Optical navigation die and optical navigation system with displacement synchronization mechanism

Abstract

This invention discloses an optical navigation chip and an optical navigation system with a displacement synchronization mechanism. The optical navigation chip is used in the processing unit of the optical navigation system with a displacement synchronization mechanism. The optical navigation chip includes a tracking module, a decoder, a readout buffer, and an accumulation buffer. The tracking module is used to generate detection data. The decoder is used to receive trigger events. The readout buffer is connected to the processing unit via a communication interface. The accumulation buffer connects the tracking module, the decoder, and the readout buffer. The accumulation buffer stores the detection data from the tracking module, and when the decoder receives the trigger event, it updates the detection data in the accumulation buffer to the readout buffer in real time, thereby sending it to the processing unit through the communication interface. This can overcome differences in frame rate, phase, or tracking confidence between multiple optical navigation chips and provide accurate displacement synchronization.

Description

Technical Field

[0001] This invention relates to an optical navigation chip and an optical navigation system thereof, and more particularly to an optical navigation chip and an optical navigation system thereof with a displacement synchronization mechanism. Background Technology

[0002] Optical inspection technology is widely used in various types of products; common optical trajectory tracking devices are used in mouse wheels to detect the rotation and pressing of the wheel. With technological advancements, optical inspection technology can be further integrated with transportation vehicles for trajectory tracking. Mouse wheels are small, and a single optical inspection chip can effectively detect their movement. However, transportation vehicles are large, and if an optical inspection chip is installed only on one side of the vehicle, it is prone to misinterpreting the vehicle's trajectory during turns. Therefore, multiple optical inspection chips need to be installed at different locations on the vehicle to detect the correct trajectory. However, these multiple optical inspection chips have different displacement references, making effective integration during subsequent calculations difficult. Furthermore, if some optical inspection chips malfunction, it can mislead the integration results of multiple chips, affecting the accuracy of the detection. Therefore, designing an optical navigation system with a displacement synchronization mechanism is one of the key development goals of the related optical equipment industry. Summary of the Invention

[0003] This invention relates to an optical navigation chip with a displacement synchronization mechanism and an optical navigation system thereof.

[0004] This invention further discloses an optical navigation chip applied in a computational processor with a displacement synchronization mechanism. The optical navigation chip includes a tracking module, a decoder, a readout buffer, and an accumulation buffer. The tracking module generates detection data. The decoder receives trigger events. The readout buffer is connected to the computational processor via a communication interface. The accumulation buffer connects the tracking module, the decoder, and the readout buffer. The accumulation buffer stores the detection data from the tracking module, and when the decoder receives the trigger event, it immediately updates the readout buffer with the detection data from the accumulation buffer, thereby sending it to the computational processor via the communication interface.

[0005] This invention also discloses an optical navigation system with a displacement synchronization mechanism, including a processing unit, a communication interface, and multiple optical navigation chips. The processing unit is used to output trigger events. The multiple optical navigation chips are electrically connected to the processing unit through the communication interface. Each of the multiple optical navigation chips includes a tracking module, a decoder, a readout buffer, and an accumulation buffer. The tracking module is used to generate detection data. The decoder is used to receive trigger events. The readout buffer is connected to the communication interface. The accumulation buffer is connected to the tracking module, the decoder, and the readout buffer; the accumulation buffer stores the detection data from the tracking module. When the decoder receives the trigger event, the multiple optical navigation chips synchronously update the detection data in their respective accumulation buffers to the corresponding readout buffers, thereby sending them to the processing unit in turn through the communication interface.

[0006] The present invention also discloses that the processing unit can simultaneously electrically connect the multiple optical navigation chips using a one-to-many interface communication interface, or can separately electrically connect the multiple optical navigation chips using a many-to-many interface communication interface.

[0007] The present invention also discloses that when the optical navigation chip receives the trigger event and updates the detection data to the readout buffer, it clears the detection data in the accumulation buffer; the tracking module accumulates the detection data generated during the time period when the decoder does not receive the trigger event, and stores it in the accumulation buffer.

[0008] The present invention also discloses that the detection data is displacement data generated by the tracking module when tracking an object. The processing unit integrates these displacement data from the multiple optical navigation chips to synchronously process the tracking trajectories generated by the multiple optical navigation chips.

[0009] The present invention also discloses that the detection data is the time length or frame number of each frame generated by the tracking module when tracking an object. The processing unit analyzes these time lengths or frame numbers of the plurality of optical navigation chips to compensate for frame rate differences or phase differences between the plurality of optical navigation chips.

