CN102759355B - Positioning estimation method and positioning system - Google Patents

Abstract

The invention discloses a positioning estimation method and a positioning system, wherein the positioning estimation method is used for a positioning system with a plurality of inertial sensors, the plurality of inertial sensors are arranged on an object, and the positioning estimation method comprises the steps of sensing the motion state of the object by using the plurality of inertial sensors to generate a plurality of sensing signals; selecting a plurality of candidate sensing signals within an error range from the plurality of sensing signals according to a fault tolerance threshold; and calculating an estimated position of the object according to the candidate sensing signals.

Description

Position Estimation Method and Positioning System

technical field

The invention relates to a positioning estimation method and a related positioning system, in particular to a positioning estimation method and a related positioning system capable of improving reliability.

Background technique

Three-dimensional space (Three Dimension, 3D) positioning technology has been widely used in the application of various electronic products. Known positioning methods usually use two or more different inertial sensors to cooperate with each other to achieve the effect of object positioning. However, since different types of inertial sensors have different response speeds, the response time is of course different. As a result, the signal output time of each inertial sensor will not be consistent. For example, if the detection time of the gyroscope is 1/720 second per degree, and the gravity sensor is 1/1600 second per degree, in this case, the positioning information of the object at a certain position will be sensed at different times Signals are estimated to produce erroneous positioning results.

On the other hand, since the inertial sensor usually senses in a motion state (time-continuous), that is, the sensed signal is a signal value calculated by integrating time. Furthermore, usually the inertial sensor itself will have some sensing errors. In this case, as time goes on, the sensing errors will also accumulate over time. Therefore, the longer the time, the error caused by the integral operation The obtained values are also larger, so if the inertial sensor is used in a long-term sensing operation, inaccurate sensing results will be produced.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a positioning estimation method and a related positioning system.

The invention discloses a positioning estimation method for a positioning system with multiple inertial sensors, wherein the multiple inertial sensors are arranged on an object, and the positioning estimation method includes using the multiple inertial sensors to sense the object a motion state to generate a plurality of sensing signals; according to an error-tolerant threshold, selecting a plurality of candidate sensing signals within an error range from the plurality of sensing signals; and according to the plurality of candidate sensing signals, An estimated position of the object is calculated.

The invention also discloses a positioning system for estimating the position of an object, which includes a plurality of inertial sensors, a signal processing unit and a position calculation unit. The multiple inertial sensors are arranged on the object to sense the motion state of the object to generate multiple sensing signals. The signal processing unit includes a signal receiving unit and an error-tolerant detection unit. The signal receiving unit is coupled to the plurality of inertial sensors for receiving the plurality of sensing signals. The error-tolerant detection unit is coupled to the signal receiving unit, and is used for selecting a plurality of candidate sensing signals within an error range from the plurality of sensing signals according to an error-tolerant threshold. The position calculation unit is coupled to the fault-tolerant detection unit, and is used for calculating an estimated position of the object according to the plurality of candidate sensing signals.

Description of drawings

FIG. 1 is a schematic diagram of a positioning system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a process of an embodiment of the present invention.

FIG. 3 is a signal waveform diagram of the sensing signal in FIG. 1 .

FIG. 4 is a schematic diagram when the positioning system in FIG. 1 is applied to an electronic pen.

[Description of main component symbols]

