Valve lift measuring system

Abstract

Valve lift measuring system (1) which enables the valve lift amount of internal combustion engines to be measured with respect to time by evaluating digital images received from the high-speed camera in the valve train test mechanism, comprising valves on an internal combustion engine, characterized in that the valve lift measuring system (1) further comprises - at least one test mechanism (2) which enables the valves in the internal combustion engine to be operated independently of the engine, - wherein at least one of the valves is a test valve (3) whose valve lift amount is to be measured in the test mechanism (2) and which is marked so as to be distinguished from the objects and parts around it, and wherein there is a black and white marking on the test valve (3), - at least one reference valve (4), the valve lift amount of which is measured in the test mechanism (2), which is marked in the test mechanism (2) with a different marking, - at least one camera (5) mounted at right angles to the valves moving in the test mechanism (2), - at least one control unit (6) configured to calculate the stroke amount of the test valve (3) with respect to time by calculating the locations of the markings on the test valve (3) and the reference valve (4) and their locations relative to one another, and wherein the control unit (6) is configured to calculate the movement amount of the test valve (3) with respect to the reference valve (4) by calculating the location of the marking 1 (A) on the test valve (3) with respect to the location of the marking 2 (B) on the reference valve (4), and wherein the control unit (6) is configured to calculate the location of the marking 1 (A) attached to the test valve (3) in the image using a statistical method using the following equation: C ( k , l ) = ∑ m = 0 M − 1 ∑ n = 0 N − 1

Description

Field of the invention

[0001] The present invention relates to a system that measures the valve lift amount with respect to time by evaluating high-speed camera images in the valve train test mechanism. Background of the invention

[0002] The measurement of the valve's opening-closing stroke is performed using sensors specifically manufactured for the measurement. These sensors are instrumented at suitable locations on the valve, and the measurement is performed using digital measuring systems specifically manufactured for the sensors. Instrumenting the sensors required for valve stroke measurement at suitable locations requires additional operations on the parts. These operations cause a change in the geometry and mass of the part and alter the dynamic behavior of the valve. As a result of the system's instrumentation and the operations on the parts, error-free operation of the measuring system cannot be guaranteed; error-free operation of the system is achieved through a trial-and-error process. This trial-and-error process results in part, time, and labor losses.

[0003] US Patent Document No. US 5 056 046 A, an application known in the prior art, discloses a system that allows data to be acquired from pneumatic valves. The system includes a camera that allows an image to be received from the valves. This system also includes a marker for use in calculating the valve displacement. As the valve transitions between the fully open and fully closed positions, images are received from the valve, and these images are evaluated. The control of the valve openness is determined by evaluating the lines in analog video signals to determine whether the markers on the valve control rod are covered or uncovered during actuator movement.

[0004] Japanese Patent Document No. JP 2010-85105 A, an application known in the prior art, discloses a device for monitoring and diagnosing the condition of motor-driven valves. The system includes a camera that enables an image of the valves to be received. The system also includes a marker. The system further includes an image evaluation system for evaluating the images received from the cameras and measuring the time and load on the shaft. The images received by the image evaluation unit are evaluated by a data analysis device. For these operations, a camera capable of receiving images at high speed is not used; the measurements are performed by capturing two images. These measurements are performed using more than two markers.

[0005] From European patent document No. EP 0 275 229 A1 a method and a device for automatically detecting the position of stationary or moving shapes or shadows by means of a video camera is known.

[0006] A valve position sensor which can determine the stroke and rotation of the valve is known from CN 201 818 889 U.

[0007] From JP H08-219 324 A a device is known which can detect the open and closed state of a valve in a pipeline.

[0008] From US patent document No. US 2013 / 0 155 227 A1, a valve control system for a pipeline is known, wherein a metallic pin is connected to the valve stem and this is detected by means of a camera.

[0009] From JP H11-190 269 A a method and a device for installing spark plugs is known.

[0010] DE 26 33 166 B1 discloses an additional device for a television system for electronic image evaluation.

