TWI607200B - Real time sensor system - Google Patents

Description

Instant sensing system

The present invention relates to an instant sensing system, and more particularly to an instant sensing system that applies a high gain estimation algorithm to a sensing element instant detection technique with low pass response characteristics.

A sensor is a device that is capable of reacting a perceived physical signal to a signal that is easy to process or read based on a physical signal (eg, temperature, gas concentration). In order to achieve highly integrated applications, today's commercially available sensing components have become universal. In order to facilitate user development, most of the sensing components have been modularized. However, the physical phenomenon of the sensing component itself has transient characteristics, and after the sensing component is modularized, the function of signal processing, low-pass filtering noise suppression, etc., will cause the original physical quantity transient measurement. The response characteristics produce partial distortion.

In addition, in the case of a gas sensor, when the gas concentration measurement is performed, it is detected as a concentration by a reaction of an internal chemical substance. Based on the nature of the chemical reaction of the internal chemical itself, the concentration detection of the gas sensor will produce a certain degree of time delay. If the dynamic response of the gas sensor is insufficient, the concentration measurement will delay the output, which will cause the difference between the real environment concentration and the current measured concentration, that is, the immediacy of the gas concentration detection is insufficient. If the monitoring of toxic gases (such as carbon monoxide) is too slow to reflect the current concentration, it will pose a great hazard to the safety of personnel and the working environment.

In addition to affecting the immediacy of measurement, if the transient response of the sensor is applied to the control system, it will easily reduce the control bandwidth, resulting in a mismatch between the control target output and the actual reference input, resulting in stability of the control system. Reduced performance.

Therefore, it is necessary to provide an instant sensing system to solve the problems of the conventional technology.

The main purpose of the present invention is to provide an instant sensing system to shorten the sensing time, and at the same time, it can effectively suppress the measurement of noise and improve the accuracy and immediacy of the detection.

To achieve the above object, the present invention provides an instant sensing system comprising: a sensor for detecting an environmental physical quantity to provide a sensor response output; and an embedded microprocessor for receiving the response output And including a high gain estimator and a high frequency switching suppression filter, the high gain estimator estimates the response output according to a physical quantity detection equation, and then filters the high frequency switching suppression filter. Get an estimator response output.

In an embodiment of the invention, the mathematical model of the dynamic characteristics of the sensor for detecting is: Where τ is a time constant, u represents the actual environmental physical quantity input, and y _sensor represents the sensor response output; the mathematical model of the high gain estimator is: Where L is the estimator gain value; the physical quantity detection equation is: u _obs :=(1+ τL ) e _obs + τηsign ( e _obs ), where e _obs is the estimation error, e _obs = x _sensor - x _Obs ; The mathematical model of the high frequency switching suppression filter is: Where α is a given positive value and u _{est is} the estimator response output.

The invention mainly establishes a mathematical model of the estimator according to the mathematical model of the dynamic characteristics of the sensor itself under the output information of the low-frequency wide sensor, and uses a high-gain estimator algorithm to estimate the externality. Environmental physical quantity. The estimated output obtained has a high matching with the external environmental reference value, which can effectively compensate the measurement response of the sensor too slow, in addition to shortening the sensing time, and effectively suppressing the measurement noise to achieve accurate detection. The purpose of sex and immediacy.

10‧‧‧ Sensors

11‧‧‧ embedded microprocessor

110‧‧‧High Gain Estimator

111‧‧‧High frequency switching suppression filter

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of a system of an instant sensing system in accordance with a preferred embodiment of the present invention.

Figure 2 is a schematic diagram showing the mathematical model of the algorithm of the instant sensing system of the present invention.

Figure 3 is a schematic diagram showing the comparison of the measured responses of the estimator and the sensor of the instant sensing system of the present invention.

Figure 4 is a schematic diagram comparing the error response corresponding to Figure 3.

Figure 5 is a schematic diagram showing the comparison of the measured response of the estimator and the sensor with the temperature as the verification physical quantity of the instant sensing system of the present invention.

Figure 6 is a comparison of temperature error response corresponding to Figure 5.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The instant sensing system of the present invention is mainly suitable for sensing environmental physical quantities (such as temperature, gas concentration) and converting and quantizing, and using the estimator algorithm provided by the present invention to quickly estimate the physical quantity of the real environment and reduce the measurement. Error, reach Quick and immediate physical volume detection.

Please refer to FIG. 1 and FIG. 2 simultaneously. FIG. 1 is a system block diagram of an instant sensing system according to a preferred embodiment of the present invention; and FIG. 2 is a mathematical model architecture diagram of the algorithm. The instant sensing system of the present invention can mainly include a sensor 10 and an embedded microprocessor 11.

The sensor 10 is configured to detect a physical quantity of the environment to provide a sensor response output, and in particular a low frequency wide response sensor 10, as shown in FIG. 2, in an embodiment, for sensing The environmental physical quantity detected by the device 10 can correspond to the real physical quantity, and the dynamic characteristics of the sensor 10 can be described as a first-order system: Where τ is a time constant, the magnitude of which affects the measured output bandwidth of the sensor 10, and for a low frequency wide response sensor, can be regarded as a large value, and u represents the physical quantity input of the real environment, y _sensor indicates the response output for the sensor. The sensor 10 may be a temperature sensor, a humidity sensor, a gas sensor, or the like, depending on the application, but is not limited thereto.