10 positioning system

102 signal processing unit

104 position operation unit

106 signal receiving unit

108 fault-tolerant detection units

110 zero reset unit

20 process

200, 202, 204, 206,

208 steps

IS1～IS3 inertial sensors

OB object

S1～S3 sensing signal

SAB1 abnormal sensing signal

SC1～SC2 Candidate Sensing Signals

detailed description

Please refer to FIG. 1 , which is a schematic diagram of a positioning system 10 according to an embodiment of the present invention. The positioning system 10 is used to estimate the position of an object OB. The positioning system 10 includes inertial sensors IS1 - IS3 , a signal processing unit 102 , and a position calculation unit 104 . The inertial sensors IS1-IS3 are respectively disposed on the object OB for sensing the motion state of the object OB to generate sensing signals S1-S3. The signal processing unit 102 includes a signal receiving unit 106 , an error detection unit 108 and a reset unit 110 . The signal receiving unit is coupled to the inertial sensors IS1-IS3 for receiving the sensing signals S1-S3. The error tolerance detection unit 108 is coupled to the signal receiving unit 106 and is used for selecting a plurality of candidate sensing signals within the error range from the sensing signals S1 - S3 according to an error tolerance threshold. The zero reset unit 110 is coupled to the inertial sensors IS1-IS3 and the fault-tolerant detection unit 108, and is used to control the inertial sensors IS1-IS3 to execute a zero-reset process. The position calculation unit 104 is coupled to the fault-tolerant detection unit 108 and used for calculating the estimated position of the object OB according to the selected candidate sensing signals. In other words, the positioning system 10 can estimate the corresponding position of the object OB in the three-dimensional space. In this way, if the positioning system 10 estimates the position of the object OB at different times, the trajectory of the object OB can be determined. .

For the detailed operation of the positioning system 10 , please continue to refer to the following description. Please refer to FIG. 2 , which is a schematic diagram of a process 20 according to an embodiment of the present invention. Process 20 includes the following steps:

Step 200: start.

Step 202: Use the inertial sensors IS1-IS3 to sense the motion state of the object OB to generate sensing signals S1-S3.

Step 204: Select a plurality of candidate sensing signals within the error range from the sensing signals S1-S3 according to the error tolerance threshold.

Step 206: Calculate the estimated position of the object OB according to the selected candidate sensing signals.

Step 208: end.

According to the process 20, firstly, the motion state of the object OB is sensed by using the inertial sensors IS1-IS3 respectively, and the sensing signals S1-S3 are generated accordingly (step 202). Incorrect sensing signals may be generated by the inertial sensor due to long-term accumulated sensing errors or the influence of the installation position, or even failure. In this case, the fault-tolerant detection unit 108 can analyze and filter the sensing signals S1-S3 received by the signal receiving unit 106, so as to select a suitable error range from the sensing signals S1-S3 according to a fault-tolerant threshold value. The candidate sensing signals in the object OB (step 204), and then, the position calculation unit 104 calculates the estimated position of the object OB according to the selected candidate sensing signals (step 206). In other words, the present invention uses a fault-tolerant design method to exclude improper (beyond the allowable error range) sensing signals, so as to improve the reliability of position estimation, and obtain more accurate object positioning information.

To further illustrate, in step 204 , the fault-tolerant detection unit 108 can distinguish all sensing signals as candidate sensing signals or abnormal sensing signals. That is to say, the fault-tolerant detection unit 108 can select the sensing signals within the error range from the sensing signals S1-S3 as candidate sensing signals according to the fault-tolerant threshold value, so as to provide subsequent object position estimation operations. At the same time, the sensing signals beyond the error range are selected as abnormal sensing signals, instead of being used as data for subsequent object position estimation calculations. For example, please refer to FIG. 3 , which is a signal waveform diagram of the sensing signals S1 - S3 in FIG. 1 . Assuming that the error tolerance threshold value is TH, and at the time point T, when the inertial sensor IS3 generates a sensing signal S3 that exceeds the error range due to abnormal sensing, as shown in Figure 3, at the time point T, the inertial sensor IS3 There is a large difference between the sensed signal value of the sensing signal S3 and the signal value of the sensing signal S2 sensed by the adjacent inertial sensor IS2. Therefore, in step 204, the fault-tolerant detection unit 108 can compare each sensing signal with the corresponding sensing signals of adjacent inertial sensors to calculate the corresponding signal difference value, and when the calculated signal difference value is less than the fault-tolerant threshold When the limit value TH is within the error range, the fault-tolerant detection unit 108 selects the sensing signal as a candidate sensing signal. Similarly, when the calculated signal difference value is not less than the error tolerance threshold TH (that is, exceeds the error range), the sensing signal is selected as an abnormal sensing signal. In other words, the fault tolerance detection unit 108 may select the sensing signals S1 and S2 as the candidate sensing signals SC1 and SC2 , and set the sensing signal S3 as the abnormal sensing signal SAB1 . Next, in step 206 , the position calculation unit 104 calculates the estimated position of the object OB only according to the candidate sensing signals SC1 and SC2 so as to avoid improper data from affecting the position estimation of the object OB.

