JP7745010B2 - Radar sensor device and robot system - Google Patents

Description

This specification discloses a radar sensor device and a robot system.

Conventionally, FMCW (Frequency Modulated Continuous Wave) radar sensor devices have been known as sensors for detecting 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 for relative speed from the vehicle's speed, distance, and measurement values, sets an observation range corresponding to the vehicle's speed by referencing a pre-created map of observation ranges for the vehicle's speed, and selects, as the relative speed, a candidate value for relative speed that falls within the set observation range.

Japanese Patent Application Laid-Open No. 2017-207368

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 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, mentioned above, requires a sensor to detect the vehicle's speed in order to set an observation range according to the vehicle's speed, complicating the system. Similar problems can also occur when detecting the relative angle between the sensor and an object.

The main purpose of this disclosure is to appropriately determine the aliasing of relative velocity or relative angle using a simple configuration in an FMCW radar sensor device.

This disclosure takes the following measures to achieve the above-mentioned main objective.

A first radar sensor device of the present disclosure includes:
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;
The gist of this is as follows.

In the first radar sensor device disclosed herein, if it is determined that an object detected in the current frame and the previous frame is the same object in terms of distance based on the relative distance to the object, but it is determined that the object is not the same object in terms of speed based on the relative speed to the object detected in the current frame and the previous frame, it is determined that aliasing has occurred in the relative speed. This allows for appropriate determination of aliasing in the relative speed using simple processing.

A second radar sensor device of the present disclosure includes:
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;
The gist of this is as follows.

In the second radar sensor device disclosed herein, if it is determined that the objects detected in the current frame and the previous frame are the same in terms of distance based on the relative distance to the object, but it is determined that the objects are not the same in terms of angle based on the relative angle between the object and the current frame and the previous frame, it is determined that aliasing has occurred in the relative angle. This allows for appropriate determination of aliasing in the relative angle using simple processing.

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:

The first robot system disclosed herein is equipped with the first radar sensor device disclosed herein, and can therefore achieve effects similar to those achieved by the first radar sensor device.

A second 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 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;
The gist of the project is to provide the following:

The second robot system disclosed herein is equipped with the second radar sensor device disclosed herein, and can therefore achieve effects similar to those achieved by the second radar sensor device.

1 is a schematic configuration diagram of a robot system including a radar sensor device according to an embodiment of the present invention. 10 is a flowchart illustrating an example of a folding determination process. FIG. 10 is an explanatory diagram showing true values and detected values within and outside the detection range. 10 is a flowchart illustrating an example of a folding determination process according to another embodiment.

Next, the form for implementing this disclosure will be described with reference to the drawings.

Figure 1 is a schematic diagram of a robot system 1 including a radar sensor device 10 of this embodiment. As shown in Figure 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.

The radar sensor device 10 of this embodiment is an FMCW (Frequency Modulated Continuous Wave) radar sensor that can simultaneously detect the distance to an object and the relative distance to the object. If the robot main body 2 is an arm robot, the radar sensor device 10 can be installed, for example, at the tip of the arm.

As shown in Figure 1, the radar sensor device 10 comprises a transmitting antenna section 11 that transmits a transmitting chirp, a receiving antenna section 12 that receives a reflected wave 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 section 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 section 30 that controls the entire device.

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 greater than or equal to 2) spaced at a fixed interval Tc.

The mixer 14 mixes the transmit chirp and receive chirp to generate an intermediate frequency (IF) signal. The IF signal consists 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 phase of the transmit chirp and the phase of the receive chirp.

The processing unit 20 includes an A/D converter (ADC) 21 that performs A/D conversion of 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.

