Pressure detection method and pressure detection device with distance measurement protection

Abstract

The present invention discloses a pressure detection method with distance measurement protection, the method comprising: obtaining the distance between a moving body and a pressure subject in real time; obtaining the movement speed of the moving body when the distance reaches a preset distance; outputting a motion control instruction according to the movement speed and the preset distance to make the moving body contact the pressure subject at a preset speed; obtaining the pressure value between the pressure subject and the moving body. The present invention adjusts the impulse generated when the moving body hits the pressure subject by controlling the movement process of the moving body, so as to avoid the situation where the pressure sensor on the pressure subject is damaged by excessive impact force.

Description

Technical Field

[0001] The invention relates to the field of sensors, and in particular to a pressure detection method and a pressure detection device with ranging protection. Background Art

[0002] Many dynamic pressure measurement or weighing sites require contact between a moving body and a pressurized body in order to monitor the force and weight data. However, if the relative speed of the two is too fast, the pressure sensor set between them to detect the contact pressure between the two or the weight data of the moving body can easily be damaged by impact. Summary of the invention

[0003] The main purpose of the present invention is to propose a pressure detection method with distance measurement protection, aiming to solve the problem in the prior art that a pressure sensor installed on a pressure-bearing body is damaged by the impact of a moving body that moves too fast.

[0004] To achieve the above object, the present invention proposes a pressure detection method with ranging protection, the pressure detection method comprising:

[0005] Obtain the distance between the moving subject and the compressed subject in real time;

[0006] When the distance reaches a preset distance, obtaining the movement speed of the moving subject;

[0007] Outputting a motion control instruction according to the motion speed and the preset distance so as to make the moving body contact the pressured body at a preset speed;

[0008] The pressure value between the pressurized body and the moving body is obtained.

[0009] Preferably, the acceleration calculation formula for the moving subject to reach a preset speed within a preset distance is:

[0010]

[0011] Where a is the acceleration; ν 1 is the preset speed; ν0 is the moving speed of the moving subject when it reaches the preset distance; S is any distance value less than or equal to the preset distance.

[0012] Preferably, the pressure detection method further includes:

[0013] Comparing the pressure value between the pressure-bearing body and the moving body with a preset pressure value;

[0014] If the pressure value is greater than the preset pressure value, the preset speed is reduced accordingly;

[0015] If the pressure value is less than the preset pressure value, the preset speed is increased accordingly.

[0016] The present invention also proposes a pressure detection device with ranging protection, characterized in that it includes a ranging module, a pressure measuring module, a controller, a power supply module, a storage module and a communication module, and the ranging module, the pressure measuring module, the power supply module, the storage module and the communication module are all connected to the controller; the ranging module is used to detect the distance between the moving body and the pressure-bearing body, the pressure measuring module is used to collect the pressure data between the moving body and the pressure-bearing body, the storage module is used to store the distance and pressure data, the controller is connected to the host computer through the communication module, and the power supply module is used to provide power.

[0017] Preferably, the pressure measuring module includes a fixed base and a pressure-bearing surface installed on the pressure-bearing body, the pressure-bearing surface is located in the center of the fixed base and protrudes from the fixed base, and the ranging module includes a plurality of ranging probes, and the plurality of ranging probes are evenly arranged on the fixed base around the circumference of the pressure-bearing surface.

[0018] Preferably, the distance measuring module includes at least one of a laser distance measuring probe, an ultrasonic distance measuring probe and an infrared distance measuring probe.

[0019] Preferably, the pressure measuring module includes at least one of a strain gauge pressure sensor, a quartz pressure sensor, a vibrating wire pressure sensor, a ceramic pressure sensor and an electromagnetic pressure sensor.

[0020] Preferably, the communication module includes at least one of a wireless network communication module, an Ethernet interface, a wired serial port or a USB interface.