In addition, since the inertial sensors are disposed on the same object, the sensing signal values sensed by normal sensors at the same time point usually do not have much difference. Therefore, the error-tolerant detection unit 108 can also calculate the corresponding signal difference value by comparing each sensing signal with the signal average value of other sensing signals. When the calculated signal difference value is smaller than the error tolerance threshold, the error tolerance detection unit 108 may select the corresponding sensing signal as a candidate sensing signal. Similarly, when the calculated signal difference value is not less than the error tolerance threshold, the corresponding sensing signal is selected as an abnormal sensing signal.

On the other hand, in step 204 , when the fault-tolerant detection unit 108 selects the abnormal sensing signal, the zero-resetting unit 110 can control the inertial sensors IS1 - IS3 to execute a zero-resetting process. For example, through the control of the zero-reset unit 110, the inertial sensors IS1-IS3 will temporarily stop the sensing process within a zero-reset processing period, so that the inertial sensors that sense abnormal sensing signals In other words, the situation of abnormal sensing can be improved. In the subsequent sensing process, the inertial sensor that has been reset to zero will be able to correctly sense the motion state of the object again. In addition, in order to eliminate the incorrect sensing signal generated by the inertial sensor due to the long-term accumulated sensing error, even if the inertial sensor in the positioning system 10 does not generate a sensing signal beyond the error range, the zero reset unit 110 At intervals of a specific cycle, the zeroing and reset processing procedure is executed sequentially for the inertial sensors IS1~IS3. In this way, it is equivalent to recalculating the time, and performing a reset operation on the estimated position of the object in a short period of time, which can eliminate the Sensing error caused by time to prevent the occurrence of incorrect sensing signals.

In addition, in step 206 , the position calculation unit 104 calculates the estimated position of the object OB according to the selected candidate sensing signals. For example, the position calculation unit 104 can calculate the average value of the selected candidate sensing signals to determine the estimated position of the object OB. Since the inertial sensors IS1 - IS3 are disposed at different positions on the object OB, correspondingly, the sensing sensitivities are also different. Therefore, the position calculation unit 104 can perform weight calculation on the selected candidate sensing signals according to a weight distribution ratio, and determine the estimated position of the object OB accordingly. Preferably, the above-mentioned weight distribution ratio is corresponding to the installation position of each corresponding inertial sensor, for example, a position with a lower sensitivity is given a smaller weight, and vice versa. In this way, the installation positions of each inertial sensor are different Giving different weights can eliminate the influence of uneven sensitivity, thereby increasing the reliability of the three-dimensional space position estimation.

It is worth noting that the above examples are only used to illustrate the application of the present invention, and are not limitations of the present invention. Those skilled in the art should understand that without departing from the spirit of the present invention, the steps in the flow chart in Figure 2 can be Additional intermediate steps can be added, several steps can be combined into a single step, or some steps can be omitted to make appropriate changes. Of course, if substantially the same result can be obtained, the process 20 in FIG. 2 is not limited to be executed according to the sequence shown in FIG. 2 . In addition, the positioning system 10 is an embodiment of the present invention, and those skilled in the art may make various changes accordingly. For example, the signal receiving unit 106 can be connected to the inertial sensors IS1 - IS3 in a wireless or wired manner to obtain corresponding sensing signals. Similarly, the zero reset unit 110 can also communicate with the inertial sensors IS1 - IS3 in a wireless or wired manner, so as to control the corresponding inertial sensors to perform zero reset processing. In addition, the inertial sensors described in the present invention are not limited to any type and quantity, and any device that can provide relevant physical quantity information of object motion is applicable. For example, whether it is a three-axis acceleration sensor, a gravity sensor, a gyroscope or an electronic compass, etc., all belong to the applicable scope of the present invention, but not limited thereto.

