sensor

Abstract

The present invention belongs to the field of sensor technology, and particularly relates to a sensor. The sensor is additionally provided with a wave generation monitoring module and a piezoelectric effect monitoring module and works in coordination with other components under the action of a controller. The sensor can further expand its detection performance while maintaining the advantages of sensor sensitivity and flexible installation, and can be used to detect the distance and contact pressure of objects, thereby expanding the application scenarios of the sensor.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a sensor. Background Art

[0002] Intelligent devices such as humanoid robots have complex structures and use highly integrated electronic and mechanical components. In order to achieve the robot's dexterous movements and complete complex tasks, it is necessary to equip it with small, flexible, and highly sensitive sensors. At present, sensors usually only have a single detection function. To achieve accurate positioning and perception of the action parts, it is necessary to deploy as many sensors as possible within the limited installation space of the action parts. This not only results in high application costs for sensors, but also makes it difficult to improve the performance of smaller action parts. Summary of the invention

[0003] The object of the present invention is to provide a sensor which can be used to detect the distance and contact pressure of an object.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is:

[0005] A sensor comprises a transducer element, an electric signal generating module, an electric signal receiving module, a wave generating monitoring module, a piezoelectric effect monitoring module and a controller;

[0006] The transducer element is used to receive the electric pulse output by the electric signal generating module and convert the electric pulse into an ultrasonic signal to be emitted outward;

[0007] The electric signal generating module is used for modulating the electric pulse and outputting it to the transducer element;

[0008] The electrical signal receiving module is used to receive the echo signal collected by the echo transducer element and output it to the controller after demodulation;

[0009] The wave emission monitoring module is used to monitor the amplitude of the transducer element when the transducer element emits an ultrasonic signal;

[0010] The piezoelectric effect monitoring module is used to collect voltage changes when the transducer element is subjected to mechanical pressure;

[0011] The controller is used to control the start and stop, and timing of the transducer element, electrical signal generating module, electrical signal receiving module, wave emission monitoring module, and piezoelectric effect monitoring module, collect the information uploaded by each component, analyze it, and output the detection results.

[0012] Compared with the prior art, the present invention has the following technical effects: the sensor is additionally provided with a wave generation monitoring module and a piezoelectric effect monitoring module and works in coordination with other components under the action of a controller. While maintaining the advantages of sensor sensitivity and flexible installation, the detection performance of the sensor can be further expanded to detect the distance and contact pressure of objects, thereby expanding the application scenarios of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following is a brief description of the contents and symbols in the drawings of this specification:

[0014] Figure 1 is a schematic diagram of the present invention;

[0015] Figure 2 It is a schematic diagram when the transducer elements are distributed in a 3×3 array;

[0016] Figure 3 It is a schematic diagram of the change in amplitude as the distance between the transducer element and the object gradually decreases. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described in detail below through description of embodiments in conjunction with the accompanying drawings.

[0018] As attached Figure 1 As shown, the sensor needs to be provided with at least a transducer element 10, an electric signal generating module 20, an electric signal receiving module 30, a wave generation monitoring module 40, a piezoelectric effect monitoring module 50 and a controller 60. Among them, the transducer element 10 needs to be made of a material having a piezoelectric effect. When the transducer element 10 is arranged at a distance from the object to be measured, the transducer element 10 first receives the electric pulse output by the electric signal generating module 20, and converts the electric pulse into an ultrasonic signal to be emitted outward, and then receives the ultrasonic echo signal and converts it into an electric pulse and transmits it to the electric signal receiving module 30; when the transducer element 10 contacts the object to be measured and the object to be measured applies a force to the transducer element 10, the transducer element 10 converts the mechanical force into an electric signal under the action of the piezoelectric effect and transmits it to the piezoelectric effect monitoring module 50.