[0021] In the present invention, the pressure detection method aims to combine the motion control system of the moving body with the pressure sensor and the distance measuring sensor installed on the pressurized body (or the moving body), so as to achieve the pressure generated by the contact between the moving body and the pressurized body while adjusting the impact force generated when the moving body hits the pressurized body by controlling the motion process of the moving body, so as to avoid the situation where the pressure sensor on the pressurized body is damaged by excessive impact force. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of an embodiment of a pressure detection method with distance measurement protection of the present invention;

[0023] Figure 2 A diagram showing the relationship between the movement speed and time of a moving subject in an embodiment of a pressure detection method of the present invention;

[0024] Figure 3A diagram showing the relationship between the movement speed and time of a moving subject in another embodiment of the pressure detection method of the present invention;

[0025] Figure 4 It is a schematic diagram of the functional modules of the pressure detection device with distance measurement protection of the present invention;

[0026] Figure 5 It is a schematic diagram of the installation structure of the pressure measuring module and the distance measuring module in one embodiment of the pressure detection device of the present invention;

[0027] Figure 6 The figure is a schematic diagram of the installation structure of the pressure measuring module and the distance measuring module in another embodiment of the pressure detection device of the present invention. DETAILED DESCRIPTION

[0028] The embodiments of the present invention will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same reference numerals throughout represent the same elements or elements with the same functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but cannot be understood as limiting the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0029] In order to solve the above technical problems, the present invention proposes a pressure detection method with distance measurement protection, which aims to combine the motion control system of the moving subject with the pressure sensor and the distance measurement sensor installed on the pressure-receiving subject (or the moving subject) to achieve the pressure generated by the contact between the moving subject and the pressure-receiving subject, and adjust the impact force generated when the moving subject hits the pressure-receiving subject by controlling the motion process of the moving subject, so as to avoid the situation where the pressure sensor on the pressure-receiving subject is damaged by excessive impact force. The pressure detection method includes:

[0030] Step S10: Acquire the distance between the moving body and the pressured body in real time.

[0031] In this step, the moving body is the force-applying object, and the pressure-receiving body has a pressure-receiving surface arranged toward the moving body, which is used to bear the pressure generated by the moving body after contacting it to achieve the purpose of production and processing. A pressure sensor is arranged on the pressure-receiving surface to collect the pressure of the moving body and the pressure-receiving body in contact, and a distance sensor is also arranged on the pressure-receiving surface to collect the distance between the moving body and the pressure-receiving body in real time. The pressure sensor and the distance sensor can also be installed on the side of the moving body facing the pressure-receiving body.

[0032] Step S20: When the distance reaches a preset distance, the movement speed of the moving subject is obtained.

[0033] In this step, the distance between the moving body and the pressure body is shortened as the moving body approaches the pressure body. The moving speed of the moving body can be obtained by a speed sensor (such as a Hall speed sensor) provided in the driving motor of the moving body, or by a linear speed sensor, or by a distance measuring sensor collecting the distance between the moving body and the pressure body at multiple time points, and calculating the distance by combining the physical relationship formed by the known motion acceleration and the time difference between multiple time points. When the distance between the moving body and the pressure body reaches the preset distance, that is, the distance between the moving body and the pressure body is the preset distance ( Figure 2 or Figure 3 At the time point t1 in the figure, the moving speed of the moving subject when it reaches the position is obtained. The preset distance can be determined according to actual production requirements.

[0034] Step S30: outputting a motion control instruction according to the motion speed and the preset distance, so as to make the moving body contact the pressure body at a preset speed.

[0035] The purpose of this step is to accurately control the movement speed of the moving body when it contacts the pressure body, to prevent the impact force of the moving body on the pressure body from damaging the pressure sensor, and the control of the movement speed of the moving body is equivalent to making the pressure between the two objects accurately controllable. In most applications, such as film laminating machines, manipulators, electric cylinders, hydraulic cylinders, cylinders, and pressure tests, when the moving body is close to contacting the pressure body, its movement speed needs to be controlled within a very small range, so the preset speed described in this step can be set to be very small, such as 1mm / s, to reduce the impact force of the pressure body to almost zero, so as to better control the pressure acting on the workpiece to ensure the operation accuracy. In some instruments, the moving body is required to hit the pressure body with a relatively large impulse, such as a pile driver, a forging machine, a punching machine, etc., and a large impact force is used to achieve the processing purposes of punching and bending of articles.

[0036] The motion control system outputs a motion control instruction for the next motion speed of the motion subject according to the motion speed of the motion subject acquired in the previous step and the distance between the motion subject and the pressure subject (i.e., the preset distance). The motion control instruction is received by the driving motor of the motion subject, and the driving motor of the motion subject starts to decelerate accordingly until the speed drops to the preset speed, such as Figure 2In the time period t1-t2 shown in , the movement speed v0 drops to v1 (preset speed). In this process, the moving body decelerates at a certain acceleration, and the process of reaching the contact with the pressurized body takes less time than directly changing to the preset speed at a preset distance from the pressurized body. In addition, the purpose of setting the preset distance is to give the moving body a certain buffer distance to avoid damage to related components such as the drive motor caused by a sudden change in output power. When the moving body is outside the preset distance, it can run at a higher speed. When it enters the preset distance, it starts to decelerate in time, which reduces the time spent on the movement of the moving body, improves production efficiency, and protects the pressure sensor at the same time.

