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Post by clyevo on Oct 14, 2015 14:44:46 GMT
Thanks clyevo ..... that is very good info you have there and i appreciate the help. Since the oscillation problem started before i changed the pd160 value from 0 to 1, and it persisted after i changed the value, my conclusion is that this variable is not the culprit. so at the moment i am still having the oscillation problem. I have played around with the PID values in the AMC board and there is no noticeable difference in the rate of oscillation. You mean if u reduce the P value, there is no change whatsoever in the oscillation amplitude? That is weird. Can you show the sensor reading particularly the range it oscillate eg: 49-51? This is to rule out problem with sensor and to determine if it really is oscillating at parking position and not outside the sensor 0-100 range, just in case. BTW u bought the ULN2803 chip, u didnt use relay? I didnt notice the relay sound there.
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Post by clyevo on Oct 14, 2015 14:54:14 GMT
I just notice the relay in your video. If u using relay switch, there is no need to jump DCM to ACM. You need to connect DCM to the relay switch directly. Can you show the picture of your relay switches wiring or better yet provide the diagram of your wiring connections - amc 1280 to relay and relay to inverter?
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Post by jthiani on Oct 14, 2015 20:59:14 GMT
To answer your first question about amplitude, that is correct. no noticeable difference with a change to the pid values. Second i think the sensor is working just fine because when i change the direction in the AMC board, the oscillation position shifts by 180 degrees. Third, i do not have the relay board connected at this time. i have the ULN2803 chips.
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Post by jthiani on Oct 15, 2015 1:40:58 GMT
Ok i just connected the relay board to the direction outputs and i get the same thing. Continuous oscillation. I thought the problem might be caused by the way i had the sensors wired so i got a spare sensor with a new shielded wire and connected it directly to the amc and it is still oscillating. Every variable i have tried has not fixed or changed the problem.
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Post by clyevo on Oct 15, 2015 2:12:40 GMT
If the oscillation change direction by 180 degree then it oscillate at 0% sensor reading and 100% sensor reading? definitely not at parking position which is 50% sensor reading
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Post by clyevo on Oct 15, 2015 2:19:10 GMT
tronicgr might chime on this, if PID doesnt change the amplitude and frequency of the oscillation, then it is not the AMC1280 problem. So might be sensor position or inverter settings. Most likely the latter since you already change the sensor. I am not sure if your sensor is 360 degree or 180 degree so my previous post can be a bit different if u use 360 degree sensor. Btw what kind of sensor are u using?
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Post by tronicgr on Oct 15, 2015 4:03:44 GMT
Been busy all afternoon, and now its time for bed, but I can give you a hint.
Did you reduce the max motor speed? Also did you reduce the min motor speed to 0? Both on the amc1280usb LCD menu.
I still think the VFD delays to change the direction thus the overshoot. Either ramp values or internal PID is messing with it.
Thanks Thanos
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Post by jthiani on Oct 15, 2015 4:33:50 GMT
yes .... i tried those values and they didnt work. i have worked on this today with a friend for 10 hours and i am mentally drained. i think the problem may be with the AMC board because there is a small button next to the potentiometer that when pressed made everything freeze. I really need to talk to you @thanos. please call me tomorrow.
