Detection device, steering device

Abstract

The detection device includes: multiple sensors that detect the value of the detection object; and a processing unit that processes the detection signals output respectively from the multiple sensors, and the cycle of outputting the detection signals of some sensors among the multiple sensors is shorter than the cycle of outputting the detection signals of other sensors among the multiple sensors.

Description

Technical Field

[0001] The invention relates to a detection device and a steering device. Background Art

[0002] In recent years, technologies have been proposed that allow the steering assist function to remain functional even when an abnormality occurs in the sensor output signal. For example, the power steering device described in Patent Document 1 is constructed as follows. Specifically, it comprises a steering torque sensor, a steering angle sensor, and a motor rotation angle sensor, each of which has at least two redundant systems. Steering assist control is typically performed based on the steering torque detection signal, steering angle detection signal, and motor rotation angle detection signal of one of the two systems. Furthermore, the steering torque sensors, steering angle sensors, and motor rotation angle sensors of the two systems are redundantly monitored, and if an abnormality is detected through the redundant monitoring, a switch is made to an alternative signal.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6283737 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] From the perspective of safety, sensors used in electric power steering systems are required to be redundant. In response to this requirement, the processing load on devices that process detection signals from sensors, such as detecting failures of redundant sensors, increases.

[0008] An object of the present invention is to provide a detection device and the like that can suppress the processing load of a device that processes detection signals of redundant sensors.

[0009] Means for solving problems

[0010] One method is a detection device comprising: a plurality of sensors that detect a value of a detection object; and a processing unit that processes detection signals outputted from the plurality of sensors, wherein a period for outputting detection signals of some of the plurality of sensors is shorter than a period for outputting detection signals of other sensors.

[0011] Here, at least four of the sensors may be provided, and the part of the sensors may be two of the at least four sensors.

[0012] In addition, the processing unit may use the detection signals of the two sensors to diagnose whether the two sensors are normal, and when the two sensors are diagnosed as normal, output the detection signal of any one of the two sensors as a signal representing the value of the detection object.

[0013] Furthermore, when the two sensors are not diagnosed as being normal, the processing unit may output a detection signal of any one of the other sensors as a detection signal indicating a value of the detection target.

[0014] Furthermore, the amount of information transmitted by the detection signals of the two sensors is greater than the amount of information transmitted by the detection signals of the other sensors.

[0015] Alternatively, at least four of the sensors may be provided, and the part of the sensors may be one of the at least four sensors.

[0016] In addition, the processing unit may use the detection signal of the one sensor and the detection signal of one of the other sensors to diagnose whether the one sensor and the one sensor are normal, and when it is diagnosed that the one sensor and the one sensor are normal, the detection signal of the one sensor is output as a detection signal representing the value of the detection object.

[0017] Furthermore, when the one sensor and the one sensor are not diagnosed as being normal, the processing unit may output detection signals of sensors other than the one sensor among the other sensors as detection signals indicating the value of the detection target.

[0018] Furthermore, the amount of information transmitted by the detection signal of the one sensor is greater than the amount of information transmitted by the detection signals of the other sensors.

[0019] Another embodiment of the present invention is a detection device comprising: a plurality of sensors that detect the value of a detection object; and a processing unit that processes detection signals output respectively from the plurality of sensors, wherein the amount of information sent by the detection signals of some of the plurality of sensors is greater than the amount of information sent by the detection signals of other sensors among the plurality of sensors.

[0020] Another aspect of the present invention is a steering system including: the detection device of the above aspect; and a control unit that controls the operation of the electric motor using a value detected by the detection device.

[0021] Effects of the Invention

[0022] According to the present invention, it is possible to suppress the processing load on a device that processes detection signals from redundant sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a diagram showing an example of a schematic configuration of an electric power steering device according to the first embodiment.

[0024] Figure 2 This is a diagram showing an example of a schematic configuration of a sensor unit and a control device.

[0025] Figure 3 This is a diagram showing an example of the first period, the second period, the third period, and the fourth period in the first embodiment.

[0026] Figure 4 This is a diagram showing an example of the first period, the second period, the third period, and the fourth period in the detection device according to the second embodiment.

[0027] Figure 5 This is a diagram showing an example of the amount of information transmitted by the first, second, third, and fourth cycles and the first, second, third, and fourth signals TS1, TS2, TS3, and TS4 in the detection device of the third embodiment.

