sensors are well known, so detailed descriptions are omitted.

[0020] exist Figure 1 In the example, the ultrasonic sensors 3 are provided at six locations, namely, the front left end, the front center, the front right end, the rear left end, the rear center, and the rear right end of the vehicle 2. Of course, the ultrasonic sensors 3 may be provided at locations other than these, and some of the six ultrasonic sensors 3 may be omitted. The sensor control device 1 controls the driving of such ultrasonic sensors 3.

[0021] Figure 2 : is a block diagram schematically showing the structure of the sensor control device 1 . Figure 3 : is a signal waveform of each part showing the operation of the sensor control device 1. Figure 2 As shown in FIG. 1 , the sensor control device 1 includes functional units such as a drive unit 10, a drive signal generation unit 20, a control unit 30, and a bus 40. In the present embodiment, the drive signal generation unit 20 is provided in the control unit 30.

[0022] The driving unit 10 causes each transducer 3A (transducer) of the ultrasonic sensor 3 to vibrate. The transducer 3A is built into the ultrasonic sensor 3, and has a function of converting an electrical signal into an ultrasonic wave, and a function of converting an ultrasonic wave into an electrical signal. Such a transducer 3A is well known, and therefore a detailed description thereof is omitted. The driving unit 10 causes the transducer 3A to vibrate according to a control signal from a control signal output unit 31 described later. Here, the driving unit 10 is provided in a one-to-one correspondence with respect to the transducer 3A. Therefore, the driving unit 10 is provided in accordance with the number of the transducers 3A. In the present embodiment, since a plurality (six) of ultrasonic sensors 3 are provided, a plurality (six) of driving units 10 are also provided.

[0023] The drive signal generating unit 20 generates a drive signal that can vibrate each of the plurality of transducers 3A. As described above, each of the plurality of ultrasonic sensors 3 is provided with a transducer 3A, and each of the plurality of drive units 10 vibrates the plurality of transducers 3A. The drive signal generated by the drive signal generating unit 20 is equivalent to a signal that vibrates the transducer 3A provided in each of the plurality of drive units 10. The drive signal generating unit 20 generates such a drive signal and outputs it to the drive unit 10. Figure 3 An example of a drive signal is shown in FIG. Figure 3 In the example of FIG. 1 , a driving signal is shown that is composed of a pulse signal that becomes high level corresponding to the time when the transducer 3A is vibrated. The transducer 3A radiates ultrasonic waves and also obtains reflected waves, so the driving signal is output at a predetermined time instead of being output constantly. The driving signal generating unit 20 can output the driving signal to multiple driving units 10 at the same time, or can set a time difference and output the driving signal to each driving unit 10 individually. In either case, Figure 3 As shown in FIG. 1 , the ultrasonic sensor 3 outputs ultrasonic waves according to the drive signal. The drive unit 10 receives the drive signal from the drive signal generator 20, improves the drivability of the drive signal through a driver (not shown), and drives the transducer 3A.

[0024] In this embodiment, the control unit 30 is provided with a control signal output unit 31 in addition to the drive signal generation unit 20. The control signal output unit 31 outputs a control signal serving as an input instruction of a drive signal to the transducer 3A to each of the plurality of drive units 10.

[0025] Here, in this embodiment, if Figure 2As shown, the plurality of drive units 10 respectively include a drive signal acquisition unit 11, a switch 12, and a signal processing unit 13. The drive signal acquisition unit 11 acquires the drive signal generated by the drive signal generation unit 20. The switch 12 is provided between the drive signal acquisition unit 11 and the ultrasonic sensor 3 (transducer 3A), and transmits the drive signal from the drive signal acquisition unit 11 to the transducer 3A and cuts off the drive signal from the drive signal acquisition unit 11 to the transducer 3A. The signal processing unit 13 acquires the control signal output from the control signal output unit 31, and controls the on / off state of the switch 12.

[0026] Therefore, when the control signal obtained by the signal processing unit 13 from the control signal output unit 31 is a signal indicating that the switch 12 is changed to a closed state, the drive signal is transmitted from the drive signal acquisition unit 11 to the transducer 3A. When the control signal obtained by the signal processing unit 13 from the control signal output unit 31 is a signal indicating that the switch 12 is changed to an open state, the drive signal is cut off from the drive signal acquisition unit 11 to the transducer 3A.