[0019] The electric signal generating module 20 can modulate electric pulses and output them to the transducer element 10. The electric signal receiving module 30 can receive the echo signal collected by the echo transducer element 10 and output it to the controller 60 after demodulation. The wave emission monitoring module 40 can monitor the amplitude of the transducer element 10 when the transducer element 10 emits ultrasonic signals. The piezoelectric effect monitoring module 50 collects the voltage changes when the transducer element 10 is subjected to mechanical pressure. The controller 60 is used to control the start and stop and timing of the transducer element 10, the electric signal generating module 20, the electric signal receiving module 30, the wave emission monitoring module 40, and the piezoelectric effect monitoring module 50, and collects the information uploaded by each component and analyzes and outputs the detection results.

[0020] Details are as attached Figure 1As shown, one end of the transducer element 10 is grounded, and the other end is electrically connected to the electric signal generating module 20, the electric signal receiving module 30, the wave generation monitoring module 40, and the piezoelectric effect monitoring module 50. The controller 60 is electrically connected to the electric signal generating module 20, the electric signal receiving module 30, the wave generation monitoring module 40, and the piezoelectric effect monitoring module 50.

[0021] The control method of the sensor is that the controller 60 switches the working mode of the sensor according to the amplitude value of the wave when the transducer element 10 emits waves. In this embodiment, the sensor has an initial working mode, a distance measuring working mode, a contact sensing working mode and a pressure sensing working mode.

[0022] The controller 60 first compares the amplitude of the wave generated by the transducer element 10 with a preset value.

[0023] As attached Figure 3 As shown, when the amplitude value of the transducer element 10 emitting ultrasonic waves outward is within the preset amplitude value range of (-a, -b) ∪ (b, a), that is, when the measured wave amplitude value is consistent with the preset value, it can be determined that the transducer element 10 is emitting waves normally, and then the distance between the external object and the transducer element 10 can be detected normally, and the controller 60 switches to the distance measurement working mode.

[0024] In the ranging working mode, the transducer element 10 receives the electronic pulse wave output by the signal transmitting module 20 and converts it into ultrasonic wave to be emitted outward. After a preset time interval t, the signal receiving module 30 receives the echo signal collected by the transducer element 10. The controller 60 calculates the time difference between the transducer element 10 transmitting the ultrasonic wave and receiving the echo signal to obtain the distance between the adjacent object and the transducer element 10.

[0025] In a specific implementation, two or more transducer elements 10 may be arranged in an array on a flat or curved workpiece surface. Figure 2 The figure shows an embodiment of an array arrangement of 9 transducer elements. Each transducer element 10 is electrically connected to the same electric signal generating module 20 and electric signal receiving module 30 through a distribution circuit. When multiple transducer elements 10 are arranged on the outer surface of the device action part, by analyzing the relative position relationship of the transducer elements 10 and the collected echo signals, the approximate shape, size, spatial position of the object being measured, and the position relationship between the object and each transducer element 10 and other information can be obtained.

[0026] During the distance measurement process, the moving parts on which the transducer element 10 is installed or the object being measured may be displaced, thereby causing the distance between the transducer element 10 and the object being measured to change. Therefore, when the transducer element 10 emits ultrasonic waves outward, the wave emission monitoring module 40 needs to synchronously monitor the amplitude of the transducer element 10 so that the controller 60 can switch the working mode of the sensor in time according to the measured wave emission amplitude value.

[0027] When the transducer element 10 is arranged adjacent to or even partially in contact with the external object being measured, the amplitude of the wave generated by the transducer element 10 will be limited, which will further cause the amplitude of the wave generated by the transducer element 10 to be weakened or the wave waveform to oscillate and damp or even stop. Figure 3 As shown, if the amplitude value of the transducer element 10 when emitting ultrasonic waves outward is within the preset amplitude value range of (-b, b) and is not zero, it can be determined that the transducer element 10 is arranged adjacent to or even partially in contact with the object to be measured. At this time, the distance between the object to be measured and the transducer element 10 cannot be detected by echo, and the controller 60 switches to the contact sensing working mode.