The following further uses an electronic pen as an example for illustration. Please refer to FIG. 4 , which is a schematic diagram of the positioning system 10 of FIG. 1 applied to an electronic pen. Assume that the object OB is an electronic pen, the inertial sensors IS1 - IS3 are respectively a three-axis acceleration sensor, and the error tolerance threshold is TH. When the user intends to perform three-dimensional drawing by operating the object OB, the position of the object OB at different times can be estimated through the operation of the positioning system 10. In this way, the trajectory of the object OB can be determined and the drawing can be realized. the goal of. In detail, firstly, the inertial sensors IS1-IS3 can be used to sense the motion state of the object OB, and the sensing signals S1-S3 can be generated accordingly. For example, at time T, the signal value of the sensing signal S1 is (X1, Y1, Z1), the signal value of the sensing signal S2 is (X2, Y2, Z2), and the signal value of the sensing signal S3 is (X3, Y3, Z3). Next, the error-tolerant detection unit 108 is used to compare each sensing signal with the corresponding sensing signal of its adjacent inertial sensor. If the signal difference between the sensing signals S1 and S2 is smaller than the error tolerance threshold TH and the signal difference between the sensing signals S3 and S2 is larger than the error tolerance threshold TH, the error detection unit 108 may select the sensing signals S1 and S2 as The candidate sensing signals SC1 and SC2 are selected, and the sensing signal S3 is set as the abnormal sensing signal SAB1. Then, the position computing unit 104 can calculate the estimated position of the object OB according to the candidate sensing signals SC1 and SC2 . Of course, since the data of the sensing signal S3 has exceeded the allowable error range, it will be excluded and not used as a basis for position calculation. In addition, since the inertial sensor IS1 is closer to the tip of the pen, the sensing sensitivity may be greater, so a greater weight ratio is given. For example, the weight ratios corresponding to the candidate sensing signals SC1 and SC2 are respectively W1 and W2, wherein W1 is greater than W2, if the estimated position of the object OB at time T is the coordinate value (X, Y, Z), then X=(W1*X1)+(W2*X2), Y=(W1*Y1)+(W2*Y2), Z=(W1*Z1)+(W2*Z2). In addition, due to the existence of the abnormal sensing signal SAB1, the zero reset unit 110 will control the inertial sensors IS1-IS3 to perform the zero reset processing procedure according to the abnormal sensing signal SAB1, and re-perform the time integration operation. Therefore, the inertial sensor IS3 that senses the abnormal sensing signal SAB1 can eliminate the accumulated sensing error during the original operation. In other words, the positioning system 10 can not only eliminate incorrect sensing signals and avoid affecting the estimation of the correct position, but also perform a zero reset process on the inertial sensors with accumulated errors, so that they can be used in subsequent sensing. During the measurement process, the motion state of the object can be correctly sensed again.

To sum up, the present invention uses a fault-tolerant design method to eliminate incorrect sensing signals, thereby effectively improving the reliability of position estimation. On the other hand, the present invention combines zero reset processing to eliminate the cumulative error of the inertial sensor, and gives different weights to each inertial sensor according to the different setting positions, so as to eliminate the influence of uneven sensitivity, and then obtain more Accurate object positioning information.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (21)

1. a location estimation method, for having an alignment system of multiple inertial sensor, the most the plurality of inertial sensor is arranged on an object, and this location estimation method includes:

The plurality of inertial sensor is utilized to sense the kinestate of this object, to produce multiple sensing signal；

The fault-tolerant threshold value arranged according to the accumulative sensing error for inertial sensor, selects together in the multiple candidate's sensing signals in range of error in the plurality of sensing signal；And

According to the plurality of candidate's sensing signal, calculate an estimation position of this object.

2. location estimation method as claimed in claim 1, wherein according to this fault-tolerant threshold value, selects the step together in the multiple candidate's sensing signals in range of error in the plurality of sensing signal and includes:

For each sensing signal, relatively each sensing signal is adjacent the sensing signal corresponding to inertial sensor, to determine a signal difference value；And

When this signal difference value is less than this fault-tolerant threshold value, select this corresponding sensing signal as candidate's sensing signal.

3. location estimation method as claimed in claim 1, wherein according to this fault-tolerant threshold value, selects the step together in the multiple candidate's sensing signals in range of error in the plurality of sensing signal and includes:

For a signal averaging of each sensing signal, relatively this sensing signal each with other sensing signals, to determine a signal difference value；And

When this signal difference value is less than this fault-tolerant threshold value, select this corresponding sensing signal as candidate's sensing signal.

