Radar sensor device and robot system

Abstract

This laser sensor device is an FMCW laser sensor that detects the relative distance to an object and a relative speed with respect to the object for each frame. The laser sensor device: assesses, on the basis of the relative distance detected in a current frame and the relative distance detected in a previous frame, whether or not objects detected in each of the frames are the same object; assesses, on the basis of the relative speed detected in the current frame and the relative speed detected in the previous frame, whether or not the objects detected in each of the frames are the same object; and, if the objects are detected to be the same based on the relative distances but to not be the same based on the relative speeds, assesses that wrapping has occurred in the relative speed detected in the current frame.

Description

[Technical Field]

[0001] This specification discloses a radar sensor device and a robot system. [Background technology]

[0002] Conventionally, FMCW (Frequency Modulated Continuous Wave) radar sensor devices have been known as sensors that detect the relative distance to an object and the relative speed of the object. For example, Patent Document 1 discloses an FMCW radar sensor device that calculates multiple candidate values ​​of relative speed from the vehicle's speed, distance, and measurement value, sets an observation range according to the vehicle's speed by referring to a map of observation ranges for the vehicle's speed that has been created in advance, and selects, as the relative speed, a candidate value of the relative speed that falls within the set observation range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-207368 Summary of the Invention [Problem to be solved by the invention]

[0004] In an FMCW radar sensor device, the relative velocity between the sensor and an object is detected based on the phase difference between IF signals (a signal obtained by mixing transmitted chirps and received chirps) acquired from two points on a moving object using multiple transmitted chirps transmitted at regular intervals. However, if the phase difference between the IF signals exceeds 180°, aliasing of the relative velocity occurs, resulting in ambiguity in the relative velocity. The radar sensor device described in Patent Document 1 above requires a sensor to detect the vehicle speed in order to set an observation range according to the vehicle speed, which complicates the system. Similar problems can also occur when detecting the relative angle between the sensor and an object.

[0005] A primary object of the present disclosure is to appropriately determine the aliasing of a relative velocity or a relative angle with a simple configuration in an FMCW radar sensor device. [Means for solving the problem]

[0006] The present disclosure has adopted the following means to achieve the above-mentioned main object.

[0007] A first radar sensor device of the present disclosure includes: A radar sensor device of an FMCW type that detects a relative distance to an object and a relative speed between the object and the object for each frame, determining whether or not the objects detected in the current frame are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the objects detected in the current frame are the same object based on the relative velocity detected in the previous frame, and determining that aliasing has occurred in the relative velocity detected in the current frame when the objects are the same object based on the relative distance but not the same object based on the relative velocity; The gist of this is as follows.

[0008] In the first radar sensor device of the present disclosure, when it is determined that an object detected in the current frame and an object detected in the previous frame are the same object in terms of distance based on the relative distances to the object and the object detected in the current frame and the previous frame, but it is determined that the object and the object are not the same object in terms of speed based on the relative velocities of the object and the object detected in the current frame and the previous frame, it is determined that aliasing has occurred in the relative velocity. This makes it possible to appropriately determine whether aliasing has occurred in the relative velocity through simple processing.

[0009] A second radar sensor device of the present disclosure includes: A radar sensor device of an FMCW type that detects a relative distance to an object and a relative angle with respect to the object for each frame, determining whether or not the detected objects are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the detected objects are the same object based on the relative angle detected in the current frame and the relative angle detected in the previous frame, and determining that aliasing has occurred in the relative angle detected in the current frame when the detected objects are the same object based on the relative distance but not the same object based on the relative angle; The gist of this is as follows.

[0010] In the second radar sensor device of the present disclosure, when it is determined that an object detected in the current frame and an object detected in the previous frame are the same object in terms of distance based on the relative distance to the object, and when it is determined that the object detected in the current frame and the object detected in the previous frame are not the same object in terms of angle based on the relative angle between the object and the current frame, it is determined that aliasing has occurred in the relative angle. This makes it possible to appropriately determine whether aliasing has occurred in the relative angle through simple processing.