[0028] Figure 6 This is a diagram showing an example of the amount of information transmitted by the first cycle, the second cycle, the third cycle, and the fourth cycle, and the first signal, the second signal, the third signal, and the fourth signal in the detection device of the fourth embodiment.

[0029] Figure 7 This is a diagram showing an example of a schematic configuration of a detection device according to a fifth embodiment.

[0030] Figure 8 This is a diagram showing an example of the amount of information transmitted by the first cycle, the second cycle, the third cycle, and the fourth cycle, and the first signal, the second signal, the third signal, and the fourth signal in the detection device of the fifth embodiment.

[0031] Figure 9 This is a diagram showing an example of the amount of information transmitted by the first cycle, the second cycle, the third cycle, and the fourth cycle, and the first signal, the second signal, the third signal, and the fourth signal in the detection device of the sixth embodiment.

[0032] Figure 10 This is a diagram showing an example of the amount of information transmitted by the first cycle, the second cycle, the third cycle, and the fourth cycle, and the first signal, the second signal, the third signal, and the fourth signal in the detection device of the seventh embodiment. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] <First embodiment>

[0035] Figure 1 This is a diagram showing an example of a schematic configuration of the electric power steering device 1 according to the first embodiment.

[0036] The electric power steering system 1 (hereinafter sometimes simply referred to as the "steering system 1") is a steering system for arbitrarily changing the direction of travel of a vehicle. In this embodiment, a structure applied to an automobile as an example of a vehicle is illustrated. Figure 1 This is a picture of the car viewed from the front.

[0037] The steering system 1 includes a steering wheel 11 that the driver operates to change the direction of travel of the vehicle, and a steering shaft 12 integrally provided with the steering wheel 11. The steering system 1 also includes an upper connecting shaft 13 connected to the steering shaft 12 via a universal joint 13a, and a lower connecting shaft 18 connected to the upper connecting shaft 13 via a universal joint 13b. The lower connecting shaft 18 rotates in conjunction with the rotation of the steering wheel 11.

[0038] The steering system 1 also includes tie rods 14 connected to the left and right front wheels 2, which serve as turning wheels, and a rack shaft 15 connected to the tie rods 14. Furthermore, the steering system 1 includes a pinion shaft 16 having a pinion 16a formed thereon. The pinion 16a, together with rack teeth 15a formed on the rack shaft 15, constitutes a rack and pinion mechanism.

[0039] The steering system 1 also includes a gearbox 17 that covers the rack teeth 15a and the pinion gear 16a. The pinion shaft 16 is connected to the lower connecting shaft 18 via a torsion bar 30 within the gearbox 17. Furthermore, a sensor unit 19 is provided within the gearbox 17 to detect the steering torque applied to the steering wheel 11 based on the relative rotational angle between the lower connecting shaft 18 and the pinion shaft 16, that is, the amount of twisting of the torsion bar 30.

[0040] The steering system 1 also includes an electric motor 20 supported by the gear box 17 , and a speed reduction mechanism 21 that reduces the speed of the driving force of the electric motor 20 and transmits the reduced speed to the lower connecting shaft 18 .

[0041] Furthermore, the steering system 1 includes a control device 100 that controls the operation of the electric motor 20. The control device 100 receives an output signal from the sensor unit 19 described above.

[0042] Figure 2 It is a diagram showing an example of a schematic configuration of the sensor unit 19 and the control device 100 .

[0043] The control device 100 is an arithmetic logic operation circuit composed of a CPU, ROM, RAM, EEPROM (Electrically Erasable & Programmable Read Only Memory), and the like.

[0044] The control device 100 includes a processing unit 110 that processes an output signal from the sensor unit 19 , and a control unit 170 that controls the operation of the electric motor 20 based on the signal output from the processing unit 110 .

[0045] The processing unit 110 and the sensor unit 19 together constitute a detection device 200 for detecting the steering torque. The detection device 200 will be described in detail later.

[0046] The control unit 170 sets a target current to be supplied to the electric motor 20 , and performs feedback control so that the target current coincides with the detected actual current supplied to the electric motor 20 .

[0047] (Detection device 200)

[0048] [Sensor unit 19]

[0049] The sensor unit 19 includes a first sensor 211, a second sensor 212, a third sensor 213, and a fourth sensor 214. The structures of the first sensor 211, the second sensor 212, the third sensor 213, and the fourth sensor 214 differ only in aspects described in detail below, but are essentially the same. Hereinafter, when the first sensor 211, the second sensor 212, the third sensor 213, and the fourth sensor 214 do not need to be distinguished, they may be collectively referred to as the sensor 210.