[0028] In the contact sensing working mode, the transducer element 10 receives the electronic pulse wave output by the signal transmitting module 20 and converts it into ultrasonic wave to be emitted outward. At the same time, the wave emission monitoring module 40 monitors the amplitude of the transducer element 10 and the piezoelectric effect monitoring module 50 monitors the voltage of the transducer element 10.

[0029] After the transducer element 10 transmits waves outward for a preset time t, the signal receiving module 30 receives the echo signal collected by the transducer element 10. The controller 60 can obtain the time when the measured object and the transducer element 10 contact each other according to the time when the wave amplitude value changes, and can also obtain the duration of contact perception according to the time difference between the time when the wave amplitude value changes and the time when the wave amplitude value is zero, obtain the vibration-stopping contact force value according to the strain voltage value of the transducer element 10 when the wave amplitude value is zero, and obtain the tactile perception data of the contacted object according to the change rate of the wave amplitude value and the change rate of the strain voltage value.

[0030] Details are as attached Figure 3 As shown, slight contact or partial contact will not only affect the wave amplitude of the transducer element 10, but also cause the residual vibration amplitude to decay rapidly, and the number of residual vibration waves will also decrease sharply. The wave monitoring module 40 transmits the change of the waveform detection voltage at this time to the controller 60, and the controller 60 determines that the element has contacted the object based on this, so as to accurately define the moment when the contact occurs. The wave monitoring module 40 can adopt a common oscillation damping amplitude detection circuit, which is composed of a detection diode and an integration circuit. The detection circuit obtains the detection DC level after rectifying and integrating the amplitude of the oscillation waveform. The DC level after detection can reflect the changes in waveform, frequency and amplitude. The controller 60 continuously monitors the wave amplitude and the level after detection, and can also record the amplitude, period, number of pulses and waveform change characteristics of the oscillation main wave waveform at the current and damping time, and use it to analyze the contact perception performance of the object under test, such as elasticity and softness.

[0031] Since in the contact sensing working mode, the moving parts or the object to be measured on which the transducer element 10 is installed may be displaced, thereby causing the distance between the transducer element 10 and the object to be measured to change. Therefore, when the transducer element 10 emits ultrasonic waves outward, the controller 60 should also start the wave emission monitoring module 40 to synchronously monitor the amplitude of the transducer element 10, and start the piezoelectric effect monitoring module 50 to synchronously monitor the changes in the strain voltage value of the transducer element 10, so that the controller 60 can switch the working mode of the sensor in time according to the measured data.

[0032] In the contact sensing working mode, the wave generation monitoring module 40 and the piezoelectric effect monitoring module 50 respectively continuously monitor the changes in the amplitude and voltage of the transducer element 10 when it is working. Figure 3 As shown, when the amplitude value of the transducer element 10 emits ultrasonic waves and continues to decrease until it disappears, that is, the moment when the amplitude value of the transducer element 10 drops to 0, the controller 60 obtains the strain voltage value of the transducer element 10 measured by the piezoelectric effect monitoring module 50 at this moment to calculate the magnitude of the external force exerted on the transducer element 10. This force value can also be used to analyze and identify the tactile perception performance of the object being measured.

[0033] During the period from the moment when the amplitude of the transducer element 10 starts to change to the moment when the transducer element 10 stops vibrating, the wave emission monitoring module 40 continuously obtains the change information such as the amplitude of the wave emission of the transducer element 10, which can eliminate the possibility of false contact. At the same time, it can also monitor the contact process between the transducer element 10 and the object being measured and confirm whether the contact action is maintained, so that the controller 60 can perform data analysis and provide a basis for the control of the action component.