[0011] A first robot system of the present disclosure includes: a robot control device that controls the robot body; an FMCW radar sensor device that detects a relative distance to an object and a relative velocity between the object and the object for each frame, the radar sensor device determining whether or not the detected objects are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the detected objects are the same object based on the relative velocity detected in the current frame and the relative velocity detected in the previous frame, and determining that aliasing has occurred in the relative velocity detected in the current frame when the objects are the same object based on the relative distance but not the same object based on the relative velocity, and outputting a signal according to the determination result to the robot control device; The gist of the project is to provide the following:

[0012] The first robot system of the present disclosure includes the first radar sensor device of the present disclosure, and therefore can achieve the same effects as those achieved by the first radar sensor device.

[0013] A second robot system of the present disclosure includes: a robot control device that controls the robot body; Relative distance to an object and relative to the object angle and a radar sensor device of an FMCW type that detects the above for each frame, and determines whether or not the detected objects are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determines whether or not the detected objects are the same object based on the relative angle detected in the current frame and the relative angle detected in the previous frame, and when the detected objects are the same object based on the relative distance but not the same object based on the relative angle, determines that aliasing has occurred in the relative angle detected in the current frame, and outputs a signal according to the determination result to the robot control device. The gist of the project is to provide the following:

[0014] The second robot system of the present disclosure includes the second radar sensor device of the present disclosure, and therefore can achieve the same effects as those achieved by the second radar sensor device. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic configuration diagram of a robot system including a radar sensor device according to an embodiment of the present invention. [Figure 2] 10 is a flowchart illustrating an example of a folding determination process. [Figure 3] FIG. 10 is an explanatory diagram showing true values ​​and detected values ​​within and outside the detection range. [Figure 4] 10 is a flowchart illustrating an example of a folding determination process according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0017] FIG. 1 is a schematic configuration diagram of a robot system 1 including a radar sensor device 10 of this embodiment. As shown in FIG. 1, the robot system 1 includes a robot main body 2, a robot control device 3 that controls the operation of the robot main body 2, and a radar sensor device 10 that can detect objects (interfering objects) around the robot main body 2. The robot main body 2 may be a stationary robot or a self-propelled robot. Examples of the robot main body 2 include an arm robot equipped with a multi-joint arm that has a tool attached to its end to perform a predetermined task, and an automatic transport robot that travels along a predetermined travel route to transport items.

[0018] The radar sensor device 10 of this embodiment is a frequency modulated continuous wave (FMCW) radar sensor that can simultaneously detect the distance to an object and the relative distance from the object. If the robot body 2 is an arm robot, the radar sensor device 10 can be installed, for example, at the tip of the arm.

[0019] As shown in Figure 1, the radar sensor device 10 comprises a transmitting antenna unit 11 that transmits a transmitting chirp, a receiving antenna unit 12 that receives a wave reflected from an object as a receiving chirp, a synthesizer 13 that generates the transmitting chirp, a mixer 14 that mixes the transmitting chirp and the receiving chirp, a processing unit 20 that processes the output signal of the mixer 14 to detect the distance to the object and the relative velocity of the object, and a control unit 30 that controls the entire device.

[0020] The synthesizer 13 generates a transmit chirp signal whose frequency changes over time (for example, by linearly increasing the frequency). In this embodiment, the synthesizer 13 generates a set (one frame) of N transmit chirps (N is a natural number equal to or greater than 2) spaced apart by a fixed interval Tc.

[0021] The mixer 14 mixes the transmit chirp and the receive chirp to generate an intermediate frequency (IF) signal. The IF signal is composed of a tone with a fixed frequency. If there are multiple objects at different distances, the IF signal will contain tones with different frequencies for the waves reflected from each object. The instantaneous frequency of the IF signal is equal to the difference between the instantaneous frequencies of the transmit chirp and the receive chirp, and the phase of the IF signal is equal to the difference between the phases of the transmit chirp and the receive chirp.

[0022] The processing unit 20 includes an A / D converter (ADC) 21 that performs A / D conversion on the IF signal, and a DSP 22 that performs Fourier transform processing (FFT processing) on ​​the A / D converted IF signal to detect the relative distance to an object and the relative velocity of the object.

