Soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force, and method for converting data in the sensor into a signal

Abstract

The invention relates to a soft spring-shaped sensor with variable pitch spring and magnetic connections, capable of measuring compression force; the magnetic connections enable connection to robots or human-machine interfaces in different configurations more easily without the need for an additional connection element and the variable spring pitch feature provides more linear and magnitude-wise continuous data acquisition compared to sensors with different connection types and fixed spring pitch sizes.

Description

[0001] SOFT SPRING-SHAPED SENSOR WITH VARIABLE SPRING PITCH AND MAGNETIC CONNECTIONS, CAPABLE OF MEASURING COMPRESSION FORCE, AND METHOD FOR CONVERTING DATA IN THE SENSOR INTO A SIGNAL

[0002] Technical Field of the Invention

[0003] The invention relates to a soft spring-shaped sensor with variable pitch spring and magnetic connections, capable of measuring compression force; the magnetic connections enable connection to robots or human-machine interfaces in different configurations more easily without the need for an additional connection element and the variable spring step feature provides more linear and magnitude-wise continuous data acquisition compared to sensors with different connection types and fixed spring step sizes.

[0004] State of the Art

[0005] The working principle of soft sensors is similar to basic strain gauges. Under mechanical operation or deformation, the resistance of the soft sensor decreases. This resistance change is proportional to the applied force and the deformation experienced by the sensor. This resistance change can be converted into a voltage change using a quarter Wheatstone bridge.

[0006] Currently, there are sensors available on the market for force measurement and deformation amount measurement, but these sensors have a rigid structure. There are miniature sensors that can be used as strain gauges. Although they are paper-shaped and flexible, since they do not have a three-dimensional shape, they are placed on surfaces and deformation measurements are made.

[0007] The invention, which is the subject of the application numbered “CN109176589” in the state of the art, describes a soft mechanical arm based on SMA springs. The soft mechanical arm consists of a platform. A plurality of mechanical arm fingers are placed under the platform. Each mechanical arm finger consists of a silica gel outer shell. Each silica gel outer shell is internally equipped with a soft sensor and two corresponding SMA springs. The invention, which is the subject of the application numbered “CN101065721 B” in the state of the art, relates to a magnetic sensor for detecting movement and / or position, a module containing such a sensor, and a computer input device comprising a pressure sensor, a microphone, an accelerometer and such a magnetic sensor. This sensor device can be used to detect not only the static position of the magnetically conductive element but also the changes in its static position.

[0008] The production of soft sensors in the state of the art requires a sensitive production and is costly. Considering the necessary sensitive production and cost, the sensors developed by the invention in the form of a soft spring provide an alternative solution for force measurement and compression amount measurement in many areas. In many sectors, a sensor that can be used as a practical and cost-effective force sensor or deformation amount measurement sensor is needed. In this way, it can be used in the automotive sector for passive measurement of spring stiffness and effective forces on the spring in active suspension systems. It can also be a basic measurement component for formable human-machine interfaces and wearable robots.

[0009] The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force, that enables connection to robots or humanmachine interfaces in different configurations more easily without the need for an additional connection element and provides a variable spring pitch feature that provides more linear and continuous data acquisition from sensors compared to the magnetic connection type and fixed spring pitch feature is not seen in the state of the art.

[0010] As a result, due to the negativities described above and the inadequacy of existing solutions on the subject, it has become necessary to make a development in the relevant technical field.

[0011] Brief Description and Aims of the Invention

[0012] The invention relates to a soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force, that enables connection to robots or human-machine interfaces in different configurations more easily without the need for an additional connection element and provides a variable spring pitch feature that provides more linear and continuous data acquisition from sensors compared to the magnetic connection type and fixed spring pitch feature.

[0013] The most important aim of the invention is to enable it to be used as a practical and cost-effective force sensor or deformation amount measurement sensor.

[0014] Another aim of the invention is to enable the sensors to be easily produced from a three-dimensional printer. The spring pitch in the sensor design can be changed and feedback can be provided to the systems for many applications. Easy production also provides serious conveniences for mass production and prototyping processes.

[0015] Another aim of the invention is that due to the high range and high linearity of the sensor, no data processing or machine learning methods are needed when utilizing these sensors for environmental perception on robots. The lack of data processing allows the system to save computing power. In this way, sensors can provide real-time and uninterrupted data flow through robots, automation systems, and human-machine interaction interfaces.

[0016] Description of Drawings

[0017] Figure -1 is the drawing showing the image of the sensor that is the subject of the invention.

[0018] Reference Numbers

[0019] 1) Upper permanent magnet

[0020] 2) Variable pitch spring

[0021] 3) Lower permanent magnet a) Spring pitch b) Spring pitch c) Spring pitch Description of the Invention pitchpitch The invention relates to a soft spring-shaped sensor with variable pitch spring and magnetic connections, capable of measuring compression force; the magnetic connections enable connection to robots or human-machine interfaces in different configurations more easily without the need for an additional connection element and the variable spring pitch feature provides more linear and magnitude-wise continuous data acquisition compared to sensors with different connection types and fixed spring pitch sizes.

[0022] The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force consists of at least one upper permanent magnet (1 ), at least one lower permanent magnet (3) and a variable pitch spring (2) provided between said upper (1 ) and lower permanent magnet (3).

[0023] In the invention, said variable pitch spring (2) is obtained by three-dimensional printing with conductive thermoplastic polyurethane material. Said variable pitch spring (2) is fixed in a tight fit by placing it between the supplied upper permanent magnet (1 ) and the lower permanent magnet (3). In this way, the variable pitch spring (2) is ensured to be in constant contact with the upper permanent magnet (1 ) and the lower permanent magnet (3) and therefore to be conductive. In addition, the variable pitch spring (2) has a spring geometry with the length of the spring pitches (a, b, c) linearly increased (acbcc). By means of said linearly increased spring pitch length, the coils come into contact with each other in order under compression, resulting in a controlled and significant (60-80%) reduction in resistance. This linear change between the spring pitches can be adjusted during design according to the amount of resolution expected from the sensor. In the invention, the conversion of digital data into a signal happens as follows:

[0024] - Conversion of the resistance change that occurs during compression into a voltage change with the help of a Wheatstone bridge,

[0025] - Sending analogue data to the microprocessor with the help of an amplifier, and

[0026] - Conversion of analogue data into a digital signal by the microprocessor. In this way, sensor data can be used in different applications as feedback of compression force and quantity.

[0027] The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force comprises the features of magnetic connection type and variable pitch spring. The magnetic connection type sensors allow for easier connection to robots or human-machine interfaces with different configurations without the need for an additional connection element. The variable spring pitch feature allows for more linear and continuous data to be obtained from the sensors compared to the fixed spring pitch feature used previously. In sensors using fixed spring pitch feature, it is not possible to obtain compression or force data from the sensor without all spring coils touching each other, whereas in variable spring pitch feature, there is no such requirement since the coils touch each other in order under compression. In other words, in this newly developed variable pitch spring (2), linearity is achieved in the sensor output against compression by increasing the spring pitchs (a, b, c) linearly, and as a result of the coils touching each other in order under compression, a controlled and significant decrease in resistance is provided. When no force is applied to spring type sensors, their electrical resistances measured are high, and when force is applied, their electrical resistances are low because the spring is compressed. High resistance can be 2.5 - 5 times the low resistance, in other words, when force is applied, the sensor resistance decreases by 60% - 80%.

[0028] By means of the magnetic type connection, the sensors can be shaped according to the user's wishes for robots or interfaces. This situation provides users with great ease of use and flexibility for the use of the sensor. Said sensor can be used in various areas such as wearable technology and rehabilitation due to its flexible structure. Said sensor can be easily integrated and removed from designed interfaces or other smart systems by means of the magnetic repulsion / attraction feature of said upper permanent magnet (1 ) and lower permanent magnet (3).

[0029] Said sensor can be produced on a three-dimensional printer. The spring pitch in the sensor design can be changed and feedback can be provided to the systems for many applications. The ease of production also provides serious conveniences for mass production. Using a flexible conductive material gives the sensor a soft structure, making it promising for wearable robot systems or human-machine interaction interfaces. Said soft spring-shaped sensor that can measure the compression force and amount has the potential to be used as force feedback for haptic and tactile perceptions. In the preferred embodiment of the invention, conductive thermoplastic polyurethane, a flexible material, is used.

[0030] In addition, various data processing and machine learning methods are used to increase the reliability of the data obtained from the soft sensors available in the literature. However, by means of this unique sensor, there is no need to use any data processing or machine learning methods while using the sensors to increase environmental perception on robots. This saves the system's computing power. For this reason, the sensors can provide real-time and uninterrupted data flow through the robots, automation systems and human-machine interaction interfaces where they are used.

Claims

CLAIMS1. A soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force, comprising:- at least one upper permanent magnet (1 ) and at least one lower permanent magnet (3) that allow magnetic connection type connection to the devices without the need for a connecting element, and- a variable pitch spring (2) positioned between the upper permanent magnet (1 ) and the lower permanent magnet (3), the pitchs of which can be increased and decreased regularly.

2. Method to convert data to signal in spring-shaped sensor, comprising the process steps of:- Conversion of the resistance change that occurs during compression into a voltage change with the help of a Wheatstone bridge,- Sending analogue data to the microprocessor with the help of an amplifier, and- Conversion of analogue data into a digital signal by the microprocessor.

3. The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force according to Claim 1 , wherein the variable pitch spring (2) is made of conductive thermoplastic polyurethane material.

4. The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force according to Claim 1 , comprising the variable pitch spring (2) that is placed between the upper permanent magnet (1 ) and the lower permanent magnet (3) to ensure a tight fit.

5. The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force according to Claim 1 , comprising the variable pitch spring (2) that provides controlled reduction of resistance by bringing the coils into contact with each other under compression by regularly increasing and decreasing the spring pitches (a, b, c).

6. The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force according to Claim 1 or Claim 5, comprising spring pitches (a, b, c) which, when force is applied to the variable pitch spring (2), reduce the sensor resistance by 60%-80% compared to the case when no force is applied, by being regularly increased and decreased.

7. The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force according to Claim 1 , comprising linearly increasing spring pitches (a,b,c).

8. The soft spring-shaped sensor with variable spring pitch and magnetic connections, capable of measuring compression force according to Claim 1 , comprising spring pitches (a,b,c) where the length of the spring pitch a is shorter than the length of the spring pitch b and the length of the spring pitch b is shorter than the length of the spring pitch c

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