[0050] The first sensor 211, the second sensor 212, the third sensor 213, and the fourth sensor 214 can each be implemented, for example, by a Hall IC having the first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the fourth magnetic sensor described in Japanese Patent Application Publication No. 2018-95223 filed by the present applicant. That is, the sensor 210 is formed by integrating a Hall element (not shown) for detecting the magnetic flux density in the magnetic circuit formed by a magnet (not shown) mounted on the lower connecting shaft 18 and a magnetic yoke (not shown) fixed to the pinion shaft 16, with an operational amplifier (not shown). The sensor 210 amplifies the Hall voltage output from the Hall element and performs signal processing, thereby outputting a signal corresponding to the magnetic flux density.

[0051] In the following description, the detection signal output from the first sensor 211 is referred to as "first signal TS1," and the detection signal output from the second sensor 212 is referred to as "second signal TS2." Furthermore, the detection signal output from the third sensor 213 is referred to as "third signal TS3," and the detection signal output from the fourth sensor 214 is referred to as "fourth signal TS4." When it is not necessary to distinguish between the first signal TS1, the second signal TS2, the third signal TS3, and the fourth signal TS4, they may be collectively referred to as signal TS.

[0052] [Processing Unit 110]

[0053] The processing unit 110 includes a diagnosis unit 140 that diagnoses failures of the first sensor 211, the second sensor 212, the third sensor 213, and the fourth sensor 214. The processing unit 110 also includes a switching unit 160 that switches between using the first signal TS1 output from the first sensor 211 and the third signal TS3 output from the third sensor 213 as the torque signal Td.

[0054] [Diagnosis unit 140]

[0055] The first signal TS1 , the second signal TS2 , the third signal TS3 , and the fourth signal TS4 are input to the diagnosis unit 140 .

[0056] The diagnosis unit 140 uses the first signal TS1 and the second signal TS2 to diagnose whether the first sensor 211 and the second sensor 212 are normal or whether a failure has occurred in the first sensor 211 or the second sensor 212 .

[0057] Furthermore, the diagnosis unit 140 uses the third signal TS3 and the fourth signal TS4 to diagnose whether the third sensor 213 and the fourth sensor 214 are normal or whether the third sensor 213 or the fourth sensor 214 has failed.

[0058] [Switching unit 160]

[0059] When the diagnosis unit 140 diagnoses that the first sensor 211 and the second sensor 212 are not faulty, the switching unit 160 outputs the first signal TS1 output from the first sensor 211 as the torque signal Td.

[0060] In addition, when the diagnostic unit 140 diagnoses that the first sensor 211 or the second sensor 212 has failed, and when the diagnostic unit 140 diagnoses that the third sensor 213 and the fourth sensor 214 have not failed, the switching unit 160 outputs the third signal TS3 output from the third sensor 213 as the torque signal Td.

[0061] Furthermore, when the diagnosis unit 140 diagnoses that the first sensor 211 , the second sensor 212 , the third sensor 213 , or the fourth sensor 214 has failed, the switch unit 160 outputs a signal indicating this.

[0062] Hereinafter, a communication method between the first sensor 211 , the second sensor 212 , the third sensor 213 , and the fourth sensor 214 and the control device 100 will be described.

[0063] As described above, the first sensor 211, the second sensor 212, the third sensor 213, and the fourth sensor 214 respectively output the first signal TS1, the second signal TS2, the third signal TS3, and the fourth signal TS4 to the control device 100. Hereinafter, the period during which the first sensor 211 outputs the first signal TS1, the period during which the second sensor 212 outputs the second signal TS2, the period during which the third sensor 213 outputs the third signal TS3, and the period during which the fourth sensor 214 outputs the fourth signal TS4 may be referred to as the first period, the second period, the third period, and the fourth period, respectively.

[0064] In the detection device 200 of the first embodiment, the amount of information transmitted by the first to fourth signals TS1 to TS4 is the same, for example, 12 bits or 16 bits.

[0065] Figure 3 This is a diagram showing an example of the first period, the second period, the third period, and the fourth period in the first embodiment.

[0066] In the detection device 200 involved in the first embodiment, the first period is the same as the second period, and the third period is the same as the fourth period, and the third period and the fourth period are set to be longer than the first period and the second period. For example, the third period and the fourth period can be exemplified as integer multiples of the first period and the second period. For example, when the first period and the second period are 1 msec, the third period and the fourth period can be exemplified as 2 msec, 3 msec, 4 msec, or 5 msec. Alternatively, when the first period and the second period are 0.5 msec, the third period and the fourth period can be exemplified as 1 msec, 1.5 msec, 2 msec, or 2.5 msec.