[0011] US 5 673 331 A discloses a method and a device for capturing analogue measuring instruments that do not have a data interface by means of a camera. Summary of the invention

[0012] It is the object of the present invention to provide a system that enables the valve lift amounts of internal combustion engines to be measured according to time by evaluating high-speed camera images in the valve train testing mechanism.

[0013] This object is achieved according to the invention with an article according to the features of claim 1.

[0014] In one embodiment, the valve lift measurement system is based on calculating the location of a marker arranged on the valve, which has a high contrast with the objects around it, on the digital image using two-dimensional digital statistical methods in the digital video image received from the high-speed camera. The calculation process is carried out using a computer. Therefore, the location of the marker, which moves with the valve, is calculated in each frame of the video, and each movement of the valve is measured in each video frame. The imaging speed of the high-speed camera can be set to 1000-5000 frames per second. The movement of a valve can be up to a maximum of 250 movements per second. Therefore, the time elapsed between two frames is calculated, and the valve movement is measured with respect to time.

[0015] Because image analysis and valve lift measurement do not require any valve train surgery, the geometry and mass of the system are not altered. Therefore, the dynamic behavior of the system remains unchanged. Because there is no mechanical instrumentation, the potential for error in the measurement system is minimized, as are potential component, time, and labor losses due to trial and error. Detailed description of the invention

[0016] A valve lift measuring system which has been developed to achieve the object of the present invention is illustrated in the accompanying figures, wherein: Fig. 1 is a schematic view of the valve lift measuring system; Fig. 2 is a view of a reference measurement on the test valve; and Fig. Figure 3 is a schematic view showing the movements of the test valve and the reference valve within the test mechanism.

[0017] Each of the components shown in the figures is given reference numerals as follows: 1. Valve lift measuring system 2. Test mechanism 3. Test valve 4. Reference valve 5. Camera 6. Control unit A. Mark 1 B. Marking 2 X. Reference measurement

[0018] A valve lift measuring system (1) which enables the valve lift amount of internal combustion engines to be measured with respect to time by evaluating digital images received from the high-speed camera in the valve train testing mechanism, essentially comprises - at least one test mechanism (2) which enables the valve in the internal combustion engines to be operated independently of the engine, - at least one test valve (3) whose valve lift amount is to be measured in the test mechanism (2) and which is marked so that it can be distinguished from the objects and parts around it, - at least one reference valve (4) marked with a different marking in the test mechanism (2), - at least one camera (5), which is preferably mounted at a right angle to the valves moving in the test mechanism (2), - at least one control unit (6) arranged to calculate the stroke amount of the test valve (3) with respect to time by calculating the locations of the markings on the test valve (3) and the reference valve (4) and their locations with respect to each other.

[0019] In one embodiment of the valve lift measuring system (1), the valves of the internal combustion engines are arranged on a test mechanism (2). The test mechanism (2) enables the valves to operate independently of the engine. A marker is applied to the test valve (3), one of the valves on which the measurement is performed, so that it can be distinguished from the objects and parts around it (has a high contrast). In one embodiment of the invention, a black-and-white marker is used for the marker. A second marker is applied to the reference valve (4), whose valve lift amount is being measured, with a high black-and-white contrast in a different mark from the test valve (3). A camera (5) is then mounted perpendicular to the valves moving in the test mechanism (2), and its position is adjusted so that the valve movements remain within the imaging range ( Fig.1). After a suitable lighting system has been positioned for the test, digital moving images of the valve's movements are recorded via the camera (5) prior to the test. The recorded image is transmitted to a control unit (6), which is preferably a computer, where it is calculated how many mm (millimeters) a pixel image corresponds to with respect to the reference measurement (X). Therefore, the position measurement accuracy is also calculated. In one embodiment of the invention, the reference measurement (X) is; X=2.98 mm±0.02=23 pixels. 1 pixel = 0.13 mm.