[0037] Step S40: obtaining the pressure value between the pressurized body and the moving body.

[0038] By controlling the relative speed between the pressure-bearing body and the moving body within a certain range, damage to the pressure sensor can be avoided. Therefore, the pressure sensor can accurately detect the pressure value between the pressure-bearing body and the moving body, and the pressure value can be uploaded to the host computer for processing.

[0039] In a preferred embodiment, in step 30, the acceleration calculation formula for the moving subject to reach a preset speed within a preset distance is:

[0040]

[0041] Wherein, a is the acceleration; ν1 is the preset speed; ν0 is the movement speed when the distance between the moving body and the pressure body reaches the preset distance; S is any distance value less than or equal to the preset distance.

[0042] In this embodiment, S is the deceleration distance of the moving body, which can be set according to demand. The larger S is, the shorter the total time it takes for the moving body to reach the pressured body from time point t1.

[0043] The deceleration distance S of the moving body can be set to be equal to the preset distance, that is, when the moving speed of the moving body is reduced to the preset distance, it just contacts the pressed body. Figure 2 As shown in , the speed starts to slow down at time t1, and at time t2 the speed is reduced to a preset speed and hits the compressed object (at this time S is equal to the preset distance); or the distance S is set to a value less than the preset distance, that is, when the moving speed of the moving subject is reduced to the preset distance, it has not yet reached the compressed body, and then moves forward at the preset distance until it contacts the compressed body, as shown in Figure 3As shown in the figure, the speed starts to slow down at time t1, and the speed is reduced to the preset speed at time t2 (S is the travel distance of the moving body from t1 to t2), and it hits the compressed body at time t3. Compared with the two settings of the speed reduction distance S of the moving body, the former is more efficient, and the latter is relatively safer, which can be selected according to actual needs.

[0044] In a preferred embodiment, it also includes:

[0045] Comparing the pressure value between the pressure-bearing body and the moving body with a preset pressure value;

[0046] If the pressure value is greater than the preset pressure value, the preset speed is reduced accordingly;

[0047] If the pressure value is less than the preset pressure value, the preset speed is increased accordingly.

[0048] The pressure value between the pressure subject and the moving subject collected by the pressure sensor is affected by the relative speed when the two subjects are in contact. The purpose of this embodiment is to obtain the physical relationship between the two, so as to achieve accurate control of the pressure between the pressure subject and the moving subject and improve the processing accuracy. Among them, the preset pressure value is the ideal pressure value obtained by the system based on multiple practices. When the pressure between the pressure subject and the moving subject is the preset pressure value, the processing effect is the best. In addition to the conventional controllable influencing factors such as the relative force between the two, the pressure between the pressure subject and the moving subject measured by the pressure sensor is also affected by the impact force, that is, the product of the mass of the moving subject and the relative speed is related to the quotient of the deformation (buffer) time during contact. Therefore, the pressure between the two can be controlled by controlling the relative speed between the pressure subject and the moving subject. Conversely, the actual effect of the preset speed can be obtained according to the actual pressure value between the moving subject and the pressure subject fed back by the pressure sensor, forming a closed-loop control loop so that the actual pressure value is as close to the preset pressure value as possible to achieve the best processing effect.

[0049] The present invention also provides a pressure detection device with distance measurement protection, such as Figure 4 As shown, the pressure detection device includes a distance measuring module 1, a pressure measuring module 2, a controller 3, a power module 4, a storage module 5 and a communication module 6. The distance measuring module 1, the pressure measuring module 2, the power module 4, the storage module 5 and the communication module 6 are all connected to the controller 3. The distance measuring module 1 is used to detect the distance between the moving body and the pressure-bearing body. The pressure measuring module 2 is used to collect the pressure data between the moving body and the pressure-bearing body. The storage module 5 is used to store the distance and pressure data. The controller 3 is connected to the host computer through the communication module 6, and the power module 4 is used to provide power.