[0010] The present invention also discloses that the detection data is the tracking confidence level generated by the tracking module when tracking objects. The processing unit compares the tracking confidence levels of the plurality of optical navigation chips with a predetermined threshold range, and sets the weight ratio among the plurality of optical navigation chips according to the comparison result.

[0011] The present invention also discloses that the optical navigation chip analyzes the feature value matching results between multiple frames generated by the tracking module when tracking the object to convert them into the tracking confidence level; or, the optical navigation chip analyzes the difference between the tracking trajectory and the predicted trajectory generated by the tracking module when tracking the object to calculate the tracking confidence level.

[0012] The optical navigation system of this invention establishes a specially defined communication interface between the processing unit and the optical navigation chip. This interface can selectively use a general-purpose input / output interface to transmit pulse signals or an internal integrated circuit to transmit bus commands. The optical navigation chip may additionally include a decoder and an accumulation buffer. The accumulation buffer stores the detection data of the tracking module before synchronization updates, while the decoder receives trigger events to allow multiple optical navigation chips to use as a reference for synchronously updating the detection data from the accumulation buffer to the readout buffer. The detection data may include displacement data, frame duration and / or frame number, and tracking confidence level. This invention can synchronously lock the displacement data of multiple optical navigation chips and use the frame duration and / or frame number, as well as the tracking confidence level, to compensate for the displacement data. This allows the processing unit to overcome differences in frame rate, phase, or tracking confidence level between multiple optical navigation chips during subsequent integration, providing accurate displacement synchronization.

[0013] At the application level, the optical navigation system of this invention can place multiple optical navigation chips at different locations on a vehicle, such as near the front and rear wheels on the left side of a car, or near the front and rear wheels on the right side of a car. Each optical navigation chip transmits displacement data generated during object tracking to a processing processor. The processing processor integrates this displacement data using a displacement synchronization mechanism to accurately determine the car's forward, backward, or turning movements. It then selectively uses the frame duration and / or frame number, as well as tracking confidence level, to correct the synchronization integration result of the displacement data and delete abnormal frames, thereby further improving the accuracy of the displacement synchronization function. Attached Figure Description

[0014] Figure 1 This is a functional block diagram of an optical navigation system according to an embodiment of the present invention.

[0015] Figure 2 This is a functional block diagram of the optical navigation chip according to an embodiment of the present invention.

[0016] Figure 3 and Figure 4 This is a schematic diagram illustrating the connection relationship between the computing processor and the optical navigation chip in different embodiments of the present invention.

[0017] Figure 5 This is a schematic diagram illustrating the operation of multiple optical navigation chips according to an embodiment of the present invention.

[0018] The reference numerals in the attached figures are explained as follows:

[0019] 10 Optical Navigation System

[0020] 12 Computing Processors

[0021] 14 Communication Interface

[0022] 16 Optical navigation chips

[0023] 18. Tracking Module

[0024] 20 decoders

[0025] 22 Readout Buffer

[0026] 24 Accumulation Buffer Detailed Implementation

[0027] Please see Figure 1 , Figure 1 This is a functional block diagram of the optical navigation system 10 according to an embodiment of the present invention. The optical navigation system 10 has a multi-optical tracking displacement synchronization mechanism and can be applied to various types of transportation vehicles. For example, the optical navigation system 10 can be installed on the chassis of a car, or on the bottom of a robotic vacuum cleaner or drone, to detect road feature points to determine the movement of the car, robotic vacuum cleaner, or drone; the optical navigation system 10 can also be installed near a treadmill track or a production line conveyor belt to detect feature points of the track or conveyor belt to determine its movement. The optical navigation system 10 may include a processing unit 12, a communication interface 14, and optical navigation chips 16. There may be multiple optical navigation chips 16, and they are electrically connected to the processing unit 12 through the communication interface 14. The communication interface 14 can be a general-purpose input / output (GPIO) interface, an inter-integrated circuit (I2C), an improved inter-integrated circuit (I3C), or a serial peripheral interface bus (SPI); however, its application is not limited to these and depends on the design requirements.

