阅读说明：本技术 用于检测车辆附近的地面不平坦的方法 (method for detecting ground unevenness in the vicinity of a vehicle ) 是由 埃格伯特·施皮格尔 于 2019-05-09 设计创作，主要内容包括：本发明涉及用于检测车辆附近的地面不平坦的方法及相关装置。该方法包括发射第一超声波脉冲(US1)或第一超声波突发脉冲并发射第二超声波脉冲(US2)或第二超声波突发脉冲,并且接收第一超声波脉冲(US1)或第一超声波突发脉冲的第一反射信号并接收第二超声波脉冲(US2)或者第二超声波突发脉冲的第二反射信号。在该方法的进一步过程中,比较第一反射信号和第二反射信号并且推断车辆附近的地面不平坦或者推断车辆附近的地面弯曲。(The present invention relates to a method and a related device for detecting ground unevenness in the vicinity of a vehicle. The method comprises transmitting a first ultrasonic pulse (US1) or a first ultrasonic burst and transmitting a second ultrasonic pulse (US2) or a second ultrasonic burst, and receiving a first reflected signal of the first ultrasonic pulse (US1) or the first ultrasonic burst and receiving a second reflected signal of the second ultrasonic pulse (US2) or the second ultrasonic burst. In a further course of the method, the first reflected signal and the second reflected signal are compared and an unevenness of the ground in the vicinity of the vehicle or a curvature of the ground in the vicinity of the vehicle is inferred.)

1. A method for detecting ground unevenness in the vicinity of a vehicle, comprising the steps of:

transmitting a first ultrasonic pulse (US1) or a first ultrasonic burst;

transmitting a second ultrasonic pulse (US2) or a second ultrasonic burst;

Receiving a first reflected signal of the first ultrasonic pulse (US1) or the first ultrasonic burst;

receiving a second reflected signal of the second ultrasonic pulse (US2) or the second ultrasonic burst;

Comparing the first and second reflected signals and inferring a surface irregularity in the vicinity of the vehicle or inferring a surface curvature in the vicinity of the vehicle.

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein the step of comparing the first and second reflected signals and inferring a ground unevenness or a ground curvature in the vicinity of the vehicle comprises the sub-steps of:

Performing a cross-correlation between a first period of the first reflected signal and a second period of the second reflected signal,

Wherein the cross-correlation can be performed prior to normalization of the first period of the first reflected signal and normalization of the second period of the second reflected signal, and

Wherein a cross-correlation signal is formed.

3. The method of claim 2, wherein the first and second light sources are selected from the group consisting of,

Wherein the step of comparing the first and second reflected signals and inferring that the ground in the vicinity of the vehicle is uneven comprises the sub-steps of:

Comparing the magnitude of the cross-correlation signal to a threshold;

Determining a time when the threshold is exceeded by the magnitude of the cross-correlation signal;

if the time is before the earliest allowed time or if the time is after the latest allowed time or if the threshold is not exceeded, it is concluded that the ground is uneven.

4. the method according to one or more of the preceding claims,

Wherein at least one of the reflected signals is multiplied with a gating signal prior to forming the cross-correlation.

5. the method according to one or more of claims 1 to 4,

Wherein the detected ground unevenness is a pothole, a stone, a parking lot boundary, a step, a stair-like terrain, or a platform.

6. a method for identifying ground unevenness in the vicinity of a vehicle, comprising the steps of:

transmitting a first ultrasonic pulse (US1) or a first ultrasonic burst;

Transmitting a second ultrasonic pulse (US2) or a second ultrasonic burst;

receiving the first ultrasonic pulse (US1) or a reflection of the first ultrasonic burst at a first time;

Receiving the second ultrasonic pulse (US2) or a reflection of the second ultrasonic burst at a second time;

comparing the first time with a first time window, the first time window starting and ending after the transmission of the first ultrasonic pulse (US1) or the first ultrasonic burst;

comparing the second time to a second time window, the second time window beginning and ending after transmitting the second ultrasonic pulse (US2) or the second ultrasonic burst;

Inferring a flat ground (B) if the first time is within the first time window and the second time is within the second time window;

The associated negative ground unevenness is inferred in the following cases:

If the first time is within the first time window and the second time is after an end time of the second time window, or if the second time cannot be determined, or

if the first time is after an end time of the first time window and the second time is after the end time of the second time window, or if the second time cannot be determined;

The relevant positive ground unevenness is inferred in the following cases:

If the first time is within the first time window and the second time is before the start time of the second time window, or

If the first time is before a start time of the first time window and the second time is before the start time of the second time window.