[0067] In this case, the diagnostic unit 140 of the control device 100 obtains the first signal TS1 and the second signal TS2 in a first cycle and diagnoses whether the first sensor 211 and the second sensor 212 are normal in the first cycle. Meanwhile, the diagnostic unit 140 obtains the third signal TS3 and the fourth signal TS4 in a third cycle and diagnoses whether the third sensor 213 and the fourth sensor 214 are normal in the third cycle.

[0068] Furthermore, while the first sensor 211 and the second sensor 212 are diagnosed as being normal, the switching unit 160 outputs the first signal TS1 as the torque signal Td at the first cycle.

[0069] As described above, the detection device 200 includes: first to fourth sensors 211 to 214, which are examples of a plurality of sensors that detect the steering torque applied to the steering wheel 11 as a detection target value; and a processing unit 110 that processes first to fourth signals TS1 to TS4, which are examples of detection signals outputted from the first to fourth sensors 211 to 214, respectively. Furthermore, in the detection device 200, a first cycle, which is a cycle of outputting signals TS from the first and second sensors 211 and 212, which are examples of some of the first to fourth sensors 211 to 214, is shorter than a third cycle, which is a cycle of outputting signals TS from the third and fourth sensors 213 and 214, which are examples of other sensors among the first to fourth sensors 211 to 214.

[0070] In the detection device 200 configured in this manner, the processing load on the processing unit 110 is reduced compared to a case where the first to fourth cycles are identical to the first cycle, and the processing unit 110 of the control device 100 diagnoses the normal operation of the first sensor 211 and the second sensor 212, and the normal operation of the third sensor 213 and the fourth sensor 214, according to the first cycle. This has the effect of reducing the processing load on the control device 100 even when the communication cycle between the sensor 210 and the control device 100 is increased in speed to improve the steering feel of the steering system 1.

[0071] Furthermore, in such a configuration, even if the first sensor 211 or the second sensor 212 fails, the operation of the electric motor 20 can be controlled using the third signal TS3 from the third sensor 213. Therefore, the above configuration does not reduce the safety of the steering system 1.

[0072] Furthermore, in the first embodiment described above, the switching unit 160 outputs the first signal TS1 output from the first sensor 211 as the torque signal Td when the diagnostic unit 140 diagnoses that the first sensor 211 and the second sensor 212 are not faulty. However, this configuration is not particularly limiting. The switching unit 160 may output the second signal TS2 as the torque signal Td instead of the first signal TS1. Furthermore, when the diagnostic unit 140 diagnoses that the third sensor 213 and the fourth sensor 214 are not faulty, the switching unit 160 may output the fourth signal TS4 as the torque signal Td instead of the third signal TS3 output from the third sensor 213.

[0073] Furthermore, in the first embodiment described above, four sensors 210 are provided, namely, first sensor 211 to fourth sensor 214. However, the present invention is not particularly limited to this configuration. Five or more sensors 210 may be provided. In such a configuration, the period of the output signal TS of sensors 210 other than the first sensor 211 and the second sensor 212 may be made longer than the first period of the output signal TS of the first sensor 211 and the second sensor 212.

[0074] <Second embodiment>

[0075] Figure 4 1 is a diagram showing an example of the first cycle, the second cycle, the third cycle, and the fourth cycle in the detection device 300 according to the second embodiment.

[0076] The second embodiment of the detection device 300 differs from the first embodiment of the detection device 200 in that the second sensor 212 outputs the second signal TS2 during the second period.

[0077] The second period, the third period, and the fourth period in the detection device 300 are the same and are set to be longer than the first period.

[0078] Thus, the diagnostic unit 140 of the second embodiment acquires the first signal TS1 in a first cycle and acquires the second signal TS2 in a second cycle that is longer than the first cycle. Furthermore, the diagnostic unit 140 diagnoses whether the first sensor 211 and the second sensor 212 are normal in the second cycle in which the first signal TS1 and the second signal TS2 are acquired.

[0079] As described above, in the detection device 300, the period of the first signal TS1 output by the first sensor 211 as an example of a part of the sensors among the first sensor 211 to the fourth sensor 214, that is, the first period, is shorter than the period (for example, the third period) of the signal TS output by the second sensor 212 to the fourth sensor 214 as an example of other sensors among the first sensor 211 to the fourth sensor 214.