[0034] As attached Figure 3 As shown, when the measured wave amplitude value of the transducer element 10 is zero, the controller 60 switches to the pressure sensing working mode. In the pressure sensing working mode, the piezoelectric effect monitoring module 50 monitors the voltage of the transducer element 10, and the controller 60 calculates the magnitude of the external force applied to the transducer element 10 according to the change of the strain voltage value of the transducer element 10. The strain voltage value of the transducer element 10 is set to a preset value when the force applied by the external object to the transducer element 10 is less than the force value c. When the strain voltage value measured by the piezoelectric effect monitoring module 50 is consistent with the preset value, it is determined that the transducer element 10 is in close contact with the object to be measured, so the signal transmitting module 20 and the signal receiving module 30 stop working; when the external force value applied to the transducer element 10 is inconsistent with the preset value, it is determined that the contact state between the transducer element 10 and the object to be measured is unstable, and there is a risk of separation between the two, and the sensor 60 switches to the contact sensing working mode. Among them, the preset value should be greater than or equal to the force value measured by the piezoelectric effect monitoring module 50 when the amplitude value of the transducer element 10 drops to 0.

[0035] As attached Figure 3As shown, the horizontal axis is the distance between the measured object and the transducer element 10, and the vertical axis is the wave amplitude of the transducer element 10. When the sensor works normally, in the distance measurement working mode, the contact sensing working mode and the pressure sensing working mode, the distance between the measured object and the transducer element 10 gradually decreases. If the measured wave amplitude value is greater than the preset value, that is, when the wave monitoring module 40 measures that the absolute value of the wave amplitude of the transducer element 10 is greater than a, the wave amplitude value of the transducer element 10 is collected again. If the results of multiple collections all show that the absolute value of the wave amplitude of the transducer element 10 is greater than a, the sensor 60 outputs that the transducer element 10 is working abnormally.

[0036] Furthermore, in this embodiment, the sensor enters the initial working mode after being powered on. In the initial working mode, the transducer element 10 receives the electronic pulse wave output by the signal transmitting module 20 and converts it into ultrasonic wave to be emitted outwardly. At the same time, the wave emission monitoring module 40 monitors the amplitude of the transducer element 10 to obtain the wave emission amplitude value, and the controller 60 switches the working mode of the sensor according to the amplitude value of the wave emission of the transducer element 10.

Claims

1. A sensor, characterized in that: The sensor comprises a transducer element (10), an electric signal generating module (20), an electric signal receiving module (30), a wave generation monitoring module (40), a piezoelectric effect monitoring module (50) and a controller (60); The transducer element (10) is used to receive the electric pulse output by the electric signal generating module (20), and convert the electric pulse into an ultrasonic signal to be emitted outwardly; The electric signal generating module (20) is used to modulate the electric pulse and output it to the transducer element (10); The electrical signal receiving module (30) is used to receive the echo signal collected by the echo transducer element (10), demodulate the echo signal and output it to the controller (60); The wave emission monitoring module (40) is used to monitor the amplitude of the transducer element (10) when the transducer element (10) emits an ultrasonic signal; The piezoelectric effect monitoring module (50) is used to collect voltage changes when the transducer element (10) is subjected to mechanical pressure; The controller (60) is used to control the start and stop of the operation and the timing of the transducer element (10), the electric signal generating module (20), the electric signal receiving module (30), the wave generation monitoring module (40), and the piezoelectric effect monitoring module (50), collect information uploaded by each element, analyze it, and output the detection result.

2. The sensor according to claim 1, characterized in that: One end of the transducer element (10) is grounded, and the other end is electrically connected to the electric signal generating module (20), the electric signal receiving module (30), the wave generation monitoring module (40), and the piezoelectric effect monitoring module (50) respectively; The controller (60) is electrically connected to the electric signal generating module (20), the electric signal receiving module (30), the wave generation monitoring module (40), and the piezoelectric effect monitoring module (50) respectively.

3. The sensor according to claim 1, characterized in that: The wave generation monitoring module (40) is composed of a detection diode and a detection integration circuit.

4. The sensor according to claim 1, characterized in that: Two or more transducer elements (10) are arrayed on a flat or curved workpiece surface, and each transducer element (10) is electrically connected to the same electric signal generating module (20) and electric signal receiving module (30) via a distribution circuit.

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