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Post by Mitch on Oct 15, 2015 7:46:57 GMT
Thanks for the fast response ..... so the values for pd160 are 0 - (set by operator) and 1 - (set by external terminals 0-10v) .... factory default is 0 so i changed it to 1. I did not however change any of the other pid values in the vfd. So if i understand your reply, pd161 should be 100% (which it is as this is the factory default) and i should lower the value of pd157 which has a default of 5.0. also should i change pd156 which has a default of 100% ?? .. thanks Mitch the PID function on the inverter is used for example if the motor is a fan and regulating temperature of an object the fan is cooling You have two analog input, VI and AI Let say VI is used to accept feedback 0-10v (in this case 0v being cool and 10v being the hottest) which translate to the frequency/speed of 0-50hz or 0rpm-1400rpm If u set the pd160 to 1, the second analog signal (AI) will be used to determine the PID strength 0-100%(pd161 and pd162) which determined how sensitive it is to the temperature changes This PID strength can then be change remotely - for example by an operator sitting in a control center in the factory This means the VI is not directly controlling the speed of the motor, it goes through a process control (PID) producing the calculated appropriate speed/frequency sent to the motor. so in your situation right now since the AMC1280 has the process control (PID) and the one accepting the feedback sensor -> there is no reason to use the inverter process control (PID) so the PID control (pd160) should be 0 - set by operator means it will use the PD159(default 0%) value that you set within the inverter settings its meant to be 0% because you are not using this function so the only analog signal accepted by your inverter will be use to control the frequency/speed (0-50/60hz) and is provided by AMC1280 and nothing else BTW, there is usually a different PID settings on the inverter has something to do with inertia of your system (the mass/weight of your platform and all) and still needed for sensorless vector control because it uses this to achieve greater accuracy, you can tune the the inertia settings once you put all the weight including your friend on the platform seat. Usually the default settings is for a continuous rated load. In your case the weight the motor take might be lighter and will vary depending on platform position so you still need to tune it manually. Whether u have it or not depends on your inverter model which i am not sure in your case. At least that is what i understand from my inverter manual book. Clyevo - curious, do you have the same inverter? To summarize my understanding of what you're saying in the quoted post - you're saying Pd160 when set to 1 allows for the P gain to be set by an analog inputs. This doesn't really make sense based on what I read in his inverter manual - Pd160 set to 1 allows pd159 (the target value) to be changed by an analog input of 0-10v, the target value is in % of frequency, it doesn't change the gain of P, I or D - just the target value. So, I would not set P to zero unless it's explicitly stated that this disables the VFD PID control, by doing so you'll be multiplying P by 0, so instead set it to 100%, and I to Zero, D to Zero. Also, Clyevo is right saying the AMC should be doing all PID, the goal is to disable the VFD PID altogether and let the AMC have control. I'll post some other settings in a new post.
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Post by Mitch on Oct 15, 2015 8:05:21 GMT
yes .... i tried those values and they didnt work. i have worked on this today with a friend for 10 hours and i am mentally drained. i think the problem may be with the AMC board because there is a small button next to the potentiometer that when pressed made everything freeze. I really need to talk to you @thanos. please call me tomorrow. I don't have this inverter, I just had a quick look at the manual, here are some thoughts for consideration before I head to bed. There are a couple of circuits at work - you should have one 0-10V circuit for signal, and another circuit that supplies the run commands, don't mix them. Keep in mind source vs sink - are you (sourcing) supplying current to the VFD, or (sinking) supplying a ground for current you are receiving from the VFD? Connections on your VFD: Multi input 1 (fwd) Multi input 2 (rev) +10 is +10V power supply for speed setting VI ( reference for 0-10v for freq) ACM (common for analog and control signals) VFD Settings:Pd001 = 1 (run command - this is the inputs to multi input 1 or 2) Pd002 = 1 (frequency command - this will be the 0-10v signal) I am going to assume you have input frequency and voltage set properly, and the motor max frequency set properly, accel/decel times etc. Pd003 to Pd0024 and Pd141 to Pd144 (name plate voltages and currents) Function of input terminal:Pd044 D1 = 02 (Fwd) Pd045 D2 = 03 (Rev) Pd070 = 0 (0-10V analog signal) PID: Pd156=100% (P) Pd157=0 (I) Pd158=0 (D) Pd159=(Target=% of freq as controlled by analog voltage signal, activated by Pd160) Pd160=1
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Post by clyevo on Oct 15, 2015 9:06:49 GMT