[0028] Please see Figure 2 , Figure 2This is a functional block diagram of the optical navigation chip 16 according to an embodiment of the present invention. The optical navigation chip 16 may include a tracking module 18, a decoder 20, a readout buffer 22, and an accumulation buffer 24. The tracking module 18 uses trajectory tracking technology to acquire detection data; the detection data can be converted and used to determine the forward, backward, or turning behavior of the vehicle or other equipment to which the optical navigation system 10 is applied. The decoder 20 is used to receive and parse the trigger events output by the processing processor 12 to obtain the required information. The processing processor 12 may automatically output trigger events under certain circumstances, or receive manual commands from the user and output trigger events accordingly; the variation depends on the design requirements.

[0029] The readout buffer 22 can be connected to the communication interface 14. The accumulation buffer 24 is located between the tracking module 18, the decoder 20, and the readout buffer 22, and is used to store the detection data from the tracking module 18. When the optical navigation chip 16 starts operating, the tracking module 18 continuously generates detection data; during the time period when the optical navigation chip 16 does not receive a trigger event, the detection data generated by the tracking module 18 is accumulated and stored in the accumulation buffer 24. If the processing processor 12 issues a trigger event, causing multiple optical navigation chips 16 to receive the trigger event, each optical navigation chip 16 will synchronously update the detection data stored in its respective accumulation buffer 24 to the readout buffer 22, and then the multiple optical navigation chips 16 will send the detection data in their respective readout buffers 22 to the processing processor 12 in turn through the communication interface 14; at this time, after the optical navigation chip 16 updates the detection data in the accumulation buffer 24 to the readout buffer 22, it will clear the detection data in the accumulation buffer 24.

[0030] Please see Figure 3 and Figure 4 , Figure 3 and Figure 4 This diagram illustrates the connection between the processing processor 12 and the optical navigation chip 16 in different embodiments of the present invention. The optical navigation system 10 of the present invention incorporates a communication interface 14 between the processing processor 12 and the optical navigation chip 16, capable of transmitting trigger events. Depending on the communication interface 14, it can be a general-purpose input / output interface or a variation of an internal integrated circuit. The trigger event may be in the form of a pulse signal or a bus command. Furthermore, the processing processor 12 can selectively utilize a one-to-many interface communication interface 14 (e.g., a general-purpose input / output interface and an internal integrated circuit) to simultaneously electrically connect multiple optical navigation chips 16, such as... Figure 3 As shown, or by using a many-to-many communication interface 14 (e.g., a serial peripheral interface) to electrically connect multiple optical navigation chips 16 respectively, such as Figure 4 As shown; its variation depends on design requirements.

[0031] Please see Figure 5 , Figure 5 This is a schematic diagram illustrating the operation of multiple optical navigation chips 16 according to an embodiment of the present invention. Figure 5 Taking two optical navigation chips 16 as an example, however, practical applications are not limited to this. For example... Figure 5 As shown, the upper optical navigation chip 16 has a higher frame rate, and the lower optical navigation chip 16 has a lower frame rate. If the optical navigation system 10 does not have a displacement synchronization mechanism for multiple optical tracking, it may read the detection data of the upper optical navigation chip 16 every N frames (e.g., N=5) and the detection data of the lower optical navigation chip 16 every M frames (e.g., M=2). Due to the different frame rates, the start and end points of the frames from different optical navigation chips 16 will have errors, making integration difficult.

[0032] In a preferred embodiment of the present invention, the detection data may include displacement data generated by the tracking module 18 when tracking an object, and the displacement data of different optical navigation chips 16 usually have different displacement start and end points. Therefore, the optical navigation system 10 of the present invention has a displacement synchronization mechanism for multiple optical tracking, which can first store the detection data generated by the tracking modules 18 of multiple optical navigation chips 16 in the accumulation buffer 24, and then synchronously update the readout buffer 22 after the decoder 20 receives a trigger event so that it can be sent to the processing processor 12 in turn; such as Figure 5 The second trigger event shown will synchronize and integrate the fifth frame of the upper optical navigation chip 16 and the second frame of the lower optical navigation chip 16. In this way, the processing unit 12 can integrate the displacement data of multiple optical navigation chips 16 and synchronize the tracking trajectories generated by different optical navigation chips 16 to achieve displacement synchronization.

[0033] Furthermore, multiple optical navigation chips 16 may have different frame rates or phase differences, such as Figure 5 The second trigger event shown still has a time difference compared to frame 5 of the upper optical navigation chip 16 and frame 2 of the lower optical navigation chip 16. Therefore, the present invention further defines the detection data as including the time length or number of frames generated by the tracking module 18 when tracking the object. As multiple optical navigation chips 16 receive the trigger event and synchronously update the detection data to the readout buffer 22 to send it to the processing processor 12 in turn, the processing processor 12 can analyze the time length and / or number of frames of each of the multiple optical navigation chips 16, and compensate for the frame rate difference or phase difference between the multiple optical navigation chips 16 based on the analysis results, that is, compensate for the time difference of the aforementioned different frames, and further optimize its displacement synchronization function.