[0027] The bus 40 connects the control unit 30 and the plurality of drive units 10 in a daisy chain. In the present embodiment, the control unit 30 has the above-mentioned drive signal generating unit 20 and the control signal output unit 31. The plurality of drive units 10 have the drive signal acquiring unit 11, the switch 12 and the signal processing unit 13 as described above. Daisy chain connection refers to a method of connecting each of the plurality of devices in series in the manner of beads, which is one of the methods of connecting electrical devices and the like through cables. Therefore, with respect to the plurality of devices connected in the manner of beads, the further downstream the signal is from the output source of the signal, the more it needs to be relayed by other devices (upstream devices) to be transmitted. There are various specifications in the connection using such a daisy chain type, but since it is well known, the description is omitted. In the present embodiment, the control unit 30 and the plurality of drive units 10 are connected in the manner of beads.

[0028] The control unit 30 and each of the plurality of drive units 10 perform bidirectional communication of communication data via the bus 40. The bus 40 is configured to have a twisted pair cable, and bidirectional communication is performed using the twisted pair cable, for example, LVDS (Low Amplitude Differential Signaling). Figure 1 As shown in the figure, the wiring is arranged in the vehicle 2. Therefore, the control unit 30 and each of the plurality of drive units 10 provided in each part of the vehicle 2 can transmit and receive communication data.

[0029] exist Figure 4An example of communication data performed through bidirectional communication between the control unit 30 and each of the multiple drive units 10 is shown in FIG. 1 . Here, in order to facilitate understanding, communication data transmitted from the control unit 30 to a specified drive unit 10 among the multiple drive units 10 is shown as first transmission data, communication data transmitted from the control unit 30 to another specified drive unit 10 among the multiple drive units 10 that is different from the specified drive unit is shown as second transmission data, communication data transmitted from the specified drive unit 10 to the control unit 30 is shown as first reception data, and communication data transmitted from the another specified drive unit 10 to the control unit 30 is shown as second reception data. Each of these data is communicated based on a predetermined time division. That is, as Figure 4 As shown, each data is communicated while being arranged in time. Furthermore, communication data is transmitted and received based on time division, but by setting the cycle of each data to, for example, about tens of microseconds, the delay associated with the transmission and reception of each data can be ignored.

[0030] In addition, each of these data in the present embodiment is composed of a data structure having a first frequency band and a second frequency band. The first frequency band is a frequency band in which sound data can be overlapped, and sound data can be sent and received between audio modules installed in the vehicle 2 via the bus 40. The audio module installed in the vehicle 2 is equivalent to a device such as a player that reproduces sound, a speaker that outputs sound, and a microphone that collects sound. Of course, it can also be configured to include devices such as acceleration sensors. Between such devices, the transmission of sound signals is also configured to be carried out via the bus 40. Furthermore, in practice, the bus 40 can be used or not used in the transmission and reception of sound signals between such devices.

[0031] For example, when bus 40 is used to send and receive sound data between a player and a speaker or between a microphone and a speaker, communication data can be constructed in a manner that includes data showing identification information of a device that can determine the destination of transmission in the second frequency band and includes sound data used by the device of the destination of transmission in the first frequency band.

[0032] The control signal output from the control signal output unit 31 is converted into control data based on the control signal, and the control data is transmitted from the control unit 30 to each of the drive units 10 in a state included in the first frequency band. Therefore, the signal processing unit 13 obtains the control signal from the control data included in the first frequency band of the first transmission data or the second transmission data.

[0033] In the present embodiment, the drive signal generation unit 20 is also included in the control unit 30. Therefore, the drive signal generated by the drive signal generation unit 20 is converted into drive data based on the drive signal, and the drive data is included in the second frequency band different from the first frequency band in the communication data (the first transmission data or the second transmission data) transmitted from the control unit 30 to the drive unit 10. Therefore, the drive signal acquisition unit 11 acquires the drive signal from the drive data included in the second frequency band of the first transmission data or the second transmission data.

[0034] On the other hand, when the ultrasonic wave radiated from the ultrasonic sensor 3 reaches an object, Figure 3 As shown in FIG. 1 , the reflected wave is reflected by the object and returns to the transducer 3A. The reflected wave is converted into an electrical signal by the transducer 3A, and the converted electrical signal is transmitted to the signal processing unit 13. The signal processing unit 13 generates a reflected signal based on the electrical signal (the reflected wave obtained by the ultrasonic sensor 3). Furthermore, the reflected signal is converted into reflection data based on the reflected signal, and is included in the communication data (the first received data or the second received data) transmitted from the drive unit 10 to the control unit 30 in a second frequency band different from the first frequency band.

