CN110274569B

CN110274569B - Sensor calibration system

Info

Publication number: CN110274569B
Application number: CN201910667986.0A
Authority: CN
Inventors: 别东洋; 韩建达; 林家能
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 2019-07-23
Filing date: 2019-07-23
Publication date: 2020-11-03
Anticipated expiration: 2039-07-23
Also published as: CN110274569A

Abstract

A sensor calibration system relates to a calibration device, which comprises a motor, an angle measurer, a transmission shaft, a roller with a groove, a flexible rope and a support frame; the motor is installed on the support frame, and the transmission shaft is connected to the output of motor, and the transmission shaft rotates to be installed on the support frame, and the cartridge has grooved gyro wheel on the transmission shaft, still installs the angular surveying ware of measuring gyro wheel rotation angle on the transmission shaft, and the inslot of gyro wheel is around having flexible rope, and the lower extreme of flexible rope is fixed on the current tensile elastic sensor who installs on the support frame. The invention has compact structure and reasonable design, and realizes the dynamic response capability under different deformation speeds, thereby completing the comprehensive calibration.

Description

Sensor calibration system

Technical Field

The invention relates to a calibration device, in particular to a sensor calibration system.

Background

In the field of flexible robots, elastic sensors are commonly used to measure the amount of flexible body deformation. Before the elastic sensor is used, the sensor needs to be calibrated to obtain the corresponding relation between the input quantity and the output quantity, and the static indexes (linearity, sensitivity, hysteresis and the like) and the dynamic indexes (response time and the like) of the sensor are determined.

At present, two calibration modes for the elastic sensor are mainly adopted, namely manual calibration and automatic calibration. The manual calibration means that the displacement input quantity of the elastic sensor is manually kept at a certain value, then the electric signal output quantity of the elastic sensor is measured, and the experiment is continuously repeated to obtain the input-output relation. The calibration mode is extremely complicated when the required data volume is large, the error is large, and the dynamic characteristic of the sensor cannot be obtained.

The automatic calibration means that an automatic calibration system is designed, a calibration range is set manually, the displacement input quantity of the sensor is changed by the system, and the output of the sensor is measured at the same time, so that calibration is completed. But the prior automatic calibration has poor comprehensive calibration performance and cannot meet the actual requirement.

Disclosure of Invention

The invention provides a sensor calibration system with convenient arrangement and comprehensive functions to overcome the defects of the prior art.

The technical scheme of the invention is as follows:

a sensor calibration system comprises a motor, an angle measurer, a transmission shaft, a roller with a groove, a flexible rope and a support frame; the motor is installed on the support frame, and the transmission shaft is connected to the output of motor, and the transmission shaft rotates to be installed on the support frame, and the cartridge has grooved gyro wheel on the transmission shaft, still installs the angular surveying ware of measuring gyro wheel rotation angle on the transmission shaft, and the inslot of gyro wheel is around having flexible rope, and the lower extreme of flexible rope is fixed on the current tensile elastic sensor who installs on the support frame.

Further, the angle measurer is a shaft sleeve encoder.

Further, the shaft sleeve encoder is an incremental encoder.

Compared with the prior art, the invention has the following effects:

1. the calibration system adopts the motor to drive the elastic sensor to deform, the deformation quantity and the change speed can be set, and the precision is high.

2. The calibration system adopts the encoder to measure the actual rotation angle of the motor, and effectively reduces errors caused by factors such as motor transmission clearance and the like.

3. The calibration system can test the static index and the dynamic index of the elastic sensor, has comprehensive functions, can automatically complete the calibration process, and improves the efficiency.

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Drawings

FIG. 1 is a perspective view of a sensor calibration system of the present invention;

fig. 2 is a working principle diagram.

Detailed Description

Referring to fig. 1, a sensor calibration system of the present embodiment includes a motor 1, an angle measurer 2, a transmission shaft 3, a grooved roller 4, a flexible rope 6, and a support frame 7;

motor 1 installs on support frame 7, and transmission shaft 3 is connected to motor 1's output, and transmission shaft 3 rotates and installs on support frame 7, and the cartridge has grooved gyro wheel 4 on the transmission shaft 3, still installs the angular surveying ware 2 of measuring 4 rotation angles of gyro wheel on the transmission shaft 3, and the inslot of gyro wheel 4 is around having flexible rope 6, and the lower extreme of flexible rope 6 is fixed and is installed on the current tensile elastic sensor 5 on support frame 7.

The motor 1 can receive a control signal to realize the rotation of a specified speed in a clockwise or anticlockwise direction and a specified angle. In order to ensure that the rotating angle is consistent with a set value, the angle measurer 2 measures the actual rotating angle of the motor by using a shaft sleeve encoder to form a feedback signal, and further, the shaft sleeve encoder adopts an incremental encoder, so that the measurement is accurate and reliable. This axle sleeve encoder passes through the support mounting at support frame 7, and axle sleeve encoder suit is on transmission shaft 3, and in another embodiment, the axle sleeve encoder can be replaced by angle sensor, can play the effect of measuring 4 turned angles of gyro wheel equally. The bearing and the roller 4 are rigidly fixed without relative displacement, so that the rotation of the motor 1 can drive the roller to rotate by the same angle. The roller 4 and the elastic sensor 5 are connected by a flexible string 6 having a very small ductility, so that the displacement of the elastic sensor 5 is changed as specified. The technical scheme can realize the corresponding relation between the output electric signal of the automatic measurement elastic sensor and the deformation degree thereof and the dynamic response capability under different deformation speeds, thereby completing the comprehensive calibration of the automatic measurement elastic sensor.