[0020] When the test mechanism (2) reaches the rotational speed point of the valves to be tested, the image acquisition process is started via the camera (5), and the received digital image is transmitted to the control unit (6) and recorded there. Using a statistical method, the location of Mark-1 (A), which is a mark applied to the test valve (3), is first calculated in the recorded digital image using an image processing program loaded into the control unit (6).

[0021] In a preferred embodiment of the invention, a two-dimensional correlation method is used to calculate the statistical method. The digital images comprise three matrices according to the RGB standard for digital images (RGB = Red, Green, Blue), with the matrix size indicating the resolution of the digital image. For example, a digital image with a resolution of 800 × 600 comprises three matrices with an (RGB) size of [800 × 600].

[0022] The image of the moving object in this image is a matrix with a smaller size within the matrix. The matrix location of the image created by the moving object can be calculated in the entire image using the two-dimensional correlation method. Therefore, in the video consisting of the digital images, the location of the moving object in each frame can be measured. The following equation is used for the measurement: C(k, l)=∑m=0M−1∑n=0N−1X(m, n) H¯(m−k, n−l)−(P−1)≤k≤M−1,−(Q−1)≤l≤N−1, X: image matrix with a size of M × N, H: image matrix of the object moving in a size of P × Q (mark 1), C: matrix generated as a result of the calculation (size M + P - 1 × N + Q - 1).

[0023] The row and column numbers where the maximum value of the calculated matrix C is present express the location of the moving object being searched for in the image. The amount of movement is calculated based on the change in the location values ​​calculated for each frame. A change of 1 pixel location is calculated based on the reference measurement (X) (in the above example, 1 pixel = 0.13 mm).

[0024] After calculating the location of Mark 1 (A) using the equation given above, the location of Mark 2 (B) attached to the reference valve (4) is also calculated using the same statistical method in the image. Then, according to the location of Mark 2 (B) on the reference valve (4), the location of Mark 1 (A) on the test valve (3) is calculated, and the movement amount of the test valve (3) with respect to a reference point (4) is calculated. C(k, l)=∑m=0M−1∑n=0N−1X(m, n) H¯(m−k, n−l)−(P−1)≤k≤M−1,−(Q−1)≤l≤N−1,

[0025] The valve location is extracted from the reference point, and the calculation is performed using the formula mentioned above.

Claims

[1] Valve lift measuring system (1) which enables the valve lift amount of internal combustion engines to be measured with respect to time by evaluating digital images received from the high-speed camera in the valve train testing mechanism comprising valves on an internal combustion engine, characterized by that the valve lift measuring system (1) further comprises - at least one test mechanism (2) which enables the valves in the internal combustion engine to be operated independently of the engine, - wherein at least one of the valves is a test valve (3) whose valve lift amount is to be measured in the test mechanism (2) and which is marked so as to be distinguished from the objects and parts around it, and wherein there is a black and white marking on the test valve (3), - at least one reference valve (4), the valve lift amount of which is measured in the test mechanism (2), which is marked in the test mechanism (2) with a different marking, - at least one camera (5) mounted at right angles to the valves moving in the test mechanism (2), - at least one control unit (6) configured to calculate the stroke amount of the test valve (3) with respect to time by calculating the locations of the markings on the test valve (3) and the reference valve (4) and their locations relative to one another, and wherein the control unit (6) is configured to calculate the movement amount of the test valve (3) with respect to the reference valve (4) by calculating the location of the marking 1 (A) on the test valve (3) with respect to the location of the marking 2 (B) on the reference valve (4), and wherein the control unit (6) is configured to calculate the location of the marking 1 (A) attached to the test valve (3) in the image using a statistical method using the following equation: C(k, l)=∑m=0M−1∑n=0N−1X(m, n) H¯(m−k, n−l)−(P−1)≤k≤M−1,−(Q−1)≤l≤N−1. [2] Valve lift measuring system (1) according to claim 1, characterized bythe control unit (6) which is designed to record the digital image received via the camera (5). [3] Valve lift measuring system (1) according to claim 1, characterized by the control unit (6) arranged to calculate the location of the mark-2 (B) attached to the reference valve (4) in the image using a statistical method.

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