[0035] The reflection data is transmitted from the driving unit 10 to the analyzing unit 50 via the bus 40. The analyzing unit 50 obtains a reflection signal from the reflection data included in the second frequency band of the first reception data or the second reception data. The analyzing unit 50 calculates the distance from the vehicle 2 (ultrasonic sensor 3) to the object based on the reflection signal.

[0036] The analysis unit 50 calculates the presence or absence of an object and the distance to the object based on the drive signal and the electrical signal. That is, the distance to the object is calculated based on the time difference from outputting the ultrasonic wave as an output wave to obtaining the reflected wave. In addition, the transducer 3A is configured to obtain the reflected wave, but the drive unit 10 (signal processing unit 13) amplifies the reflected wave and transmits the electrical signal with a predetermined potential difference as the amplitude to the analysis unit 50.

[0037] Here, in this embodiment, an on-board audio bus is used as such a bus 40. The on-board audio bus is mounted on the vehicle 2 and is used for transmitting and receiving sound signals. In the sensor control device 1, the on-board audio bus is used to control the driving of the ultrasonic sensor 3. Specifically, the bus 40 can use A2B (registered trademark). As a result, the weight reduction and cost reduction of the bus 40 can be achieved.

[0038] With the above configuration, the sensor control device 1 can control the plurality of ultrasonic sensors 3. Furthermore, since the control unit 30 and the plurality of drive units 10 are daisy-chain connected using the bus 40, wiring can be simplified and the sensor control device 1 can be reduced in weight.

[0039] [Other implementation methods]

[0040] In the above embodiment, the bus 40 is described as being configured using an in-vehicle audio bus, but the bus 40 may also be configured using a cable of an in-vehicle network.

[0041] In the above embodiment, the analysis unit 50 for calculating the distance to the object is provided, but the configuration may be configured without the analysis unit 50. In such a case, the sensor control device 1 may be configured to transmit the electrical signal converted from the reflected wave by the transducer 3A to the device for calculating the distance to the object.

[0042] In the above embodiment, the drive signal generating unit 20 is described as being included in the control unit 30, but the drive signal generating unit 20 can also be provided separately from the control unit 30. In this case, the drive data based on the drive signal can also be transmitted to the drive unit 10 via the bus 40. Alternatively, the drive signal generating unit 20 can also be configured to be included in the drive unit 10. In this case, the drive signal acquiring unit 11 acquires the drive signal, and can output the drive signal to the transducer 3A according to the on-off control of the switch 12 by the signal processing unit 13.

[0043] In the above embodiment, the reflection data based on the reflection signal is described as being included in the second frequency band. However, the reflection data based on the reflection signal may be transmitted from the drive unit 10 to the control unit 30 without using the bus 40 .

[0044] In the above embodiment, the communication data is described as having a data structure including the first frequency band and the second frequency band. However, the communication data may also have a data structure including a frequency band other than the first frequency band and the second frequency band.

[0045] The present disclosure can be used in a sensor control device that drives a plurality of ultrasonic sensors that detect objects around a vehicle.

Claims

1. A sensor control device that drives a plurality of ultrasonic sensors for detecting objects around a vehicle, characterized in that: have: A plurality of driving units for vibrating a transducer included in each of the plurality of ultrasonic sensors; a drive signal generating unit for generating a drive signal capable of vibrating each of the plurality of transducers; a control unit having a control signal output unit, the control signal output unit outputting a control signal serving as an input instruction of the drive signal for the transducer to each of the plurality of drive units; as well as A bus is provided to connect the control unit and the plurality of drive units in a daisy-chain manner, and bidirectional communication of communication data having a data structure of a first frequency band on which sound data can be superimposed is performed between the control unit and each of the plurality of drive units based on a predetermined time division, Control data based on the control signal is included in the first frequency band, The driving unit generates a reflection signal based on the reflection wave obtained by the ultrasonic sensor, Reflection data based on the reflection signal is included in a second frequency band different from the first frequency band in the communication data transmitted from the driving unit to the control unit.

2. The sensor control device according to claim 1, wherein: Driving data based on the driving signal is included in a second frequency band different from the first frequency band in the communication data transmitted from the control unit to the driving unit.

3. The sensor control device according to claim 1 or 2, wherein: The bus is an in-vehicle audio bus.

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