What Is a Positioner?

It is installed on the relocation platform of the dumper or the railway track to brake the slow-moving wagon and park it at a predetermined position.

Case

The old mother of Mr. Chen who lives in Jiangning District, Nanjing

There are many kinds of locators, the known types are: slot machine locator

Positioner is the main accessory of regulating valve, usually with pneumatic

(1) It is used for important regulating systems with high requirements on regulating quality to improve the positioning accuracy and reliability of regulating valves.

(2) For applications where the pressure difference across the valve is large ( p> 1MPa). By increasing the pressure of the air source, the output force of the actuator is increased to overcome the unbalanced force generated by the liquid on the valve core and reduce the stroke error.

(3) When the medium to be adjusted is high temperature, high pressure, low temperature, toxic, flammable, and explosive, in order to prevent external leakage, the packing is often pressed tightly, so the friction between the valve stem and the packing is large. Use the positioner to overcome the time lag.

(4) When the medium to be adjusted is a viscous fluid or contains solid suspended matter, the positioner can overcome the resistance of the medium to the valve stem.

(5) For large-diameter (Dg> 100mm) regulating valve to increase the output thrust of the actuator.

(6) When the distance between the regulator and the actuator is more than 60m, the positioner can overcome the transmission delay of the control signal and improve the response speed of the valve.

(7) Used to improve the flow characteristics of the control valve.

(8) When one actuator controls two actuators to implement split-range control, two positioners can be used to accept low input signals and high input signals respectively. Then one actuator moves at a low level and the other moves at an high level, which constitutes Process adjustment.

Implied conditions,

There are two types of mobile phone positioning technologies, one is GPS-based positioning, and the other is base station positioning based on mobile operating networks.

The GPS-based positioning method uses a GPS positioning module on a mobile phone to receive signals from GPS satellites, and uses these signals for navigation and positioning.

Base station positioning uses the base station's measured distance to determine the phone's location. The latter does not require the mobile phone to have GPS positioning capability, but the accuracy depends to a large extent on the distribution of the base stations and the size of the coverage, and sometimes the error will exceed one kilometer. The former has higher positioning accuracy. There is also a way to use Wifi to locate in a small area.

With regard to the accuracy of GPS system positioning, user expectations continue to rise. Today's users not only want to be able to take advantage of the satellite's clear line of sight (LOS) to increase navigation accuracy in traditional "GPS-friendly" environments, but also in "non-GPS-friendly" environments like garages and tunnels. This means faster time to first fix (TTFF), greater reliability, and more general availability.

Therefore, in the field of after-installation, coupling sensors are more used, such as gyroscopes and accelerometers. In the front-loading market, dead reckoning systems are used more. The dead reckoning system is connected to the existing system through the car data bus, such as odometers, single-wheel speed information and other sensing measures used to determine speed and direction.

The advantage of GPS devices using car data systems is that they do not need to use those expensive sensors, but rather use car data easily. If the GPS system can make good use of car components, whether it is the single-wheel speed sensor in the auxiliary brake system (ABS, the standard of most American and European cars), the stability control system (more commonly used in Europe), or ^1]

Metal locator detection system includes: Walloon metal locator, MC1 microcomputer, a rucksack (with GPS inside the antenna), and a GPS information receiving station. Walloon analysis and evaluation software is installed in the laptop. The complete set of equipment is simple to assemble and the operator can operate the system with very little training time. The MC1 microcomputer (installed on the positioner) traces the measured magnetic flux values in real time in the form of a curve.

GPS positioning information is refreshed every second. The operator can analyze any target that is suspected to be unexploded. The system can also print all target lists and 1: 1 topographic maps for subsequent troops in units of meters or feet. Both the target list and the topographic map reflect the area, and its longitude and latitude are pinpointed by the global positioning system.

Valve positioner is divided into pneumatic valve positioner, electric valve positioner and intelligent valve positioner according to the input signal. The input signal of a pneumatic valve positioner is a standard gas signal, for example, a 20 ~ 100kPa gas signal, and its output signal is also a standard gas signal. The input signal of the electric valve positioner is a standard current or voltage signal, for example, 4 ~ 20mA current signal or 1 ~ 5V voltage signal. Control valve. The intelligent electric valve positioner converts the current signal output from the control room into the air signal that drives the regulating valve. Based on the friction of the valve stem when the regulating valve is working, it can offset the unbalanced force caused by the pressure fluctuation of the medium, so that the valve opening corresponds to the control Room output current signal. And the intelligent configuration can be set to set the corresponding parameters to achieve the purpose of improving the performance of the control valve.

1. According to the direction of action, it can be divided into one-way valve positioner and two-way valve positioner. When the one-way valve positioner is used in a piston actuator, the valve positioner works in only one direction, and the two-way valve positioner works on both sides of the piston actuator cylinder, and works in two directions.

2. According to the gain symbols of valve positioner output and input signal, it is divided into positive-acting valve positioner and negative-acting valve positioner. When the input signal of the positive-acting valve positioner increases, the output signal also increases, so the gain is positive. When the input signal of the reaction valve positioner increases, the output signal decreases, so the gain is negative.

3, according to the valve positioner input signal is analog or digital signal, can be divided into ordinary valve positioner and field bus electrical valve positioner. The input signal of a common valve positioner is an analog pressure or current, voltage signal, and the input signal of a fieldbus electrical valve positioner is a digital signal of a fieldbus.

4, according to whether the valve positioner with CPU can be divided into ordinary electrical valve positioner and intelligent electrical valve positioner. Ordinary electrical valve positioners do not have a CPU, so they do not have intelligence and cannot handle related intelligent calculations. The intelligent electric valve positioner with a CPU can process related intelligent calculations, for example, it can perform non-linear compensation of forward channels, etc. The fieldbus electric valve positioner can also carry functional modules such as PID to achieve corresponding operations. ^[2]