As shown in FIG. 1 , the embedded microprocessor 11 is configured to receive the response output of the sensor 10, and then estimate the energy and real environment according to the sensor response output and its own estimation algorithm. The physor is close to the estimator response output. The embedded microprocessor 11 mainly includes a high gain estimator 110 and a high frequency switching suppression filter 111. The high gain estimator 110 estimates the response output of the sensor according to a physical quantity detecting equation. Passing the high frequency switching suppression filter 111 performs filtering to obtain an estimator response output.

Regarding the theoretical basis of the instant sensing system of the present invention, please refer to the following: On the actual measurement target, the aforementioned sensor 10 is designed to make y _sensor = u in the shortest time. However, since the aforementioned sensor 10 itself has dynamic delay characteristics, such as circuit filtering characteristics, chemical reaction characteristics, etc., the actual response output cannot immediately reflect the real environmental physical quantity. Therefore, in order to estimate the actual physical quantity sensing value through the dynamic delay output of the sensor, so that the measurement has the characteristics of immediate response, the mathematical model of the high gain estimator 110 is designed as follows: Where L is the estimator gain value; at this time, the estimated estimation error is: e _obs = x _sensor - x _obs ........(3); from the above equations (1), (2), and (3) The following error dynamic equations are available:

The estimated performance response of the above error dynamic equation can be described by the following error energy equation: Take a differential for the above formula (5): It can be seen from the above formula (6) that the following inequalities are satisfied by appropriately selecting the estimated gain: Will be guaranteed Where λ is an arbitrary value greater than zero, thus satisfying the characteristics of finite time convergence. According to the above formula (8), the conservative estimation error dynamics must satisfy: And the convergence rate of the estimated error can also be improved by increasing the estimated gain L for the transient estimation response.

Based on the above formula (9), the real environmental physical quantity can be estimated by the following physical quantity detection equation: u _obs :=(1+ τL ) e _obs + τηsign ( e _obs )........(10) In practice, in order to eliminate the high-frequency value switching in equation (10) and extract the estimated physical quantity implied in it, a high-frequency switching suppression filter can be designed as follows: In equation (12), α is a positive value, and u _out can be used as the final estimator response output.

Figure 3 is a schematic diagram showing the comparison of the measurement response of the estimator and the sensor of the instant sensing system of the present invention, wherein the curve drawn by the solid line is the reference physical quantity for the external environment, and is represented by the curve of the detection and the curve drawn by the chain line. The curve drawn by the sensor with the low-pass characteristic and the dotted line is the physical quantity calculated by the estimator. It can be clearly seen from the time domain response that the high gain estimator of the instant sensing system of the present invention can quickly estimate the true state through the sensor output with the delay characteristic. Environmental physical quantity with high frequency and wide response characteristics.

Figure 4 is the error response corresponding to Figure 3, and it can be seen that the high-gain estimator of the instant sensing system of the present invention is compared with the error response of the existing sensor with low-pass characteristics (the curve drawn by the chain line). It has a lower error response (curves drawn by dashed lines), which has a better transient measurement response.

Please refer to Figure 5 and Figure 6 for further example. Take temperature as the verification physical quantity. In Figure 5, the curve drawn by the solid line is the external temperature reference input, and the curve drawn by the chain line is the output of the temperature sensor module. The curve drawn by the dotted line is the estimated output of the estimator. Through the practice verification, it can be seen that the high-gain estimator of the instant sensing system of the present invention does have better transient measurement under the condition that only the temperature sensor information (as shown by the chain curve) is available. Responsive, and can predict transient changes in the external reference temperature of the reaction, and can quickly reflect the true temperature (as shown by the dashed curve). Figure 6 is a comparison of the temperature error response corresponding to Figure 5, and also shows the error response (A curve) compared to the temperature sensor. The high gain estimator of the present invention has a lower error response (B curve). The high gain estimator of the present invention has a better transient measurement response.

In summary, the present invention is mainly modeled by the mathematical model of the dynamic characteristics of the sensor itself under the output information of the low-frequency wide sensor, and is matched with the high-gain estimator algorithm developed by the technology. To estimate the physical quantity of the external environment. The estimated output obtained has a highly matching line with the external environmental reference value, which can effectively compensate the measurement response of the sensor too slow, in addition to shortening the sensing time, and effectively suppressing the measurement noise to achieve accurate detection. The purpose of sex and immediacy.

Although the invention has been disclosed in the preferred embodiments, it is not intended to be limiting In the present invention, those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention, and the scope of the present invention is defined by the scope of the appended claims. .

10‧‧‧ Sensors

11‧‧‧ embedded microprocessor

Claims (1)

An instant sensing system includes: a sensor for detecting an environmental physical quantity to provide a sensor response output; and an embedded microprocessor for receiving the response output and including a high gain estimator and a high-frequency switching suppression filter, the high-gain estimator estimates the response output according to a physical quantity detection equation, and then filters the high-frequency switching suppression filter to obtain an estimator response output, wherein The mathematical model of the dynamic characteristics of the sensor for detection is: Where τ is a time constant, u represents the actual environmental physical quantity input, and y _sensor represents the sensor response output; the mathematical model of the high gain estimator is: Where L is the estimator gain value; the physical quantity detection equation is: u _obs :=(1+τ L ) e _obs +τη sign ( e _obs ), where e _obs is the estimation error, e _obs = x _sensor - x _obs ; The mathematical model of the high frequency switching suppression filter is: Where α is a given positive value and u _{est is} the estimator response output.