[0023] The DSP 22 includes a distance FFT unit and a velocity FFT unit. The distance FFT unit performs FFT processing (distance FFT processing) on ​​the IF signal on a chirp-by-chirp basis to obtain a frequency spectrum with a different peak for each tone. Each frequency peak indicates the presence of an object at a specific distance. Because the tone frequency and the relative distance to the object are proportional to each other, the relative distance to the object can be calculated based on the peak frequency. The velocity FFT unit performs further FFT processing (velocity FFT processing) on ​​the data after the distance FFT processing on a frame-by-frame basis to obtain angular frequency peaks. One set (one frame) of transmitted chirps is transmitted at a constant interval Tc, and the IF signals for each chirp obtained from an object that moves during that interval have different phases. The angular frequency corresponds to the phase difference between the IF signals of consecutive chirps. Since the angular frequency and the relative velocity of the object are proportional to each other, the relative velocity of the object can be calculated based on the peak angular frequency. However, since the relative velocity is detected based on the phase difference, aliasing occurs in the detected velocity if the phase difference is outside the range of -180° to +180°, resulting in ambiguity in the detected velocity. The radar sensor device 10 of this embodiment determines whether or not aliasing has occurred in the detected speed, and if it determines that aliasing has occurred, corrects the detected speed to eliminate ambiguity in the detected speed.

[0024] The control unit 30 is configured as a microprocessor centered around a CPU, and in addition to the CPU, is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, etc. Distance information and speed information are input to the control unit 30 for each frame from the processing unit 20 (DSP 22). The control unit 30 is also connected to the robot control device 3 so that it can communicate with the robot control device 3, and outputs data and signals to the robot control device 3.

[0025] Next, the operation of the radar sensor device 10 configured as above will be described. In particular, the operation of determining whether or not aliasing occurs in the detected speed obtained by the processing unit 20, and the operation of correcting the detected speed in accordance with the determination result will be described. Figure 2 is a flowchart showing an example of the aliasing determination process executed by the control unit 30 (CPU).

[0026] When the aliasing determination process is executed, the control unit 30 (CPU) first acquires the detection distance and detection speed of each object in the current frame from the processing unit 20 (S100). Next, the control unit 30 compares the detection distances detected in the previous frame (the frame immediately preceding the current frame) with those in the current frame (S110) and determines whether the two detection distances match within a first predetermined range (S120). Here, the first predetermined range is the error range within which the object detected in the previous frame and the object detected in the current frame can be considered to be objects at the same distance, i.e., the same object in terms of distance. The first predetermined range is predetermined to satisfy safety standards based on the specifications (distance resolution, etc.) of the radar sensor device 10. If the control unit 30 determines that the detection distances do not match within the first predetermined range, it determines that the two objects are different objects in terms of distance and terminates the aliasing determination process.

[0027] On the other hand, if the control unit 30 determines that the detected distances of both objects match within a first predetermined range, it determines that the two objects are the same object in terms of distance. Next, it compares the detected velocities detected in the previous frame and the current frame (S130) and determines whether the detected velocities of both objects match within a second predetermined range (S140). Here, the second predetermined range is an error range within which the object detected in the previous frame and the object detected in the current frame can be considered to have the same relative velocity, i.e., the same object in terms of velocity. The second predetermined range is predetermined to satisfy safety standards based on the specifications (velocity resolution, etc.) of the radar sensor device 10. If the control unit 30 determines that the detected velocities of both objects match within the second predetermined range, it determines that the two objects are the same object in terms of distance and velocity and that aliasing has not occurred in the detected velocity detected in the current frame. It then terminates the aliasing determination process without correcting the detected velocity.

[0028] On the other hand, if the control unit 30 determines that the detected velocities of both do not match within the second predetermined range, it determines that the object detected in the previous frame and the object detected in the current frame are the same object in terms of distance but different objects in terms of speed, and determines that aliasing has occurred in the detected speed (S150). Now, consider a case where the direction in which the object (target) approaches the radar sensor device 10 is defined as positive, and the relative speed of the target (object) is detected in a radar sensor device with a detection range of relative speed from -2.0 to +2.0 m / s. As shown in Fig. 3, when the target (object) is approaching at a speed of 2.0 m / s, the target's speed is within the detection range, and therefore the detected value obtained is a value that approximately matches the true value (2.0 m / s). On the other hand, if a target (object) is approaching at a speed of 2.4 m / s, the target's speed is outside the detection range, so velocity aliasing occurs at 2.0 m / s, and the detected value is a negative value of approximately -1.6 m / s (velocity moving away from the radar sensor device). Taking this into consideration, the control unit 30 determines that velocity aliasing has occurred when the objects detected in the previous frame and the current frame can be considered to be the same object in terms of distance but cannot be considered to be the same object in terms of velocity (when the detected velocity has changed beyond a normally considered extent). As described above, aliasing occurs when the phase difference of the IF signal between consecutive chirps falls outside the range of -180° to +180°, and the detection range of relative velocity is the velocity range corresponding to the phase difference range of -180° to +180°.