[0080] According to the detection device 300 constructed as described above, the processing load of the control device 100 is reduced compared to a case where the first to fourth periods are all set to be the same as the first period, and the control device 100 diagnoses whether the first sensor 211 and the second sensor 212 are normal according to the first period and diagnoses whether the third sensor 213 and the fourth sensor 214 are normal.

[0081] Furthermore, in such a configuration, even if the first sensor 211 or the second sensor 212 fails, the operation of the electric motor 20 can be controlled using the third signal TS3 from the third sensor 213. Therefore, the above configuration does not reduce the safety of the steering system 1.

[0082] Furthermore, according to detection device 300, processing unit 110 uses first signal TS1 of first sensor 211, an example of a single sensor, and second signal TS2 of second sensor 212, an example of one of second to fourth sensors 212, 214, to diagnose whether first sensor 211 and second sensor 212 are functioning properly. Furthermore, if processing unit 110 diagnoses that first sensor 211 and second sensor 212 are functioning properly, it outputs first signal TS1 of first sensor 211 as torque signal Td, an example of a signal indicating the torque being detected. Therefore, according to detection device 300, the processing load on control device 100 can be reduced compared to detection device 200.

[0083] <Third embodiment>

[0084] Figure 5 This is a diagram showing an example of the amount of information transmitted by the first, second, third, and fourth cycles and the first, second, third, and fourth signals TS1, TS2, TS3, and TS4 in the detection device 400 according to the third embodiment.

[0085] Detection device 400 of the third embodiment differs from detection device 200 of the first embodiment in that the amount of information transmitted via first signal TS1, second signal TS2, third signal TS3, and fourth signal TS4 is different. The following primarily describes the differences between detection devices 200 and 400, omitting descriptions of similarities.

[0086] In detection apparatus 400, the amount of information transmitted by second signal TS2, third signal TS3, and fourth signal TS4 is less than the amount of information transmitted by first signal TS1. For example, if the amount of information transmitted by first signal TS1 is 16 bits, the amount of information transmitted by second signal TS2, third signal TS3, and fourth signal TS4 can be 15 bits or less.

[0087] When the amount of information sent through the second signal TS2, the third signal TS3 and the fourth signal TS4 is less than the amount of information sent through the first signal TS1, the amount of information parsed by the diagnostic unit 140 becomes less than the case where the amount of information sent through the first signal TS1 to the fourth signal TS4 is the same, and thus the processing load of the control device 100 is reduced.

[0088] Furthermore, the amount of information transmitted via the second signal TS2 is preferably selected to be a number of bits sufficient for diagnosing a malfunction of the first sensor 211 and the second sensor 212. Furthermore, the amount of information transmitted via the third signal TS3 and the fourth signal TS4 is preferably selected to be a number of bits sufficient for diagnosing a malfunction of the third sensor 213 and the fourth sensor 214.

[0089] In addition, it is desired to select the amount of information sent by the third signal TS3 and the fourth signal TS4 in such a manner that the third signal TS3 can be used to control the operation of the electric motor 20 so as not to affect normal steering even in an emergency such as when the first sensor 211 or the second sensor 212 fails.

[0090] Furthermore, in the third embodiment described above, the amount of information transmitted by the second signal TS2 is also less than the amount of information transmitted by the first signal TS1, but this is not particularly limiting. For example, the amount of information transmitted by the second signal TS2 may be the same as the amount of information transmitted by the first signal TS1. In this embodiment, compared to a case where the amount of information transmitted by the first to fourth signals TS1 to TS4 is the same, the amount of information analyzed by the diagnostic unit 140 is reduced, thereby reducing the processing load on the control device 100.

[0091] <Fourth embodiment>

[0092] Figure 6 This is a diagram showing an example of the amount of information transmitted by the first, second, third, and fourth cycles and the first, second, third, and fourth signals TS1, TS2, TS3, and TS4 in the detection device 500 according to the fourth embodiment.

[0093] Detection device 500 of the fourth embodiment differs from detection device 300 of the second embodiment in the amount of information transmitted via first signal TS1, second signal TS2, third signal TS3, and fourth signal TS4. The following primarily describes the differences between detection devices 300 and 500, omitting descriptions of similarities.

[0094] In detection apparatus 500, the amount of information transmitted by second signal TS2, third signal TS3, and fourth signal TS4 is less than the amount of information transmitted by first signal TS1. For example, if the amount of information transmitted by first signal TS1 is 16 bits, the amount of information transmitted by second signal TS2, third signal TS3, and fourth signal TS4 can be 12 bits.