7. the method of claim 6, wherein the first and second light sources are selected from the group consisting of,

wherein the transmission of the first ultrasonic pulse (US1) or the first ultrasonic burst is carried out in the form of a first ultrasonic lobe, and

Wherein the transmission of the second ultrasonic pulse (US2) or the second ultrasonic burst takes place in the form of a second ultrasonic lobe, and

Wherein the first ultrasound lobe is oriented such that, in case of a flat ground (B), it meets the flat ground (B) over a first drop point (AP1) at a first distance (d1), and

Wherein the second ultrasound lobe is arranged such that, in case of a flat ground (B), the second ultrasound lobe meets the flat ground (B) at a second distance (d2) on a second drop point (AP2), and

wherein, in case of a flat ground, the first distance (d1) between the first landing point (AP) and the first ultrasonic sensor (S1) is smaller than the second distance (d2) between the second landing point (AP2) and the second ultrasonic sensor (S2).

8. The method according to claim 6 or 7,

wherein the detected ground unevenness is a pothole, a stone, a parking lot boundary, a step, a stair-like terrain, or a platform.

Technical Field

The present invention relates to a method and a related device for detecting ground unevenness in the vicinity of a vehicle.

background

Typically, it is necessary to park the vehicle on unpaved roads near ditches and other obstacles (e.g., kerbs or so-called curbs in parking lots, etc.). In this case, even if a rear-view camera is used, these obstacles cannot always be correctly detected and evaluated. This problem is exacerbated in the case of autonomous vehicles or unmanned robots. Unmanned vehicles should be prevented from driving into a ditch or down from, for example, single or multiple steps that may limit parking positions.

Disclosure of Invention

It is therefore an object of the present invention to provide a corresponding solution.

technical scheme of the invention

The method according to the invention for detecting a ground unevenness in the vicinity of a vehicle starts with the following steps: a first ultrasonic pulse (ultrashallpulses) or a first ultrasonic burst (ultrashallls-Bursts) in the form of a first ultrasonic lobe is emitted from the first ultrasonic sensor in the direction of the ground at a generally steep first angle, and a second ultrasonic pulse or a second ultrasonic burst in the form of a second ultrasonic lobe is emitted from the second ultrasonic sensor in the direction of the ground or almost horizontal at a more gradual second angle. Thus, the first ultrasonic lobe meets the ground at a first drop point at a first distance from the first ultrasonic sensor, and the second ultrasonic lobe meets the ground at a second drop point at a second distance from the second ultrasonic sensor, the first distance being shorter than the second distance. Preferably, the first ultrasonic sensor and the second ultrasonic sensor are arranged close to each other.

the first ultrasonic lobe is reflected at a first drop point on the ground and returns to the first ultrasonic sensor after traversing a first ultrasonic sensor-first drop point-first ultrasonic sensor path. The first ultrasonic sensor receives a reflection of the first ultrasonic pulse or a reflection of the first ultrasonic burst and converts the reflection into a first reflected signal.

the second ultrasonic lobe is reflected at a second drop point on the ground and returns to the second ultrasonic sensor after traversing a path of the second ultrasonic sensor-the second drop point-the second ultrasonic sensor. The second ultrasonic sensor receives a reflection of the second ultrasonic pulse or a reflection of the second ultrasonic burst and converts the reflection into a second reflected signal.

The analyzer then compares the first reflected signal and the second reflected signal and infers that the ground in the vicinity of the vehicle is uneven. Preferably, the analyzer signals such unevenness of the floor to the upper computer system.