[0050] The present invention is applied to the above-mentioned pressure detection method with distance measurement protection. The distance measurement module 1 is used to detect the distance between the moving body and the pressure-bearing body, the pressure measurement module 2 is used to detect the pressure data between the moving body and the pressure-bearing body, and the control module is used to send the distance and pressure data to the host computer through the communication module 6 to control the movement of the moving body. The communication module 6 adopts a standard communication bus interface and can form a communication network with the host computer. The communication module 6 can adopt wireless communication, such as Bluetooth, WIFI, or connect to the host computer through a cable. The storage module 5 is used to store the above-mentioned distance and pressure data. The power supply module 4 can be connected to an external DC power supply to ensure that the pressure detection device acts as an autonomous working node. At the same time, the power supply module 4 also includes a backup power supply, which is realized by a lithium nickel battery charge and discharge management circuit to ensure that the pressure detection device can work in an uninterruptible power supply mode.

[0051] Preferably, the controller 3 may adopt the STM32F107RCT6 model. The controller 3 accesses each group of sensors in turn via the bus and obtains the data measured by each sensor, thereby simplifying the number of I / O ports consumed by connecting multiple sensor modules (ranging module 1 and pressure measuring module 2, especially when the ranging module 1 and the pressure measuring module 2 each include multiple sensor probes) to the controller 3.

[0052] This embodiment integrates the distance measuring module 1 and the pressure measuring module 2, the controller 3, the communication module 6, the power supply module 4 and other components into a complete sensor. Combined with the steps of the above-mentioned pressure detection method with distance measuring protection, the movement speed of the moving body is controlled by prior distance measurement to solve the problem of a large impact force between the moving body and the pressure-bearing body, which may damage the pressure detection device.

[0053] In a preferred embodiment, if Figure 5 and Figure 6 As shown, the pressure measuring module 2 includes a fixed base 21 and a pressure bearing surface 22 installed on the pressure-bearing body, the pressure bearing surface 22 is located in the center of the fixed base 21 and protrudes from the fixed base 21, and the ranging module 1 includes a plurality of ranging probes, and the plurality of ranging probes are evenly arranged on the fixed base 21 around the circumference of the pressure bearing surface 22.

[0054] In this embodiment, the pressure-bearing body has a pressure-bearing surface facing the moving body, and the fixed base 21 of the pressure measuring module 2 is installed on the pressure-bearing surface. The pressure-bearing surface 22 of the pressure measuring module 2 is arranged in the center of the fixed base 21 and protrudes from the side of the fixed base 21 facing the moving body, so as to generate a pressure signal under pressure. The distance measuring module 1 includes a plurality of distance measuring probes, which are arranged on the fixed base 21 around the circumference of the pressure bearing surface 22, and the detection direction thereof is toward the moving body. The distance measuring probe and the pressure bearing surface 22 are not on the same plane and have a certain height difference, so that the distance measuring probe can be prevented from being pressed by the moving body.

[0055] The controller 3 controls the multiple distance measuring probes to collect data in groups and in time, and sends the collected distances to the control module for analog-to-digital conversion and then uploads them to the host computer for processing through the communication module 6. The multiple distance measuring probes are symmetrically arranged left and right, front and back, and the plane wavefront detection characteristics of the data in the spatially symmetrical structure can assist the host computer in reconstructing the distance and movement speed between the entire pressure-applying surface of the moving subject and the pressure-receiving subject.

[0056] In a preferred embodiment, the distance measuring module 1 includes at least one of a laser distance measuring probe, an ultrasonic distance measuring probe and an infrared distance measuring probe.

[0057] In this embodiment, the selection of the ranging module 1 needs to be based on actual needs, such as the accuracy and viewing angle range required by the application environment, and one of them can be selected; it can also include the above-mentioned several ranging probes at the same time, and when in use, open one of them according to actual needs, such as Figure 6 As shown, the distance measuring module 1 includes a laser distance measuring probe 11 and an ultrasonic distance measuring probe 12 (or other combinations, Figure 6 This is just an example to illustrate how to arrange multiple distance measuring probes. The two types of probes are symmetrically arranged around the pressure bearing surface 22 of the pressure measuring module 2 without interfering with each other.

[0058] In a preferred embodiment, the pressure measuring module 2 includes at least one of a strain gauge pressure sensor, a quartz pressure sensor, a vibrating wire pressure sensor, a ceramic pressure sensor and an electromagnetic pressure sensor.