[0095] When the amount of information sent through the second signal TS2, the third signal TS3 and the fourth signal TS4 is less than the amount of information sent through the first signal TS1, the amount of information parsed by the diagnostic unit 140 becomes less than the case where the amount of information sent through the first signal TS1 to the fourth signal TS4 is the same, and thus the processing load of the control device 100 is reduced.

[0096] Furthermore, the amount of information transmitted by the second signal TS2 is preferably selected to have a number of bits sufficient to diagnose a malfunction of the first sensor 211 and the second sensor 212. Furthermore, the amount of information transmitted by the third signal TS3 and the fourth signal TS4 is preferably selected to have a number of bits sufficient to diagnose a malfunction of the third sensor 213 and the fourth sensor 214.

[0097] In addition, it is desired to select the amount of information sent by the third signal TS3 and the fourth signal TS4 in such a manner that the third signal TS3 can be used to control the operation of the electric motor 20 even in an emergency such as when the first sensor 211 or the second sensor 212 fails so as not to affect normal steering.

[0098] Furthermore, in the fourth embodiment described above, the amount of information transmitted by the second signal TS2 is also less than the amount of information transmitted by the first signal TS1, but this is not particularly limiting. For example, the amount of information transmitted by the second signal TS2 may be the same as the amount of information transmitted by the first signal TS1. In this embodiment, compared to a case where the amount of information transmitted by the first to fourth signals TS1 to TS4 is the same, the amount of information analyzed by the diagnostic unit 140 is reduced, thereby reducing the processing load on the control device 100.

[0099] <Fifth embodiment>

[0100] Figure 7 This is a diagram showing an example of a schematic configuration of a detection device 600 according to the fifth embodiment.

[0101] Figure 8 This is a diagram showing an example of the amount of information transmitted through the first, second, third, and fourth cycles and the first, second, third, and fourth signals TS1, TS2, TS3, and TS4 in the detection device 600 according to the fifth embodiment.

[0102] Detection device 600 of the fifth embodiment differs from detection device 200 of the first embodiment in that first signal TS1 and second signal TS2 are transmitted via the same communication line 261, and third signal TS3 and fourth signal TS4 are transmitted via the same communication line 262. The following mainly describes the differences between detection device 200 and detection device 600, and omits descriptions of the similarities.

[0103] The detection device 600 includes a sensor unit 619 and a processing unit 510 corresponding to the processing unit 110 .

[0104] The sensor unit 619 includes a first sensor 611, a second sensor 612, a third sensor 613, and a fourth sensor 614. Hereinafter, when the first sensor 611, the second sensor 612, the third sensor 613, and the fourth sensor 614 do not need to be distinguished, they may be collectively referred to as sensors 610.

[0105] In the detection device 600, the first sensor 611 and the second sensor 612 sequentially transmit first and second signals TS1, TS2, as their respective detection signals, to the processing unit 510 via the communication line 261. More specifically, upon receiving a command signal from the processing unit 510, the first sensor 611 first transmits the first signal TS1 via the communication line 261, and then the second sensor 612 transmits the second signal TS2 via the communication line 261.

[0106] Furthermore, in the detection device 600, the third sensor 613 and the fourth sensor 614 sequentially transmit the third signal TS3 and the fourth signal TS4, which are their respective detection signals, to the processing unit 510 via the communication line 262. More specifically, upon receiving the command signal from the processing unit 510, the third sensor 613 first transmits the third signal TS3 via the communication line 262, and then the fourth sensor 614 transmits the fourth signal TS4 via the communication line 262.

[0107] Furthermore, in the detection device 600 of the fifth embodiment, the first period is the same as the second period, and the third period is the same as the fourth period, and the third period and the fourth period are set to be longer than the first and second periods. For example, the third and fourth periods can be integer multiples of the first and second periods. For example, if the first and second periods are 1 msec, the third and fourth periods can be 2 msec, 3 msec, 4 msec, or 5 msec.

[0108] The processing unit 510 includes a diagnosis unit 540 that diagnoses failures of the first sensor 611 , the second sensor 612 , the third sensor 613 , and the fourth sensor 614 , and a switching unit 560 .