[0029] When the control unit 30 determines that aliasing has occurred in the velocity, it corrects the detected velocity of the current frame using the regularity of aliasing (S160). The correction of the detected velocity can be performed as follows. The result of the velocity FFT processing is expressed as N pieces of data corresponding to the number of data after the distance FFT processing (the number of transmission chirps in one frame), and the object is interpreted as having a velocity corresponding to the index (peak angular frequency) indicating the peak among the N pieces of data. Of the indexes with values ​​1 to N, the indexes with values ​​1 to (N / 2+1) are treated as representing velocities from 0 to the positive maximum value in the detection range, and the indexes with values ​​(N / 2+2) to N are treated as representing velocities from the negative maximum value to the negative minimum value in the detection range. In this case, the detected velocity V is obtained by the following equations (1) and (2), where Vres is the velocity resolution. When the velocity FFT processing results have a peak at the position (angular frequency) of value (N / 2+1), i.e., when the object further accelerates from a state where it has the maximum detectable positive velocity, a peak appears at the next index, value (N / 2+2). However, because this index is defined as the maximum negative value, the detected velocity V will not be the correct value. This is observed as aliasing. Aliasing correction is performed by calculating the detected velocity V using equation (1), which defines positive velocity, when a peak appears at an index defined for positive velocity in the previous frame and a peak appears at an index defined for negative velocity in the current frame for an object that is the same distance as the previous frame. Aliasing correction is also performed by calculating the detected velocity V using equation (2), which defines negative velocity, when a peak appears at an index defined for negative velocity in the previous frame and a peak appears at an index defined for positive velocity in the current frame for an object that is the same distance as the previous frame. For example, if a peak appears at the 17th index when N=32 in the previous frame, and a peak appears at the 18th index in the current frame, then normally, using equation (2), which defines a negative velocity, we would calculate (18-32)=-14×Vres. However, in this case, we use equation (1), which defines a positive velocity, and calculate 18×Vres.

[0030] V=k×Vres, where 1≦k≦N / 2+1 …(1) V = (kN) × Vres, where N / 2 + 2≦k≦N …(2)

[0031] After performing this aliasing correction, the control unit 30 compares the detection speed of the object detected in the previous frame with the corrected speed of the object detected in the current frame (S170) and determines whether the two speeds match within the second predetermined range (S180). If the control unit 30 determines that the two speeds match within the second predetermined range, it determines that the two can be considered to be the same object in terms of speed, sets (confirms) the corrected speed corrected in S160 as the detection speed of the object detected in the current frame (S190), and ends the aliasing determination process. On the other hand, if the control unit 30 determines that the two speeds do not match within the second predetermined range, it recognizes that the object detected in the previous frame and the object detected in the current frame are different objects moving at different relative speeds (S200), and ends the aliasing determination process without correcting the detection speed of the current frame.

[0032] It goes without saying that the present disclosure is not limited to the above-described embodiments, and can be embodied in various forms as long as they fall within the technical scope of the present disclosure.

[0033] For example, in the above-described embodiment, when the control unit 30 determines that aliasing has occurred in the detection speed of an object detected in the current frame, the control unit 30 corrects the detection speed of the current frame using the regularity of aliasing. However, when the control unit 30 determines that aliasing has occurred, the control unit 30 may set the detection speed of the current frame to the detection speed immediately before aliasing occurred (the detection speed of the previous frame). Alternatively, if the detection speed of the object up to the previous frame was a positive value (approaching the radar sensor device 10), the control unit 30 may set the detection speed of the current frame to the maximum positive value in the detection range, and if the detection speed of the object up to the previous frame was a negative value (moving away from the radar sensor device 10), the control unit 30 may set the detection speed of the current frame to the maximum negative value in the detection range.