The DSP 22 has a distance FFT section and a velocity FFT section. The distance FFT section 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, the relative distance to the object can be calculated based on the peak frequency. The velocity FFT section 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. A set (one frame) of transmitted chirps is transmitted at a constant interval Tc, and the IF signals for each chirp obtained from an object moving during that interval have different phases. The angular frequency corresponds to the phase difference of the IF signals between consecutive chirps. Because the angular frequency and the relative velocity of the object are proportional, the relative velocity of the object can be calculated based on the peak angular frequency. However, because relative velocity is detected based on the phase difference, if the phase difference is outside the range of −180° to +180°, aliasing occurs in the detected velocity, resulting in ambiguity in the detected velocity. The radar sensor device 10 of this embodiment determines whether aliasing has occurred in the detected velocity, and if it determines that aliasing has occurred, corrects the detected velocity to eliminate ambiguity in the detected velocity.

The control unit 30 is configured as a microprocessor centered around a CPU, and in addition to the CPU, it also has 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 it, and outputs data and signals to the robot control device 3.

Next, we will explain the operation of the radar sensor device 10 configured in this manner. In particular, we will explain the operation of determining whether or not aliasing has occurred in the detected speed obtained by the processing unit 20, and the operation of correcting the detected speed in accordance with the determination result. Figure 2 is a flowchart showing an example of the aliasing determination process executed by the control unit 30 (CPU).

When the aliasing determination process is executed, the control unit 30 (CPU) first obtains the detection distance and detection speed for 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 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.

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. It then compares the detected velocities in the previous and current frames (S130) and determines whether the detected velocities of both objects match within a second predetermined range (S140). Here, the second 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 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.

On the other hand, if the control unit 30 determines that the detected velocities of both objects 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 considered to be the same object in terms of distance but are different objects in terms of speed, and determines that a wraparound has occurred in the detected speed (S150). Now, consider the case where the direction in which the object (target) approaches the radar sensor device 10 is positive, and the relative speed detection range is -2.0 to +2.0 m/s, and the relative speed of the target (object) is detected using a radar sensor device. As shown in Figure 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 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, resulting in a negative detected 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 and current frames can be considered the same object in terms of distance but cannot be considered the same object in terms of velocity (when the detected velocity has changed beyond a normally considered level). 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 for relative velocity is a velocity range corresponding to the phase difference range of -180° to +180°.

When the control unit 30 determines that aliasing has occurred in the velocity, it corrects the detected velocity for the current frame using the regularity of the aliasing (S160). Correction of the detected velocity can be performed as follows. The results of the velocity FFT processing are expressed as N pieces of data corresponding to the number of data points after the distance FFT processing (the number of transmitted chirps in one frame), and the object is interpreted as having a velocity corresponding to the index (peak angular frequency) that indicates the peak among the N pieces of data. Among the indices ranging from 1 to N, the indices from 1 to (N/2+1) represent velocities from 0 to the positive maximum value in the detection range, while the indices from (N/2+2) to N represent velocities from the negative maximum value to the negative minimum value in the detection range. In this case, the detected velocity V, where Vres is the velocity resolution, is calculated using the following equations (1) and (2): When the result of the velocity FFT processing has a peak at a position (angular frequency) of value (N/2+1), i.e., when the object further accelerates from a state where the object 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, the result would be (18-32)=-14×Vres. However, in this case, using equation (1), which keeps the definition of a positive velocity, the result is 18×Vres.

V = k × Vres, where 1 ≤ k ≤ N/2 + 1 ... (1)
V = (kN) × Vres, where N/2 + 2≦k≦N … (2)

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 terminates 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 terminates the aliasing determination process without correcting the detection speed for the current frame.

It goes without saying that the present disclosure is in no way limited to the above-described embodiments, and can be implemented in various forms as long as they fall within the technical scope of the present disclosure.

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, it corrects the detection speed of the current frame using the regularity of aliasing. However, when the control unit 30 determines that aliasing has occurred, it may also 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.