[0109] After sequentially acquiring first and second signals TS1 and TS2 via communication line 261, diagnostic unit 540 diagnoses whether first and second sensors 611 and 612 are functioning properly. Furthermore, after sequentially acquiring third and fourth signals TS3 and TS4 via communication line 262, diagnostic unit 540 diagnoses whether third and fourth sensors 613 and 614 are functioning properly.

[0110] According to the detection device 600 constructed as described above, the processing load of the diagnosis unit 540 is reduced compared to a case where the first to fourth cycles are all set to be the same as the first cycle, and the diagnosis unit 540 diagnoses whether the first sensor 611 and the second sensor 612 are normal according to the first cycle and diagnoses whether the third sensor 613 and the fourth sensor 614 are normal.

[0111] Furthermore, in such a configuration, even if the first sensor 611 or the second sensor 612 fails, the operation of the electric motor 20 can be controlled using the third signal TS3 from the third sensor 613. Therefore, the above configuration does not reduce safety.

[0112] <Sixth embodiment>

[0113] Figure 9 This is a diagram showing an example of the amount of information transmitted by the first, second, third, and fourth cycles and the first, second, third, and fourth signals TS1, TS2, TS3, and TS4 in the detection device 700 according to the sixth embodiment.

[0114] Detection device 700 of the sixth embodiment differs from detection device 600 of the fifth embodiment in that the amount of information transmitted via first signal TS1, second signal TS2, third signal TS3, and fourth signal TS4 is different. The following primarily describes the differences between detection devices 600 and 700, omitting descriptions of similarities.

[0115] In the detection device 700, the amount of information transmitted by the third signal TS3 and the fourth signal TS4 is less than the amount of information transmitted by the first signal TS1 and the second signal TS2. For example, when the amount of information transmitted by the first signal TS1 and the second signal TS2 is 16 bits, the amount of information transmitted by the third signal TS3 and the fourth signal TS4 can be exemplified as 12 bits.

[0116] When the amount of information sent through the third signal TS3 and the fourth signal TS4 is less than the amount of information sent through the first signal TS1 and the second signal TS2, the amount of information parsed by the diagnosis unit 540 becomes less than the case where the amount of information sent through the first signal TS1 to the fourth signal TS4 is the same, and thus the processing load of the diagnosis unit 540 is reduced.

[0117] Furthermore, the amount of information transmitted through the third signal TS3 and the fourth signal TS4 is preferably selected to be a number of bits sufficient for diagnosing whether the third sensor 613 and the fourth sensor 614 are normal.

[0118] In addition, even in an emergency such as a failure of the first sensor 611 or the second sensor 612, it is preferable to select the amount of information sent by the third signal TS3 and the fourth signal TS4 in such a manner that the third signal TS3 can be used to control the operation of the electric motor 20 so as not to affect normal steering operations.

[0119] <Seventh embodiment>

[0120] Figure 10 This is a diagram showing an example of the amount of information transmitted by the first, second, third, and fourth cycles, the first signal TS1, the second signal TS2, the third signal TS3, and the fourth signal TS4 in the detection device 800 according to the seventh embodiment.

[0121] Detection device 800 of the seventh embodiment differs from detection device 200 of the first embodiment in that the second to fourth periods differ and the amount of information transmitted via first signal TS1, second signal TS2, third signal TS3, and fourth signal TS4 differs. The following primarily describes the differences between detection device 200 and detection device 800, omitting descriptions of similarities.

[0122] The second period, the third period, and the fourth period in the detection device 800 are set to be the same as the first period.

[0123] On the other hand, in detection apparatus 800, the amount of information transmitted by second signal TS2, third signal TS3, and fourth signal TS4 is less than the amount of information transmitted by first signal TS1. For example, if the amount of information transmitted by first signal TS1 is 16 bits, the amount of information transmitted by second signal TS2, third signal TS3, and fourth signal TS4 can be 12 bits.

[0124] As described above, in the detection device 800, the amount of information sent by the first signal TS1 of the first sensor 211, which is an example of a part of the sensors among the first sensor 211 to the fourth sensor 214, is greater than the amount of information sent by the signal TS of the second sensor 212 to the fourth sensor 214, which is an example of the other sensors among the first sensor 211 to the fourth sensor 214.

[0125] According to detection device 800, even if the first to fourth cycles are the same, if the amount of information transmitted via second signal TS2, third signal TS3, and fourth signal TS4 is less than the amount of information transmitted via first signal TS1, the amount of information analyzed by diagnosis unit 140 is less than when the amount of information transmitted via first signal TS1 to fourth signal TS4 is the same. As a result, the processing load on control device 100 is reduced.

