Peter, can you tell me in detail, why valves should be mounted on the top of the cylinder? How affect trapped volume of oil on operation of control system?
Oil must be compressed to increase the pressure and the resulting force and acceleration. The more oil between the valve and the piston the harder it is to increase or decrease the pressure. Think of the oil like a spring. The longer the spring the more springy it will be and the harder it will be to accurately control a mass on the end of the spring. Look through all the data for natural frequency.
During treatment, log will become crooked. It causes by internal force. Therefore 2 support point is insufficient. It require support point in centre log lenght.
OK, I see. You are holding the log. I was thinking that the axes move the band saws. Normally this is a left and right band saw. Mills that cut bigger logs have two left and two right vertical band saws.
I am from Russia. There are many books about control system, but all books describe only theory. I have very inportent question: how to pass from theory to practice?
With practice! Getting training will be a big help. I can't imagine putting a system together without any help. We I am there is sort of an apprenticeship that engineers go through before being turned loose on their own. I provide training for many of the saw mill OEMs and but am in the Pacific NorthWest in the US. Northwest US and Canada have lots of sawmills and system integrators to keep them going. If you need a system integrator then let me know but you have to be serious about it.
In the US and Canada the standard saw mill PLC is the Rockwell Control Logix 5000. There are two main motion controllers used. The Rockwell M02AS and the Delta Computer Systems, RMC100. Most use the RMC100. There is a new RMC150 but most of the system integrators are just starting to use the newer controller.
These modern controller have auto tuning and will interface directly to Balluff or Temposonic MDT rods. Temposonic MDT rods are standard too with Balluff a distant second. Both the M02AS and the RMCs output +/- 10 volts to drive the valve. The motion commands are relatively simple. A move command consist of a position, velocity, acceleration, deceleration. The motion controller uses this information to generate a motion profile. If you issue the same motion profile to two or more axes at the same time then all of the axes will move together. Each axis will follow its own target but all the targets will be the same. The target position get updated every millisecond or faster. The PID compares the actual position from the MDT feedback with the target position. If the PID and feed forwards are tuned correctly then the actual position will always be very close to the target positions.
After you get the system scaled and the limits set you tune or auto tune the system. Then you try issuing a command with the position velocity and acceleration.
Peter, can you tell me in detail, why valves should be mounted on the top of the cylinder? How affect trapped volume of oil on operation of control system?
Oil must be compressed to increase the pressure and the resulting force and acceleration. The more oil between the valve and the piston the harder it is to increase or decrease the pressure. Think of the oil like a spring. The longer the spring the more springy it will be and the harder it will be to accurately control a mass on the end of the spring. Look through all the data for natural frequency.
During treatment, log will become crooked. It causes by internal force. Therefore 2 support point is insufficient. It require support point in centre log lenght.
OK, I see. You are holding the log. I was thinking that the axes move the band saws. Normally this is a left and right band saw. Mills that cut bigger logs have two left and two right vertical band saws.
I am from Russia. There are many books about control system, but all books describe only theory. I have very inportent question: how to pass from theory to practice?
With practice! Getting training will be a big help. I can't imagine putting a system together without any help. We I am there is sort of an apprenticeship that engineers go through before being turned loose on their own. I provide training for many of the saw mill OEMs and but am in the Pacific NorthWest in the US. Northwest US and Canada have lots of sawmills and system integrators to keep them going. If you need a system integrator then let me know but you have to be serious about it.
In the US and Canada the standard saw mill PLC is the Rockwell Control Logix 5000. There are two main motion controllers used. The Rockwell M02AS and the Delta Computer Systems, RMC100. Most use the RMC100. There is a new RMC150 but most of the system integrators are just starting to use the newer controller.
These modern controller have auto tuning and will interface directly to Balluff or Temposonic MDT rods. Temposonic MDT rods are standard too with Balluff a distant second. Both the M02AS and the RMCs output +/- 10 volts to drive the valve. After you get the system scaled and the limits set you tune or auto tune the system. Then you try issuing a command with the position velocity and acceleration. The following link is the startup guide for the RMC150.
The motion commands are relatively simple. A move command consist of a position, velocity, acceleration, deceleration. The motion controller uses this information to generate a motion profile. If you issue the same motion profile to two or more axes at the same time then all of the axes will move together. Each axis will follow its own target but all the targets will be the same. The target position get updated every millisecond or faster. The PID compares the actual position from the MDT feedback with the target position. If the PID and feed forwards are tuned correctly then the actual position will always be very close to the target positions. There are status bits that can be monitored that tells you when the axis is in position or when an error occurs.