In another embodiment, the support frame 7 includes an upper frame, a lower frame, and a support beam 73; the upper frame is a square frame assembled by four side section bars 71, a connecting section bar 72 parallel to two side section bars 71 is arranged in the square frame, a roller 4 is arranged between the connecting section bar 72 and one side section bar 71 parallel to the connecting section bar 72, an angle measurer 2 is arranged between the connecting section bar 72 and the other side section bar 71 parallel to the connecting section bar 72, a motor 1 is arranged on the other side section bar 71, and a transmission shaft 3 is supported by a bearing seat arranged on the connecting section bar 72 and the one side section bar 71 parallel to the connecting section bar 72; the lower frame is an H-shaped frame assembled by three side section bars 71, the upper frame is connected with the lower frame through a vertical supporting beam 73, and an elastic sensor 5 fixed by a sensing clamp is arranged on a transverse section bar of the H-shaped frame. The elastic sensor 8 is a plate-shaped structure, and the sensing clamp comprises a pair of upper clamping plates 91 and a pair of lower clamping plates 92; the pair of upper plates 91 fixedly hold the upper portion of the elastic sensor 5, and the pair of lower plates 92 fixedly hold the lower portion of the elastic sensor 5. By the arrangement, the static and dynamic indexes of the sensor are ensured to be calibrated stably.

Principle of operation

The system can drive the roller to rotate for a certain angle through a given motor control signal through the transmission shaft, and the elastic sensor generates elastic deformation through the stretching of the tension rope, and the upper end of the elastic sensor ascends or descends for a section of displacement. The angle of rotation can be measured by an encoder so that the amount of change in displacement can be derived. The output electric signal change of the elastic sensor can be measured by an external measuring circuit. Fig. 2 is a schematic diagram of displacement measurement, assuming that the angular variation measured by the encoder is θ, which is in rad, and R represents the radius of the circle at the wheel hub, the displacement variation L of the elastic sensor can be represented as:

L＝θR

during the static index test, the displacement variation range and the rotation speed are set artificially, the displacement is changed automatically by the calibration system, the electric signal quantity of the flexible sensor is measured in the deformation process, and the system repeats the operation until the range boundary value is reached.

When the dynamic index is tested, the real-time speed of the motor can be controlled, and the input and output quantity changes and the change time are recorded at the same time, so that indexes such as the response speed of the motor can be obtained.

The present invention is not limited to the above embodiments, and any simple modification, equivalent change and modification made by the technical essence of the present invention by those skilled in the art can be made without departing from the scope of the present invention.

Claims

1. A sensor calibration system, characterized by: the device comprises a motor (1), an angle measurer (2), a transmission shaft (3), a roller (4) with a groove, a flexible rope (6) and a support frame (7);

the motor (1) is installed on a support frame (7), the output end of the motor (1) is connected with a transmission shaft (3), the transmission shaft (3) is rotatably installed on the support frame (7), a roller (4) with a groove is inserted on the transmission shaft (3), an angle measurer (2) for measuring the rotation angle of the roller (4) is further installed on the transmission shaft (3), a flexible rope (6) is wound in the groove of the roller (4), and the lower end of the flexible rope (6) is fixed on an existing stretchable elastic sensor (5) installed on the support frame (7);

the support frame (7) comprises an upper frame, a lower frame and a support beam (73); the upper frame is a square frame assembled by four side section bars (71), a connecting section bar (72) parallel to two side section bars (71) is installed in the square frame, a roller (4) is arranged between the connecting section bar (72) and one side section bar (71) parallel to the connecting section bar, an angle measurer (2) is arranged between the connecting section bar (72) and the other side section bar (71) parallel to the connecting section bar, a motor (1) is installed on the other side section bar (71), and a transmission shaft (3) is supported by a bearing seat installed on the connecting section bar (72) and the one side section bar (71) parallel to the connecting section bar;

the lower frame is an H-shaped frame assembled by three side sectional materials (71), the upper frame is connected with the lower frame through a vertical supporting beam (73), and an elastic sensor (5) fixed by a sensing clamp is arranged on a transverse sectional material of the H-shaped frame.

2. A sensor calibration system as defined in claim 1, wherein: the angle measurer (2) is a shaft sleeve encoder.

3. A sensor calibration system as defined in claim 2, wherein: the shaft sleeve encoder is an incremental encoder.

4. A sensor calibration system as defined in claim 1, wherein: the angle measurer (2) is an angle sensor.

5. A sensor calibration system according to claim 1, 2, 3 or 4, characterized in that: the elastic sensor (5) is of a plate-shaped structure, and the sensing clamp comprises a pair of upper clamping plates (91) and a pair of lower clamping plates (92); the pair of upper clamping plates (91) fixedly clamp the upper part of the elastic sensor (5), and the pair of lower clamping plates (92) fixedly clamp the lower part of the elastic sensor (5).