[0126] Furthermore, the amount of information transmitted via the second signal TS2 is preferably selected to be a number of bits sufficient to diagnose whether the first sensor 211 and the second sensor 212 are functioning properly. Furthermore, the amount of information transmitted via the third signal TS3 and the fourth signal TS4 is preferably selected to be a number of bits sufficient to diagnose whether the third sensor 213 and the fourth sensor 214 are functioning properly.

[0127] In addition, it is desired to select the amount of information sent by the third signal TS3 and the fourth signal TS4 in such a manner that the third signal TS3 can be used to control the operation of the electric motor 20 so as not to affect normal steering even in an emergency such as when the first sensor 211 or the second sensor 212 fails.

[0128] Furthermore, in the seventh embodiment described above, the amount of information transmitted by the second signal TS2 is also less than the amount of information transmitted by the first signal TS1, but this is not particularly limiting. For example, the amount of information transmitted by the second signal TS2 may be the same as the amount of information transmitted by the first signal TS1. In this embodiment, compared to a case where the amount of information transmitted by the first to fourth signals TS1 to TS4 is the same, the amount of information analyzed by the diagnostic unit 140 is reduced, thereby reducing the processing load on the diagnostic unit 140.

[0129] Description of Reference Numerals

[0130] 1 ...electric power steering device, 100 ...control device, 110 ...processing unit, 140 ...diagnosing unit, 160 ...switching unit, 170 ...control unit, 200 ...detecting device, 211 ...first sensor, 212 ...second sensor, 213 ...third sensor, 214 ...fourth sensor.

Claims

1. A detection device comprising: a plurality of sensors that detect values ​​of detection objects; and a processing unit that processes the detection signals outputted from the plurality of sensors, The plurality of sensors are a first sensor, a second sensor, a third sensor, and a fourth sensor, The period for outputting the detection signals of the first sensor and the second sensor is shorter than the period for outputting the detection signals of the third sensor and the fourth sensor. The processing unit includes: a diagnosis unit that diagnoses failures of the first sensor, the second sensor, the third sensor, and the fourth sensor; and a switching unit that switches between using a first signal, which is a detection signal output from the first sensor, as the torque signal or using a third signal, which is a detection signal output from the third sensor, as the torque signal. The diagnostic unit uses the first signal and a second signal, which is a detection signal output from the second sensor, to diagnose whether the first sensor and the second sensor are normal or whether the first sensor or the second sensor has failed. The diagnostic unit uses the third signal and a fourth signal, which is a detection signal output from the fourth sensor, to diagnose whether the third sensor and the fourth sensor are normal or whether the third sensor or the fourth sensor has failed. When the diagnosis unit diagnoses that the first sensor and the second sensor are not faulty, the switching unit outputs the first signal as a torque signal. The switching unit outputs the third signal as a torque signal when the diagnosis unit diagnoses that the first sensor or the second sensor has failed and diagnoses that the third sensor and the fourth sensor have not failed.

2. A detection device comprising: a plurality of sensors that detect values ​​of detection objects; and a processing unit that processes the detection signals outputted from the plurality of sensors, The plurality of sensors are a first sensor, a second sensor, a third sensor, and a fourth sensor, The period of outputting the detection signals of the first sensor and the fourth sensor is shorter than the period of outputting the detection signals of the second sensor, the third sensor, and the fourth sensor. The processing unit includes: a diagnosis unit that diagnoses failures of the first sensor, the second sensor, the third sensor, and the fourth sensor; and a switching unit that switches between using a first signal, which is a detection signal output from the first sensor, as the torque signal or using a third signal, which is a detection signal output from the third sensor, as the torque signal. The diagnostic unit uses the first signal and a second signal, which is a detection signal output from the second sensor, to diagnose whether the first sensor and the second sensor are normal or whether the first sensor or the second sensor has failed. The diagnostic unit uses the third signal and a fourth signal, which is a detection signal output from the fourth sensor, to diagnose whether the third sensor and the fourth sensor are normal or whether the third sensor or the fourth sensor has failed. When the diagnosis unit diagnoses that the first sensor and the second sensor are not faulty, the switching unit outputs the first signal as a torque signal. The switching unit outputs the third signal as a torque signal when the diagnosis unit diagnoses that the first sensor or the second sensor has failed and diagnoses that the third sensor and the fourth sensor have not failed.

3. A steering device comprising: The detection device according to claim 1 or 2; and A control unit controls the operation of the electric motor using the value detected by the detection device.

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