[0034] Furthermore, the detection data of the present invention may also include the tracking confidence level generated by the tracking module 18 when tracking the object. The tracking confidence level can be the difference between the tracking trajectory and the predicted trajectory generated during object tracking. For example, the historical trajectory may be an arc from left to right, so the predicted trajectory is usually also an arc from left to right; if the detected tracking trajectory is a straight line from left to right, it indicates that the trajectory is abnormal. At this time, the difference between the tracking trajectory and the predicted trajectory can be converted into the tracking confidence level. The difference result and the tracking confidence level are preferably inversely proportional, that is, the smaller the difference result, the higher the tracking confidence level. Detection data with high tracking confidence level is retained, while detection data with low tracking confidence level has its weight reduced or is directly discarded to avoid the final displacement detection result of the optical navigation system 10 being affected by abnormal trajectories and becoming inaccurate.

[0035] Alternatively, tracking confidence can also be the feature value matching result between multiple frames generated during object tracking. For example, object tracking generates at least a previous frame and a subsequent frame. Multiple feature points in the previous frame can form a first cluster, and multiple feature points in the subsequent frame can form a second cluster. If a few feature points have different distribution parameters in the first cluster than in the second cluster, the matching result can be calculated based on the distribution ratio of the feature points in different clusters across different frames, and then further converted into tracking confidence. Generally, the higher the similarity of the distribution of corresponding clusters of feature points in different frames, the higher the tracking confidence derived from the matching result. The calculation method for tracking confidence is not limited to the above implementation and depends on the design requirements.

[0036] The optical navigation system 10 compares the tracking confidence levels of multiple optical navigation chips 16 to a predetermined threshold range. The actual value of the predetermined threshold range depends on the accuracy of the optical navigation chips 16 and the computational performance of the processor 12, and therefore will not be detailed here. If the tracking confidence level of one optical navigation chip 16 is higher than the predetermined threshold range, the detection data obtained by this optical navigation chip 16 will have a higher weight; if the tracking confidence level of another optical navigation chip 16 is within the predetermined threshold range, the detection data obtained by this optical navigation chip 16 will have a lower weight; if the tracking confidence level of other optical navigation chips 16 is lower than the predetermined threshold range, the detection data obtained by this optical navigation chip 16 can be discarded. In this way, the optical navigation system 10 can set weight ratios among multiple optical navigation chips 16 and use these weight ratios to determine the reliability of the detection data obtained by the multiple optical navigation chips 16, thereby deciding whether an optical navigation chip 16 has experienced a detection anomaly and accordingly adopting or discarding its detection data.

[0037] In summary, the optical navigation system of this invention establishes a specially defined communication interface between the processing unit and the optical navigation chip. This communication interface can selectively use a general-purpose input / output interface to transmit pulse signals or an internal integrated circuit to transmit bus commands. The optical navigation chip can additionally include a decoder and an accumulation buffer. The accumulation buffer stores the detection data of the tracking module before synchronization updates, while the decoder receives trigger events to allow multiple optical navigation chips to use as a reference for synchronously updating the detection data from the accumulation buffer to the readout buffer. The detection data may include displacement data, frame duration and / or frame number, and tracking confidence level. This invention can synchronously lock the displacement data of multiple optical navigation chips and use the frame duration and / or frame number, as well as the tracking confidence level, to compensate for the displacement data. This allows the processing unit to overcome differences in frame rate, phase, or tracking confidence level between multiple optical navigation chips during subsequent integration, providing accurate displacement synchronization.

[0038] At the application level, the optical navigation system of this invention can place multiple optical navigation chips at different locations on a vehicle, such as near the front and rear wheels on the left side of a car, or near the front and rear wheels on the right side of a car. Each optical navigation chip transmits displacement data generated during object tracking to a processing processor. The processing processor integrates this displacement data using a displacement synchronization mechanism to accurately determine the car's forward, backward, or turning movements. It then selectively uses the frame duration and / or frame number, as well as tracking confidence level, to correct the synchronization integration result of the displacement data and delete abnormal frames, thereby further improving the accuracy of the displacement synchronization function.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optical navigation chip, used in a computational processor with a displacement synchronization mechanism, characterized in that, The optical navigation chip includes: The tracking module is used to generate detection data; The decoder is used to receive trigger events; The read buffer is connected to the processing processor via a communication interface; and The accumulation buffer connects the tracking module, the decoder, and the readout buffer. The accumulation buffer stores the detection data from the tracking module, and when the decoder receives the trigger event, it immediately updates the detection data in the accumulation buffer to the readout buffer, thereby sending it to the processing processor through the communication interface.