In the above-described embodiment, the radar sensor device 10 detects the relative distance to an object and the relative velocity of the object. However, it may also detect the relative angle of the object (the angle of the object relative to a reference direction from the radar sensor device 10). If the relative angle is determined to be aliased, the relative angle may be corrected based on the regularity of the aliasing. In this case, the radar sensor device 10 may be configured as a MIMO (Multi-Input Multi-Output) radar sensor, for example, with the transmitting antenna unit 11 including multiple (X) transmitting antennas arranged in an array at a predetermined interval, and the receiving antenna unit 12 including multiple (Y) receiving antennas arranged in an array in the same direction as the transmitting antennas but at intervals different from the spacing of the transmitting antennas. By transmitting signals from the X transmitting antennas and receiving them simultaneously with the Y receiving antennas, the radar sensor device can be considered to receive signals from X x Y virtual receiving antennas for one transmitting antenna, 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 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 with respect 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 of FIG. 4. The aliasing determination process of FIG. 4 will be described below.

When the folding determination process is executed, the control unit 30 (CPU) first obtains 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 distance-wise different objects and terminates the folding determination process.

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. It then compares the detected angles 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 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 with the same relative angle, i.e., the same object angularly. 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 no aliasing has occurred in the detected angle detected in the current frame. It then terminates the aliasing determination process without correcting the detected angle.

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

When the control unit 30 determines that aliasing has occurred in the angle, it corrects the detected angle for the current frame using the regularity of the aliasing (S360). Correction of the detected angle can be performed as follows. The results of the angle FFT processing are 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 ranging from 1 to M, the indices from 1 to (M/2 + 1) are treated as representing angles from 0 to the positive maximum value in the detection range, and the indices from (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, where θres is the angular resolution, is obtained using the following equations (3) and (4): When the result of the angular FFT processing has a peak at a position (angular frequency) of value (M/2+1), i.e., when the object moves further in the positive direction from a state where the object has 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. 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 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 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, aliasing is performed by calculating the detected angle θ using equation (4), which defines a negative angle. 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. However, as the relative angle θ increases, the relationship between the phase difference Φ and the relative angle θ becomes nonlinear. Furthermore, once the detection limit is exceeded, aliasing occurs in the nonlinear region. Taking this into consideration, the angular resolution θres in equations (3) and (4) may not be a constant, but may be determined to gradually increase as k increases. In other words, a different angular resolution θres may be set for each angle bin, and equations (3) and (4) may be applied.

θ=k×θres, where 1≦k≦M/2+1 ... (3)
θ=(kM)×θres, where M/2+2≦k≦M … (4)
Φ = π sin θ ... (5)

After performing aliasing correction, the control unit 30 compares the detected 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 angularly, sets (confirms) the corrected angle corrected in S360 as the detected angle of the object detected in the current frame (S390), and terminates 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 terminates the aliasing determination process without correcting the detected angle for the current frame.

As described above, the first radar sensor device of the present disclosure determines that aliasing has occurred in the relative velocity when it determines that the objects detected in the current frame and the previous frame are the same object in terms of distance based on the relative distances to the objects, but determines that the objects are not the same object in terms of speed based on the relative velocities of the objects detected in the current frame and the previous frame. This allows for appropriate determination of aliasing in the relative velocity using simple processing.

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. It also prevents multiple different objects from being mistakenly recognized as the same object.

In addition, the second radar sensor device of the present disclosure determines that aliasing has occurred in the relative angle when it determines that the objects detected in the current frame and the previous frame are the same object in terms of distance based on the relative distance to the object, but determines that the objects are not the same object in terms of angle based on the relative angle between the object and the current frame and the previous frame. This allows for appropriate determination of aliasing in the relative angle through simple processing.

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 range of detectable angles to be expanded through simple processing without increasing the sensing cycle or 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 the 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. It may also be possible to prevent multiple different objects from being mistakenly recognized as the same object.

This disclosure is not limited to the form of a radar sensor device, but can also be in the form of a robot system equipped with a robot control device and a radar sensor device.

This disclosure can be used in industries such as radar sensor device and robot manufacturing.

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 (8)

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. 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. 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. 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. 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. 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. 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: 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: