CN206670838U - Changeable fluid flexibility force snesor based on pneumatic variation rigidity - Google Patents

Abstract

A variable-range flexible force sensor based on aerodynamic variable stiffness and its measurement method. The sensor includes a flexible substrate of a flat cuboid, and an air pressure cavity is arranged in the flexible substrate; End-to-end connected micro-carrier channels—the first micro-carrier channel and the second micro-carrier channel; the first micro-carrier channel is from the first port to the third port through the zigzag end-to-tail connection cavity; the second micro-carrier channel is from the second port The two ports are connected to the fourth port through the Z-shaped end-to-end cavity, the third port is connected to the fourth port, and two wires are respectively drawn from the first port and the second port to connect the signal acquisition module; the first micro The carrying channel and the second micro-carrying channel are filled with liquid piezoresistive sensitive elements. The utility model changes the measuring range of the sensor by adjusting the stiffness change, realizes the variable range measurement of the force, and changes the current flexible sensor which is only used in the measurement of the small range force field.

Description

Variable range flexible force sensor based on aerodynamic variable stiffness

technical field

The utility model belongs to the field of detection devices for force measurement and control, in particular to a variable range flexible force sensor based on aerodynamic variable stiffness, which is used in the precise measurement of flexible large bearing capacity, and improves the range and precision of the flexible force sensor .

Background technique

In the exploration of the frontier field of robotics, the research and development of robotics is steadily advancing towards national key strategic fields such as high-end manufacturing, medical rehabilitation, and national defense security. In the force detection technology of robots, the flexible force detection technology is characterized by its high adaptability, suppleness sex, has been developing rapidly in recent years. Most of the current flexible sensors use flexible large-deformation materials as the substrate, and the nonlinear deformation of the flexible substrate leads to insufficient linearity of the flexible sensor in the case of large-scale measurement.

In order to overcome this kind of problem, the current domestic and foreign research mainly focuses on the research of structure optimization and control algorithm, and does not study from the angle of variable stiffness.

Contents of the invention

The utility model overcomes the shortcomings in the prior art, and provides a variable-range flexible force sensor based on aerodynamic variable stiffness.

In order to solve the above-mentioned technical problems, the utility model is achieved through the following technical solutions:

A variable-range flexible force sensor based on aerodynamic variable stiffness, comprising a flat rectangular parallelepiped flexible substrate 1, an air pressure cavity 2 is provided at the main bearing part inside the flexible substrate 1, and the air pressure cavity is provided with an air inlet 4 ; In the flexible matrix 1, the upper part of the air pressure cavity is provided with two layers of Z-shaped end-to-end micro-carrying channels—the first micro-carrying channel 3 and the second micro-carrying channel 10; the first micro-carrying channel 3 from the first port 6 to the third port 8 through the zigzag end-to-end cavity; the second microcarrier channel 10 is from the second port 7 to the fourth port 9 through the zigzag end-to-end cavity, The third port 8 of the first micro-carrier channel 3 communicates with the fourth port 9 of the second micro-carrier channel 10, and two wires are respectively drawn from the first port 6 and the second port 7 to connect the signal acquisition Module; the first micro-carrier channel 3 and the second micro-carrier channel 10 are filled with liquid piezoresistive sensitive elements.

Due to the adoption of the above-mentioned technical scheme, the variable-range flexible force sensor based on aerodynamic variable stiffness proposed by the utility model has the following beneficial effects compared with the prior art:

The utility model introduces the mechanism of aerodynamic variable stiffness, and changes the range of the sensor by adjusting the stiffness change of the force detection position of the sensor, which solves the problem of limited application caused by insufficient range in the actual application of the flexible sensor with a flexible large deformation material as the base, and improves The application value of the large deformation flexible sensor under the condition of large load is realized, and the variable range measurement of the force is realized, which changes the current flexible sensor which is only used in the measurement of the small range force field. In addition, the utility model has a simple body structure, small size, light weight, and strong flexibility. While detecting the force, it can buffer the force and reduce the damage of the force to both sides of the force; it has stable performance, acid and alkali corrosion resistance, and can overcome harsh conditions. environment, it can be used stably in extreme environments such as mines and oceans; it is not corroded by human sweat, non-toxic, and can be in direct contact with the skin. Therefore, the utility model can be widely used in industrial production, rehabilitation medical treatment, national defense and military industry.

Description of drawings

Fig. 1 is a structural diagram of a variable range flexible force sensor based on aerodynamic variable stiffness of the present invention;

Figure 2 is an enlarged view of direction A in Figure 1;

Fig. 3 is an enlarged schematic view of the microchannel in a variable range flexible force sensor based on aerodynamic variable stiffness of the present invention;

Fig. 4 is a flow chart of a measurement method of a variable-range flexible force sensor based on aerodynamic variable stiffness of the present invention.

In the figure: 1 is the flexible substrate of the sensor, 2 is the air pressure cavity, 3 is the first micro-bearing channel, 4 is the air inlet, 5 is the lead wire, 6 is the first port, 7 is the second port; 8 is the second port Three ports, 9 is the fourth port; 10 is the second micro bearer channel.

detailed description

The utility model will be described in detail below in conjunction with the accompanying drawings.

A variable-range flexible force sensor based on aerodynamic variable stiffness, as shown in Figure 1-3, it includes a flat rectangular parallelepiped flexible base 1, and an air pressure cavity 2 is provided at the main bearing part inside the flexible base 1, the described The air pressure cavity is provided with an air inlet 4; an air inlet 4 is provided at the end of the sensor, leading to an air intake pipe, and a micro air pressure input and control device is connected externally to control the pressure inside the air pressure cavity. The upper part of the air pressure cavity in the flexible matrix 1 is formed with two upper and lower layers of Z-shaped end-to-end micro bearing channels—the first micro bearing channel 3 and the second micro bearing channel 10; the first micro bearing channel The channel 3 is from the first port 6 to the third port 8 through the zigzag end-to-end cavity; the second microcarrier channel 10 is from the second port 7 to the fourth port 9 through the zigzag end-to-end cavity , the third port 8 of the first micro-carrier channel 3 communicates with the fourth port 9 of the second micro-carrier channel 10, and two wires are respectively drawn from the first port 6 and the second port 7 to connect signals Acquisition module; the first micro-carrier channel 3 and the second micro-carrier channel 10 are filled with liquid piezoresistive sensitive elements. Gallium indium tin alloy or other liquid piezoresistive materials that meet the performance requirements are the sensitive elements; in order to ensure the flexibility of the sensor, flexible glue is used at the fluid to achieve overall sealing. At the same time, it can ensure the stability of the sensor working in harsh environments.

1 in the figure is a structural diagram of a variable-range flexible force sensor based on aerodynamic variable stiffness of the present invention. The flexible substrate 1 of the sensor is used as the main load-bearing structure of the flexible sensor, and is made of flexible silicone rubber or other high-elastic materials that meet performance requirements. become.

Figure 2 is an enlarged view of the A direction in Figure 1. The air pressure cavity 2 formed from the flexible substrate of the sensor is the variable stiffness module of the sensor. The overall stiffness of the sensor is changed by passing a certain pressure of gas into the pneumatic cavity. , so that when the sensor is stretched, a certain internal stress is generated in the transverse direction, which can resist the stretching of the flexible substrate.

The microchannel carrying the sensitive element of the sensor is divided into upper and lower layers. As shown in Figure 3, the upper part is the first microcarrying channel, which is introduced from the first port 6 and distributed in a Z shape to the third port 8, and then to the third port 8. The lower part is that the second micro-carrier channel is introduced from the second port 7 and distributed in a zigzag to the fourth port 9; the micro-carrier cavity is filled with liquid piezoresistive sensitive elements, such as liquid gallium indium tin alloy, etc. Materials with piezoresistive properties that meet the requirements. The diameter of the first micro-carrying channel and the second micro-carrying channel is 0.01mm, and the one-way length is 65mm; the resistance value of the liquid sensitive element is 5mΩ-20mΩ. 4 in the figure is the air inlet leading into the variable stiffness module of the sensor, with a diameter of 3mm, which is connected to the micro air source through the rubber hose. Wherein, the interface is sealed with flexible glue.

Number 5 in Figure 1 shows two lead wires, which are respectively led out from ports 6 and 7 of the microchannel, and through the processing circuit, the received signal of the sensor is transferred to the acquisition card to measure the output force. The leads are also sealed with flexible glue.

According to the measurement method of a variable-range flexible force sensor based on aerodynamically variable stiffness of the present invention, as shown in Figure 4, when the sensor is stretched, the flexible substrate is stretched and deformed, and the internal micro-carrying channel becomes longitudinally longer and the cross-section becomes longer. Small, resulting in the total resistance of the internal liquid components carried by the load becomes larger, through the Wheatstone bridge, the resistance value to be detected is converted into a voltage value, and the voltage signal is output; the output signal of the sensor is detected by the signal acquisition system to judge the measurement Whether it exceeds the current range of the sensor, if this measurement does not exceed the current range of the sensor, output the measurement result of the sensor, which is an accurate value; and when the force of the sensor is too large and the tensile deformation of the substrate is greater than 20%, The non-linearity of the sensor signal increases significantly. If the measurement exceeds the current range of the sensor, the control air source will input a certain pressure of gas into the air pressure cavity 2 of the sensor to increase the overall stiffness of the sensor, so that the sensor is subjected to a large load. The deformation in the micro-carrying channel in the matrix can still be kept in the linear region, which increases the measurement range of the sensor and improves the accuracy of the measurement; because the material used is a superelastic incompressible material, so by affecting the lateral direction of the sensor Therefore, it can be equivalent to changing the stiffness of the sensor substrate 1, thereby reducing the force deformation of the sensor, and improving the measurement range of the sensor in the linear region; repeat the signal The process of detecting, judging and changing the stiffness is until the signal output by the sensor in its deformation linear region is detected, and finally the magnitude of the force to be measured can be obtained according to the final output signal and the pressure of the gas passed in.

Under the premise of not departing from the essence of the present utility model, adopt various different forms of realization methods, without creatively designing structural shapes or layouts similar to the utility model (as changing the distribution and size of microchannels and variable stiffness modules etc.), all belong to the protection scope of the present utility model.

Claims (1)

1. A kind of 1. changeable fluid flexibility force snesor based on pneumatic variation rigidity, it is characterised in that：The sensor includes prolate side The flexible substrate (1) of body, an air pressure cavity (2) is provided with the internal main carrying position of flexible substrate (1), described air pressure is empty Chamber is provided with air inlet (4)；Upper and lower two layers of Z-shaped head and the tail are provided with the flexible substrate (1) positioned at air pressure cavity top to connect Micro- bearer path --- first micro- bearer path (3) and second micro- bearer path (10)；First micro- bearer path (3) is certainly First port (6) is through the cavity that Z-shaped head and the tail connect to the 3rd port (8)；Second micro- bearer path (10) is from the second end The cavity of head and the tail connection of mouthful (7) through Z-shaped is to the 4th port (9), the 3rd port (8) of first micro- bearer path (3) It is connected with the 4th port (9) of described second micro- bearer path (10), draws respectively from first port (6) and second port (7) Go out two wires to connect signal acquisition module；First micro- bearer path (3) and second micro- bearer path (10) fill Liquid resistance sensing element of pressure.