[0034] In the above-described embodiment, the radar sensor 10 detects the relative distance to an object and the relative speed of the object. However, the radar sensor 10 may also detect the relative angle of the object (the angle of the object with respect to a reference direction from the radar sensor 10) and, if aliasing of the relative angle is determined, correct the relative angle based on the regularity of the aliasing. In this case, the radar sensor 10 may be configured as a MIMO (Multi-Input Multi-Output) radar sensor, for example, including a transmitting antenna unit 11 having multiple (X) transmitting antennas arranged in an array at a predetermined interval, and a receiving antenna unit 12 having multiple (Y) receiving antennas arranged in an array in the same direction as the transmitting antennas but at intervals different from the intervals of the transmitting antennas. By transmitting signals from the X transmitting antennas and receiving them simultaneously with the Y receiving antennas, the radar sensor can be considered to receive signals from X × Y virtual receiving antennas for one transmitting antenna, thereby achieving high angular resolution. The processing unit 20 performs FFT processing (angle FFT processing) on ​​the data after velocity FFT processing across multiple receiving antennas (X × Y virtual receiving antennas), and detects the time difference until the reflected waves from the object are received by each of the multiple receiving antennas as a phase difference (angular frequency), thereby calculating the relative angle to the object. However, because the relative angle is detected based on the phase difference, if the phase difference falls outside the range of -180° to +180°, aliasing occurs in the angle, similar to the detection of relative velocity, and the detected angle becomes ambiguous. The determination of aliasing of the relative angle and aliasing correction are performed by executing the flowchart in Figure 4. The aliasing determination process in Figure 4 will be described below.

[0035] When the aliasing determination process is executed, the control unit 30 (CPU) first acquires the detected distance and detected angle for each object in the current frame from the processing unit 20 (S300). Next, similar to S110 and S120 described above, the control unit 30 compares the detected distances in the previous frame and the current frame and determines whether the detected distances in both frames match within a first predetermined range (S310, S320). The first predetermined range was described above. If the control unit 30 determines that the detected distances in both frames do not match within the first predetermined range, it determines that the two objects are different objects in terms of distance, and ends the aliasing determination process.

[0036] On the other hand, if the control unit 30 determines that the detected distances of both objects match within the first predetermined range, it determines that the two objects are the same object in terms of distance. Next, it compares the detected angles detected in the previous frame and the current frame (S330) and determines whether the detected angles of both objects match within a third predetermined range (S340). Here, the third predetermined range is an error range within which the object detected in the previous frame and the object detected in the current frame can be considered to have the same relative angle, i.e., the same object in terms of angle. The third predetermined range is predetermined to satisfy safety standards based on the specifications (angular resolution, etc.) of the radar sensor device 10. If the control unit 30 determines that the detected angles of both objects match within the third predetermined range, it determines that the two objects are the same object in terms of distance and angle and that aliasing has not occurred in the detected angle detected in the current frame. It then terminates the aliasing determination process without correcting the detected angle.

[0037] On the other hand, if the control unit 30 determines that the detected angles of both frames do not match within the third predetermined range, it determines that the object detected in the previous frame and the object detected in the current frame are the same object in terms of distance but different objects in terms of angle, and determines that aliasing has occurred in the detected angle (S350). That is, the control unit 30 determines that aliasing has occurred in the angle when the objects detected in the previous frame and the current frame are the same object in terms of distance but cannot be considered the same object in terms of angle (when the detected angle has changed beyond a normally considered extent). Note that the determination of angle aliasing may be performed by adding the above-mentioned S130 and S140 between S320 and S330, and determining that aliasing has occurred in the detected angle when the detected distances in the previous frame and the current frame match within the first predetermined range, the detected speeds match within the second predetermined range, and the detected angles do not match within the third predetermined range.

