Application of the hottest polar coordinate method

Application of polar coordinate method in equipment installation engineering

in large industrial buildings and installation projects, rectangular control has been generally used as construction measurement control for many years, and according to this, plant positioning, plant column alignment, and detailed setting out of equipment foundation are carried out. And use this control to lay several corresponding elevated central line boards for foundation construction. Sometimes, a main axis is also measured according to the process production center line of the design and construction drawing, and the center lines of several main equipment are added on the main axis as the "cross" vertical line to form the main axis control system

in the construction survey of the equipment installation project of Jigang (Malaysia) steel plate Co., Ltd., most of the equipment foundation has been completed, the original construction control points no longer exist, and some equipment has been basically in place. If the rectangular control is re measured, it is impossible. In order to make the equipment installation meet the requirements of the specification, after the detailed investigation and measurement of the completed equipment foundation, according to the measured data of the center line of the existing equipment foundation and the center line points of the embedded large foundation bolts of the key equipment (such as the three high rolling mill, the three high rolling mill connecting machine, the three high rolling mill main motor, the four high rolling mill, the upper and lower main motors of the four high rolling mill, etc.), according to the design requirements of the general layout drawing of the production process design, Under the condition of meeting the requirements of production process and equipment installation specifications, the errors in the civil construction of equipment foundation are allocated reasonably, and it is decided to design and measure the main axis system as the control system for the construction measurement of equipment installation engineering (see Figure 1). 1 - center line of lower motor; 2 - center line of upper motor; 3 - center line of three roll main motor; 4 - reducer center line; 5 - center line of connecting machine

6 - center line of three high mill train; 7-4-high rolling mill train center line

Figure 1 main axis system schematic diagram because the equipment has been basically in place, it is impossible or difficult to erect the instrument firmly on the center line, and it is more difficult to detect the accuracy of equipment installation in place. If the center line point on the main axis is detected by the hanging ball line plus micrometer or steel ruler, many errors will be generated, such as the line erection board throwing point, marking, line erection board vibration, line hanging deviation, vertical point deviation, measurement error, etc. it is very difficult to achieve the installation standard of high-precision Haier to explore the innovative mode of interconnected factories. After research and analysis, it is decided to adopt polar coordinate method for measurement

the difference between the polar coordinate method and the rectangular control method and the main axis method is that it is not necessary to set up a station (set up instruments) on the center line point to carry out the construction setting out and the inspection and retest after the equipment is in place. This method can directly measure the measuring point at any observable position, calculate the coordinate value of the measuring point by using the polar diameter and polar angle (distance, coordinate azimuth), and compare the measured value with the design value, that is, the deviation value must be calculated from the surface to the center for correction or confirmation. 1. Main steps of polar coordinate method (1) according to the design and construction drawings, design the rectangular control diagram or the main axis control system diagram according to the actual needs, and mark the control points

(2) all the control points of the above design are substituted into a coordinate system, and the coordinate values are marked. The coordinate system can be replaced by the construction drawing coordinate system or the assumed coordinate system, based on the principle of convenient calculation and annotation. The main axis of the coordinate system takes the center line and point of the main equipment of the production process line as the coordinate axis and coordinate origin

(3) according to the coordinate axis, coordinate origin and the dimensions required by the process design on the design drawing, the vertical and horizontal coordinate values (x, y) on the centerline of each relevant main equipment or equipment foundation can be calculated. A set of hypothetical coordinate system can also be designed according to the main process line of the production equipment. Taking the center line of the equipment on the main process line as the "origin and baseline" of the "cross" coordinate axis, the coordinate values of the remaining equipment and related dimensions can be calculated according to the design process dimensions. And substitute the corresponding X and Y values respectively

(4) try to avoid the construction area, construction foundation and production process line, select several points, make the selected point spacing roughly equal, and form a tight closed wire after connecting. The selected point must be stable and not easy to touch

(5) measure, calculate and adjust the selected point line. The results after adjustment should be higher than the relevant provisions of section III of Chapter II and Section IV of Chapter III of code for construction survey of Metallurgical Building Engineering (ybj212-88). It is not difficult to measure with total station

(6) after strict verification with rectangular control or main axis, the results of point selection shall be sorted into a volume and archived for future use

(7) in order to prevent confusion in the recording and use of vertical and horizontal coordinates when selecting points, and to facilitate future use and recording, the values of vertical and horizontal coordinates can be distinguished by different digits. For example, the x value is set with 4 digits before the decimal point, and the y value is set with 5 digits before the decimal point (here it can be determined according to the size of the construction survey control range), and the digits (value) after the decimal point can be designed according to actual needs. 2. Examples of polar coordinate measurement take Jigang (Malaysia) steel plate Co., Ltd. four high rolling mill, four high rolling mill traverse pull-out roll change device, four high rolling mill main motor upper position. Why do some tensile testing machines sell at a very low price? Next, the Ligao detection equipment will take you to analyze this problem. Take the installation detection of the lower motor as an example (see Figure 2). Note: the coordinate marking unit is m

Figure 2 equipment installation detection schematic station B point, x=850.0000, y=1362.0000

rear view a point α Ba=180 ° 00 ′ 00 ″

check the center of four high mill x=843.2500, y=1344.0000

point B of the measuring station to the center of four high mill α= 249 ° 26 ′ 38.2 ″

after checking and verifying the calibration direction, the points on the center line of the equipment can be measured, as shown in Figure 2, D1, D3, D5, D7 on the horizontal center line and D2, D4, D6, D8 on the longitudinal center line, which can carry out independent control and combined control in any way in four directions for four actuators. The center point on the equipment body can also be measured directly

when measured D1, xd1=xb+s α Bd1,Yd1=YB+n αΒ BD1 (Note: XD1 is the ordinate of point D1, yd1 is the abscissa of point D1, and dbd1 is the abscissa of point B to point D1 of the station