In another embodiment, the method according to the invention is modified such that the step of comparing the first and second reflected signals and inferring the unevenness of the ground in the vicinity of the vehicle comprises the step of performing a cross-correlation between the first and second reflected signals. Typically, the normalization of the time periods of the first reflected signal and the normalization of the corresponding time periods of the second reflected signal are performed before the cross-correlation. However, this is not essential, but is suggested. In this case, the analyzer forms a cross-correlation signal between the predetermined time periods of the first and second reflected signals. The analyzer preferably compares the magnitude of the cross-correlation signal to a threshold and determines the time at which the threshold is exceeded by the magnitude of the cross-correlation signal. The time is a time required for the second ultrasonic signal of the second ultrasonic sensor to reach the ground longer than a time required for the first ultrasonic signal of the first ultrasonic sensor set to be steeper to reach the ground. Because the signal of the first ultrasonic sensor experiences a shorter distance than the signal of the second ultrasonic sensor, a delay of the second reflected signal relative to the first reflected signal is produced. This time difference is known when considering a flat ground as a reference. If the time difference is larger, the ground surface curves downward (i.e., sinks), and if the time difference is smaller, the ground surface near the vehicle curves upward. Thus, this method is also a method for determining the curvature of a surface in the vicinity of a vehicle. The analysis unit (analyzer) can infer that the ground is uneven if the time difference thus determined exceeds a predetermined level. These are in particular the following cases: the time determined by means of the correlation corresponding to such a time offset is either before the earliest permitted time for exceeding the threshold or after the latest permitted time or the threshold is not exceeded. Typically, reflections are expected to exist within a predetermined period of time after emission. It is therefore meaningful to multiply the reflected signal with the gating signal before forming the cross-correlation. In this case, the respective gating signal of the reflection signal is designed such that it is set to 1 in a time range in which reflection is expected and is set to 0 at other times. Typically, the ground unevenness detected is a pothole, a stone in front of the motor vehicle, a parking lot boundary, an ascending or descending step (Treppenstufen) or a stair-step terrain or platform (Podeste).

In another embodiment, a second equivalent method for detecting ground unevenness in the vicinity of a vehicle also starts with the following steps: a first ultrasonic pulse or ultrasonic burst is transmitted and a second ultrasonic pulse or ultrasonic burst is transmitted. Here, the reflection of the first ultrasonic pulse or the reflection of the first ultrasonic burst is also received at a first time and the reflection of the second ultrasonic pulse or the reflection of the second ultrasonic burst is received at a second time. Subsequently, the first time is compared to a first time window that starts and ends after the transmission of the first ultrasonic pulse or first ultrasonic burst, and the second time is compared to a second time window that starts and ends after the transmission of the second ultrasonic pulse or second ultrasonic burst. These time windows correspond to the gating signals described previously. Subsequently, the correlation of the time with the time window is evaluated. The analysis unit (analyzer) infers a flat ground if the first time is within the first time window and the second time is within the second time window. The analyzer infers a negative ground irregularity in relation if the first time is within the first time window and the second time is after an end time of the second time window or if the second time cannot be determined, or if the first time is after an end time of the first time window and the second time is after an end time of the second time window or if the second time cannot be determined. The analyzer infers an associated forward ground irregularity if the first time is within the first time window and the second time is before a start time of the second time window, or if the first time is before the start time of the first time window and the second time is before the start time of the second time window.

the transmission of the first ultrasonic pulse or first ultrasonic burst preferably takes place in the form of a first ultrasonic lobe, and the transmission of the second ultrasonic pulse or second ultrasonic burst preferably takes place in the form of a second ultrasonic lobe. In this case, the first ultrasound lobe is preferably oriented such that, in the case of a flat ground, the first ultrasound lobe meets the flat ground at a first distance at a first drop point. In this case, the second ultrasound lobe is preferably oriented such that, in the case of a flat ground, the second ultrasound lobe meets the flat ground at a second distance at a second drop point. In the case of a flat ground, the first distance between the first landing point and the sensor is generally smaller than the second distance between the second landing point and the sensor.

as mentioned above, the identified ground unevenness is a pothole, a stone, a parking lot boundary, an ascending or descending step and stair-like terrain, or a platform.