[0038] When the control unit 30 determines that aliasing has occurred in the angle, it corrects the detected angle of the current frame using the regularity of aliasing (S360). The correction of the detected angle can be performed as follows. The result of the angle FFT processing is expressed as M pieces of data, and the object is interpreted as having an angle corresponding to the index (peak angular frequency) that indicates the peak among the M pieces of data. Of the indices 1 to M, the indices 1 to (M / 2+1) are treated as representing angles from 0 to the positive maximum value in the detection range, and the indices (N / 2+2) to N are treated as representing angles from the negative maximum value to the negative minimum value in the detection range. In this case, the detected angle θ is obtained by the following equations (3) and (4), where θres is the angular resolution. When the result of the angular FFT processing has a peak at the position (angular frequency) of value (M / 2+1), i.e., when the object moves further in the positive direction from the state where the angle is the maximum detectable positive angle, a peak appears at the next index, value (M / 2+2). However, because this index is defined as the maximum negative value, the detected angle θ will not be the correct value. This is observed as aliasing. Aliasing correction is performed by calculating the detected angle θ using Equation (3), which defines a positive angle, when a peak appears at an index defined as a positive angle in the previous frame and a peak appears at an index defined as a negative angle in the current frame for an object that is the same distance as the previous frame. Aliasing correction is also performed by calculating the detected angle θ using Equation (4), which defines a negative angle, when a peak appears at an index defined as a negative angle in the previous frame and a peak appears at an index defined as a positive angle in the current frame for an object that is the same distance as the previous frame. Here, in the radar sensor device 10, the phase difference Φ caused by the relative angle θ (detection angle) between the sensor and an object is expressed by the following equation (5). When the relative angle θ is sufficiently small, a linear approximation holds between the phase difference Φ and the relative angle θ, but as the relative angle θ increases, the relationship between the phase difference Φ and the relative angle θ becomes nonlinear. When the detection limit is exceeded, the relationship folds back in the nonlinear region.Considering this, the angular resolution θres in equations (3) and (4) may be determined not to be a constant but to gradually increase as k increases. In other words, different angular resolutions θres may be set for each angle bin, and equations (3) and (4) may be applied.

[0039] θ=k×θres, where 1≦k≦M / 2+1 …(3) θ=(kM)×θres, where M / 2+2≦k≦M …(4) Φ=πsinθ …(5)

[0040] After performing aliasing correction, the control unit 30 compares the detection angle of the object detected in the previous frame with the corrected angle of the object detected in the current frame (S370) and determines whether the two angles match within the third predetermined range (S380). If the control unit 30 determines that the two angles match within the third predetermined range, it determines that the two can be considered to be the same object in terms of angle, sets (confirms) the corrected angle corrected in S360 as the detection angle of the object detected in the current frame (S390), and ends the aliasing determination process. On the other hand, if the control unit 30 determines that the two angles do not match within the third predetermined range, it recognizes that the object detected in the previous frame and the object detected in the current frame are different objects located at different relative angles (S400), and ends the aliasing determination process without correcting the detection angle for the current frame.

[0041] As described above, in the first radar sensor device of the present disclosure, when it is determined that an object detected in the current frame and an object detected in the previous frame are the same object in terms of distance based on the relative distances to the object and the object detected in the current frame and the previous frame, but when it is determined that the object is not the same object in terms of speed based on the relative velocities of the object and the object detected in the current frame and the previous frame, it is determined that aliasing has occurred in the relative velocity. This makes it possible to appropriately determine whether aliasing has occurred in the relative velocity through simple processing.

[0042] In the first radar sensor device of the present disclosure, if it is determined that aliasing of the relative velocity has occurred in the current frame, the relative velocity detected in the current frame may be corrected using the regularity of the aliasing. This allows the detectable velocity range to be expanded through simple processing without increasing the sensing cycle or the amount of sensing data of the radar sensor device. In this case, if it is determined that aliasing of the relative velocity has occurred in the current frame, it may determine whether the objects detected in each frame are the same object based on a corrected velocity obtained by correcting the relative velocity detected in the current frame and the relative velocity detected in the previous frame. If it is determined that the objects are the same object, the corrected velocity may be set to the relative velocity detected in the current frame. If it is determined that the objects are not the same object, it may determine that the objects are different objects with different relative velocities. This allows for more appropriate correction of the relative velocity detected in the current frame. Furthermore, it is possible to prevent multiple different objects from being mistakenly recognized as the same object.

[0043] Furthermore, in the second radar sensor device of the present disclosure, when it is determined that an object detected in the current frame and an object detected in the previous frame are the same object in terms of distance based on the relative distances to the object, and when it is determined that the object detected in the current frame and the object detected in the previous frame are not the same object in terms of angle based on the relative angles between the object and the object, it is determined that aliasing has occurred in the relative angle. This makes it possible to appropriately determine whether aliasing has occurred in the relative angle through simple processing.