[0059] In this embodiment, the pressure measuring module 2 may be selected from one of the gas according to actual needs; it may also include the above-mentioned several distance measuring probes at the same time, and when in use, open a suitable one according to actual needs.

[0060] In a preferred embodiment, the communication module 6 includes at least one of a wireless network communication module 61, an Ethernet interface 62, a wired serial port or a USB interface.

[0061] The function of the communication module 6 is to upload the pressure data and distance data to the host computer, and transmit the control instructions issued by the host computer to the control module. The communication module 6 includes a wireless network SOC (i.e., a wireless network communication module 61) and / or an Ethernet interface 63, which communicates with the host computer through a built-in antenna and an RJ45 network port respectively. The communication module 6 does not need to be connected to a data cable, and only requires other working nodes (host computers) to support commonly used communication protocols (modbus, TCP / IP, UDP) to access the data of the pressure detection device. It can be used as an independent network node device to access the entire motion control system; the wired serial port or USB interface is used as an interface that requires a cable connection, and can be used as a backup when the network is not accessible.

[0062] The above are only partial or preferred embodiments of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A pressure detection method with ranging protection, characterized in that: include: Obtain the distance between the moving subject and the compressed subject in real time; When the distance reaches a preset distance, obtaining the movement speed of the moving subject; Outputting a motion control instruction according to the motion speed and the preset distance so as to make the moving body contact the pressured body at a preset speed; Acquiring a pressure value between the pressure-bearing body and the moving body; The acceleration calculation formula for the moving subject to reach a preset speed within a preset distance is: Wherein, a is acceleration; v1 is the preset speed; v0 is the movement speed of the moving subject when it reaches the preset distance; S is any distance value less than or equal to the preset distance; The detection method further comprises: Comparing the pressure value between the pressure-bearing body and the moving body with a preset pressure value; If the pressure value is greater than the preset pressure value, the preset speed is reduced accordingly; If the pressure value is less than the preset pressure value, the preset speed is increased accordingly.

2. A pressure detection device with ranging protection, characterized in that: It includes a distance measuring module, a pressure measuring module, a controller, a power supply module, a storage module and a communication module, wherein the distance measuring module, the pressure measuring module, the power supply module, the storage module and the communication module are all connected to the controller; the distance measuring module is used to detect the distance between the moving body and the pressure-bearing body, and when the distance reaches a preset distance, the movement speed of the moving body is obtained; the pressure measuring module is used to obtain the pressure value between the pressure-bearing body and the moving body, and the storage module is used to store the distance and the pressure value; the controller is connected to the upper computer through the communication module, and is used to output a motion control instruction according to the movement speed and the preset distance, so as to make the moving body contact the pressure-bearing body at a preset speed; the power supply module is used to provide power; The distance measurement module calculates the acceleration of the moving body to reach a preset speed within a preset distance according to the following formula: Wherein, a is acceleration; v1 is the preset speed; v0 is the movement speed of the moving subject when it reaches the preset distance; S is any distance value less than or equal to the preset distance; The controller is also used for: Comparing the pressure value between the pressure-bearing body and the moving body with a preset pressure value; If the pressure value is greater than the preset pressure value, the preset speed is reduced accordingly; If the pressure value is less than the preset pressure value, the preset speed is increased accordingly.

3. The pressure detection device with ranging protection according to claim 2, characterized in that: The pressure measuring module includes a fixed base and a pressure bearing surface installed on the pressure-bearing body, the pressure bearing surface is located in the center of the fixed base and protrudes from the fixed base, and the ranging module includes a plurality of ranging probes, and the plurality of ranging probes are evenly arranged on the fixed base around the circumference of the pressure bearing surface.

4. The pressure detection device with distance measurement protection according to claim 2, characterized in that: The distance measuring module includes at least one of a laser distance measuring probe, an ultrasonic distance measuring probe and an infrared distance measuring probe.

5. The pressure detection device with distance measurement protection according to claim 2, characterized in that: The pressure measuring module includes at least one of a strain gauge pressure sensor, a quartz pressure sensor, a vibrating wire pressure sensor, a ceramic pressure sensor and an electromagnetic pressure sensor.

6. The pressure detection device with distance measurement protection according to claim 2, characterized in that: The communication module includes at least one of a wireless network communication module, an Ethernet interface, a wired serial port or a USB interface.

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