therefore, the device for detecting unevenness of the ground near the vehicle according to the present invention preferably includes a first ultrasonic sensor, a second ultrasonic sensor, and an analyzer for performing comparison. The first ultrasonic sensor is for emitting a first ultrasonic lobe and the second ultrasonic sensor is for emitting a second ultrasonic lobe. The first ultrasonic sensor receives a reflection of the first ultrasonic lobe. The second ultrasonic sensor receives a reflection of the second ultrasonic lobe. The first ultrasonic sensor converts the received reflection of the first ultrasonic lobe into a first reflected signal. The second ultrasonic sensor converts the received reflection of the second ultrasonic lobe into a second reflected signal. The first ultrasonic lobe is oriented such that, with flat ground, the first ultrasonic lobe meets the flat ground at a first distance at a first drop point. The second ultrasonic lobe is oriented such that, with flat ground, the second ultrasonic lobe meets the flat ground at a second distance at a second drop point. In the case of a flat ground, the first distance between the first landing point and the first ultrasonic sensor is preferably smaller than the second distance between the second landing point and the second ultrasonic sensor. The first ultrasonic sensor receives a reflection of the first ultrasonic lobe at a first time after transmission. The second ultrasonic sensor receives a reflection of the second ultrasonic lobe at a second time after transmission. The analyzer compares the first time to a first time window that begins and ends after the first ultrasonic lobe is transmitted. The analyzer compares the second time to a second time window that begins and ends after the second ultrasound lobe is transmitted. The analyzer preferably signals a flat ground if the first time is within the first time window and the second time is within the second time window. The analyzer preferably signals an associated negative ground irregularity if the first time is within a first time window and the second time is after an end time of a second time window or if the second time cannot be determined. The analyzer preferably signals a relevant negative ground irregularity if the first time is after the end time of the first time window and the second time is after the end time of the second time window or if the second time cannot be determined. If the first time is within the first time window and the second time is before the start time of the second time window, the analyzer preferably signals an associated forward ground unevenness. If the first time is before the start time of the first time window and the second time is before the start time of the second time window, the analyzer signals an associated forward ground irregularity.

the vehicle may be a non-autonomous vehicle or an autonomous vehicle. Autonomous vehicles may be manned or unmanned. For example, the vehicle may also be an automatically operated robot, such as a vacuum robot. For example, the ground unevenness may also be steps, stepped terrain, or small platforms.

In summary, the proposed device relates to a system for measuring the bending of a ground surface B in the vicinity of a vehicle by means of ultrasound and to a related method for measuring the bending of a ground surface B in the vicinity of a vehicle.

THE ADVANTAGES OF THE PRESENT INVENTION

For example, the invention enables navigation in such areas where no clear lane markings are present. For example, slipping into a road ditch can be prevented when navigating on an unpaved parking lot ground. It may also happen that the parking space is limited on one or more sides by the descending steps. Such a descending step can also be identified by the arrangement according to the invention and the method according to the invention.

drawings

FIG. 1 illustrates an exemplary rear portion of a motor vehicle.

fig. 2 schematically shows a reflected ultrasonic signal received by the ultrasonic sensor after reflection and reception.

Detailed Description

FIG. 1 illustrates an exemplary rear portion of a motor vehicle. The first ultrasonic sensor S1 transmits a first ultrasonic signal US1 to the ground B over a short distance d 1. The second ultrasonic sensor S2 transmits the second ultrasonic signal US2 to the ground B over the longer distance d 2. The first ultrasonic signal US1 meets the ground at a first drop point AP 1B. The second ultrasonic signal US2 meets the ground at a second drop point AP 2B. Since the second distance d2 is longer than the first distance d1, the first ultrasonic signal US1 requires less time for the distance from the first ultrasonic sensor S1 to the first landing point AP1 to the first ultrasonic sensor S1. In this case, the first ultrasonic sensor S1 receives a reflection of the first ultrasonic signal US1 at the first landing point AP1 from the ground B. In this case, the second ultrasonic sensor S2 also receives a reflection of the second ultrasonic signal US2 at the second landing point AP2 from the ground B.

Fig. 2 schematically shows reflected ultrasonic signals US1, US2 received by the ultrasonic sensors S1, S2 after reflection and reception. Fig. 2 a schematically shows a reflected received signal of the first ultrasonic sensor S1 with the first ultrasonic signal ES. Fig. 2 b schematically shows a reflected received signal of the second ultrasonic sensor S2 with the second ultrasonic signal FB. Here, the curve identified by FB represents the temporal position of the reflected pulse in the case of a flat ground B. The curve identified by AS schematically represents an exemplary temporal position of a reflected pulse in the case of a raised ground, a stone located in a road, a step located in a road, or a platform located in a road. The curve identified by AF represents an exemplary temporal position of the reflected pulse in the case of a sunken ground surface B or a depression or a trench located in the road or a down step in the road or down step-like terrain in the road. For the diagrams of a and b of fig. 2, the respective emission times of the respective ultrasonic signals US1, US2 are each identically selected as zero points and the same time scale is selected. The time delay between the curve ES of the received signal of the first ultrasonic sensor S1 with the reflection of the first ultrasonic signal and the curve FB for representing the time position of the reflected pulse in the case of a flat ground surface B represents a time reference value for determining whether the ground surface is sunken or raised. A first alarm may be triggered if the protrusion is greater than a predetermined protrusion threshold. A second alarm may be triggered if the subsidence is greater than a predetermined subsidence threshold.