2. The optical navigation chip as described in claim 1, characterized in that, When the optical navigation chip receives the trigger event and updates the detection data to the readout buffer, it clears the detection data in the accumulated buffer.

3. The optical navigation chip as described in claim 1, characterized in that, The tracking module accumulates the detection data generated during the time period when the decoder does not receive the trigger event, and stores it in the accumulation buffer.

4. The optical navigation chip as described in claim 1, characterized in that, The detection data is the displacement data generated by the tracking module when tracking objects.

5. The optical navigation chip as described in claim 1, characterized in that, The detection data refers to the time length or number of frames generated by the tracking module when tracking objects.

6. The optical navigation chip as described in claim 1, characterized in that, This detection data represents the tracking confidence level generated by the tracking module when tracking objects.

7. The optical navigation chip as described in claim 6, characterized in that, The optical navigation chip analyzes the feature value matching results between multiple frames generated by the tracking module when tracking the object, and converts them into tracking confidence.

8. The optical navigation chip as described in claim 6, characterized in that, The optical navigation chip analyzes the difference between the tracking trajectory and the predicted trajectory generated by the tracking module when tracking the object to calculate the tracking confidence level.

9. An optical navigation system with a displacement synchronization mechanism, characterized in that, The optical navigation system includes: The processing unit is used to output trigger events; Communication interface; and Multiple optical navigation chips are electrically connected to the processing unit via the communication interface. Each of the multiple optical navigation chips includes: The tracking module is used to generate detection data; A decoder is used to receive the triggering event; Read the buffer and connect to the communication interface; and An accumulation buffer connects the tracking module, the decoder, and the readout buffer. The accumulation buffer stores the detection data from the tracking module. When the decoder receives the trigger event, the multiple optical navigation chips synchronously update the detection data in their respective accumulation buffers to the corresponding readout buffers, and then send them to the processing processor in turn through the communication interface.

10. The optical navigation system as described in claim 9, characterized in that, The processor can simultaneously connect to the multiple optical navigation chips using a one-to-many interface, or separately connect to the multiple optical navigation chips using a many-to-many interface.

11. The optical navigation system as described in claim 9, characterized in that, When the optical navigation chip receives the trigger event and updates the detection data to the readout buffer, it clears the detection data in the accumulated buffer.

12. The optical navigation system as described in claim 9, characterized in that, The tracking module accumulates the detection data generated during the time period when the decoder does not receive the trigger event, and stores it in the accumulation buffer.

13. The optical navigation system as described in claim 9, characterized in that, The detection data is the displacement data generated by the tracking module when tracking objects.

14. The optical navigation system as described in claim 13, characterized in that, The processor integrates the displacement data of the multiple optical navigation chips to synchronize the tracking trajectories generated by each of the multiple optical navigation chips.

15. The optical navigation system as described in claim 9, characterized in that, The detection data refers to the time length or number of frames generated by the tracking module when tracking objects.

16. The optical navigation system as described in claim 15, characterized in that, The processor analyzes the time lengths or frame numbers of the plurality of optical navigation chips to compensate for frame rate or phase differences between the plurality of optical navigation chips.

17. The optical navigation system as described in claim 9, characterized in that, This detection data represents the tracking confidence level generated by the tracking module when tracking objects.

18. The optical navigation system as claimed in claim 17, characterized in that, The processor compares the tracking confidence levels of the multiple optical navigation chips to a predetermined threshold range and sets the weight ratio among the multiple optical navigation chips based on the comparison results.

19. The optical navigation system as described in claim 17, characterized in that, The optical navigation chip analyzes the feature value matching results between multiple frames generated by the tracking module when tracking the object, and converts them into tracking confidence.

20. The optical navigation system as claimed in claim 17, characterized in that, The optical navigation chip analyzes the difference between the tracking trajectory and the predicted trajectory generated by the tracking module when tracking the object to calculate the tracking confidence level.

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