[0044] In the second radar sensor device of the present disclosure, if it is determined that aliasing of the relative angle has occurred in the current frame, the relative angle detected in the current frame may be corrected using the regularity of the aliasing. This allows the detectable angle range to be expanded through simple processing without increasing the sensing cycle or the amount of sensing data of the radar sensor device. In this case, if it is determined that aliasing of the relative angle has occurred in the current frame, it may determine whether the objects detected in each frame are the same object based on a corrected angle obtained by correcting the relative angle detected in the current frame and the relative angle detected in the previous frame. If it is determined that the objects are the same object, the corrected angle may be set to the relative angle detected in the current frame. If it is determined that the objects are not the same object, it may determine that the objects are different objects with different relative angles. This allows for more appropriate correction of the relative angle detected in the current frame. Furthermore, it is possible to prevent multiple different objects from being mistakenly recognized as the same object.

[0045] The present disclosure is not limited to the form of a radar sensor device, but may also be in the form of a robot system including a robot control device and a radar sensor device. [Industrial Applicability]

[0046] The present disclosure is applicable to industries such as the manufacturing of radar sensor devices and robots. [Explanation of symbols]

[0047] 1 robot system, 2 robot body, 3 robot control device, 10 radar sensor device, 11 transmitting antenna unit, 12 receiving antenna unit, 13 synthesizer, 14 mixer, 20 processing unit, 30 control unit.

Claims

1. An FMCW radar sensor device that detects a relative distance to an object and a relative speed between the object and the object for each frame, determining whether or not the objects detected in the current frame are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the objects detected in the current frame are the same object based on the relative velocity detected in the previous frame, and determining that aliasing has occurred in the relative velocity detected in the current frame when the objects are the same object based on the relative distance but not the same object based on the relative velocity; Radar sensor device.

2. The radar sensor device according to claim 1, If it is determined that aliasing of the relative velocity has occurred in the current frame, the relative velocity detected in the current frame is corrected using the regularity of aliasing. Radar sensor device.

3. 3. The radar sensor device according to claim 2, When it is determined that a return of the relative velocity has occurred in the current frame, it is determined whether or not the objects detected in each frame are the same object based on a corrected velocity obtained by correcting the relative velocity detected in the current frame and the relative velocity detected in the previous frame, and when it is determined that the objects are the same object, it sets the corrected velocity to the relative velocity detected in the current frame, and when it is determined that the objects are not the same object, it determines that the objects are different objects with different relative velocities. Radar sensor device.

4. An FMCW radar sensor device that detects a relative distance to an object and a relative angle with respect to the object for each frame, determining whether or not the detected objects are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the detected objects are the same object based on the relative angle detected in the current frame and the relative angle detected in the previous frame, and determining that aliasing has occurred in the relative angle detected in the current frame when the detected objects are the same object based on the relative distance but not the same object based on the relative angle; Radar sensor device.

5. The radar sensor device according to claim 4, If it is determined that aliasing of the relative angle has occurred in the current frame, the relative angle detected in the current frame is corrected using the regularity of aliasing. Radar sensor device.

6. 6. The radar sensor device according to claim 5, When it is determined that a relative angle wraparound has occurred in the current frame, it is determined whether or not the objects detected in each frame are the same object based on a corrected angle obtained by correcting the relative angle detected in the current frame and the relative angle detected in the previous frame, and when it is determined that the objects are the same object, it sets the corrected angle to the relative angle detected in the current frame, and when it is determined that the objects are not the same object, it determines that the objects are different objects with different relative angles. Radar sensor device.

7. a robot control device that controls the robot body; an FMCW radar sensor device that detects a relative distance to an object and a relative velocity between the object and the object for each frame, the radar sensor device determining whether or not the detected objects are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the detected objects are the same object based on the relative velocity detected in the current frame and the relative velocity detected in the previous frame, and determining that aliasing has occurred in the relative velocity detected in the current frame when the objects are the same object based on the relative distance but not the same object based on the relative velocity, and outputting a signal according to the determination result to the robot control device; A robot system comprising:

8. a robot control device that controls the robot body; an FMCW radar sensor device that detects a relative distance to an object and a relative angle to the object for each frame, the radar sensor device determining whether or not the detected objects are the same object based on the relative distance detected in the current frame and the relative distance detected in the previous frame, and determining whether or not the detected objects are the same object based on the relative angle detected in the current frame and the relative angle detected in the previous frame, and determining that aliasing has occurred in the relative angle detected in the current frame when the objects are the same object based on the relative distance but not the same object based on the relative angle, and outputting a signal according to the determination result to the robot control device; A robot system comprising:

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