4. location estimation method as claimed in claim 1, wherein according to this fault-tolerant threshold value, selects the step together in the multiple candidate's sensing signals in range of error in the plurality of sensing signal and also includes:

The plurality of sensing signal will not be chosen for candidate sensing signal person, selected as an abnormal sensing signal；And

When there are this exception sensing signal, to the plurality of inertial sensor, perform a zero reset process program.

5. location estimation method as claimed in claim 4, wherein when there are this exception sensing signal, to the plurality of inertial sensor, the step performing this zero reset process program includes:

Within a zero reset process cycle, stop the kinestate utilizing the plurality of inertial sensor to sense this object.

6. location estimation method as claimed in claim 1, wherein according to the plurality of candidate's sensing signal, the step of this estimation position calculating this object includes:

According to a weight allocation proportion, the plurality of candidate's sensing signal is computed weighted, and determine this estimation position of this object according to this.

7. location estimation method as claimed in claim 6, wherein this weight allocation proportion corresponds to the position of the plurality of inertial sensor.

8. location estimation method as claimed in claim 1, wherein according to the plurality of candidate's sensing signal, the step of this estimation position calculating this object includes:

Calculate a meansigma methods of the plurality of candidate's sensing signal, to determine this estimation position of this object.

9. location estimation method as claimed in claim 1, it also includes:

Every a specific period, sequentially to the plurality of inertial sensor, perform a zero reset process program.

10. an alignment system, is used for estimating the position of an object, includes:

Multiple inertial sensors, are arranged on this object, are used for sensing the kinestate of this object, to produce multiple sensing signal；

One signal processing unit, includes:

One signal receiving unit, is coupled to the plurality of inertial sensor, is used for receiving the plurality of sensing signal；And

One fault-tolerant detector unit, is coupled to this signal receiving unit, is used for the fault-tolerant threshold value arranged according to the accumulative sensing error for inertial sensor, selects together in the multiple candidate's sensing signals in range of error in the plurality of sensing signal；And

One position arithmetic element, is coupled to this fault-tolerant detector unit, is used for, according to the plurality of candidate's sensing signal, calculating an estimation position of this object.

11. alignment systems as claimed in claim 10, the sensing signal that wherein this more each inertial sensor of fault-tolerant detector unit is sensed is adjacent the sensing signal corresponding to inertial sensor, to determine a signal difference value, and when this signal difference value is less than this fault-tolerant threshold value, select this corresponding sensing signal as candidate's sensing signal.

12. alignment systems as claimed in claim 10, the sensing signal that wherein this more each inertial sensor of fault-tolerant detector unit is sensed and a signal averaging of the sensing signal corresponding to other inertial sensors, to determine a signal difference value, and when this signal difference value is less than this fault-tolerant threshold value, select this corresponding sensing signal as candidate's sensing signal.

13. alignment systems as claimed in claim 10, wherein this fault-tolerant detector unit will not be chosen for candidate sensing signal person in the plurality of sensing signal, selected as an abnormal sensing signal.

14. alignment systems as claimed in claim 10, wherein this signal processing unit also includes:

One zero reset cell, is coupled to the plurality of inertial sensor and this fault-tolerant detector unit, is used for controlling the plurality of inertial sensor, performs a zero reset process program.

15. alignment systems as claimed in claim 14, wherein this zero reset cell is within a zero reset process cycle, controls the plurality of inertial sensor and stops sensing the kinestate of this object.

16. alignment systems as claimed in claim 14, wherein this zero reset cell is every a specific period, sequentially to the plurality of inertial sensor, performs a zero reset process program.

17. alignment systems as claimed in claim 10, wherein this position arithmetic element is according to a weight allocation proportion, computes weighted the plurality of candidate's sensing signal, and determines this estimation position of this object according to this.

18. alignment systems as claimed in claim 17, wherein this weight allocation proportion system corresponds to the position of the plurality of inertial sensor.

19. alignment systems as claimed in claim 10, wherein this position arithmetic element calculates a meansigma methods of the plurality of candidate's sensing signal, and determines this estimation position of this object according to this.

20. alignment systems as claimed in claim 10, the most the plurality of inertial sensor is respectively one or three axle acceleration sensors, a gravity sensor, a gyroscope or an electronic compass.

21. alignment systems as claimed in claim 10, the most the plurality of inertial sensor is respectively arranged at the diverse location of this object.