the PID function on the inverter is used for example if the motor is a fan and regulating temperature of an object the fan is cooling You have two analog input, VI and AI Let say VI is used to accept feedback 0-10v (in this case 0v being cool and 10v being the hottest) which translate to the frequency/speed of 0-50hz or 0rpm-1400rpm If u set the pd160 to 1, the second analog signal (AI) will be used to determine the PID strength 0-100%(pd161 and pd162) which determined how sensitive it is to the temperature changes This PID strength can then be change remotely - for example by an operator sitting in a control center in the factory This means the VI is not directly controlling the speed of the motor, it goes through a process control (PID) producing the calculated appropriate speed/frequency sent to the motor. so in your situation right now since the AMC1280 has the process control (PID) and the one accepting the feedback sensor -> there is no reason to use the inverter process control (PID) so the PID control (pd160) should be 0 - set by operator means it will use the PD159(default 0%) value that you set within the inverter settings its meant to be 0% because you are not using this function so the only analog signal accepted by your inverter will be use to control the frequency/speed (0-50/60hz) and is provided by AMC1280 and nothing else BTW, there is usually a different PID settings on the inverter has something to do with inertia of your system (the mass/weight of your platform and all) and still needed for sensorless vector control because it uses this to achieve greater accuracy, you can tune the the inertia settings once you put all the weight including your friend on the platform seat. Usually the default settings is for a continuous rated load. In your case the weight the motor take might be lighter and will vary depending on platform position so you still need to tune it manually. Whether u have it or not depends on your inverter model which i am not sure in your case. At least that is what i understand from my inverter manual book. Clyevo - curious, do you have the same inverter? To summarize my understanding of what you're saying in the quoted post - Pd160 when set to 1 allows for the P gain to be set by an analog inputs. This doesn't really make sense based on what I read in his inverter manual - Pd160 set to 1 allows pd159 (the target value) to be changed by an analog input of 0-10v, the target value is in % of freqency, it doesn't change the gain of P, I or D. So, I would not set P to zero unless it's explicitly stated that this disables the VFD PID control, you'll be multiplying P by 0 so set it to 100%, and I to Zero, D to Zero. Clyevo is right about using the AMC PID, the goal is to disable the VFD PID altogether and let the AMC have control. I'll post some other settings in a new post. First impression of V/F control to me is that it does not have inertia settings which is Kp Ki settings. This is what i see from my inverter. I am not very sure about this. But i will google more about V/F control and PID/Kp Ki/inertia settings. yes that is correct, so that uses VI i think I reviewed the HY manual and my manual, i got the term mix up, target value is not PID strength or sensitivity of the PID process control, it is simply the percentage of the frequency that is being produced by the first analog. So your statement is correct if in my example the temperature is always at 10v. In the diagram below temperature is feedback value, and target value is PID preset percentage. So the pd160 should be set to 0 which is default value of the inverter i because we not using this function. This is equivalent to target value or the second analog signal that i mention in the example of the temperature control thing in my previous post. This is the equivalent of the feedback sensor or the temperature measured in 0-10v, with 10v being the hottest in the example. This is the first analog signal that the inverter accept in the example posted in the previous post. It is good to know this things though, i am always eager to learn the functions even though it might not be used in our application. Sorry to take much space on the thread though, I hope jthiani problem can be resolved.
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Post by tronicgr on Oct 15, 2015 13:29:10 GMT
Joseph,
Can you write down here all the values of the parameters in Amc1280usb LCD menu? Must be something else messing up (sensor limits perhaps?)
Thanks Thanos
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Post by jthiani on Oct 15, 2015 22:49:10 GMT
I have left town for the weekend ... i will resume this on Wednesday and i will post my findings.
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Post by jthiani on Oct 30, 2015 3:25:28 GMT
I have been away for a few weeks but i will be getting back on this next week. Thanos was kind enough to send me another board to test and see if i can get it to work and i initially got the same oscillation but when i turned the AREF knob to the opposite end, the oscillation stopped and the motor just kept turning no stop. I have not done any more figuring out since then. I however have realized that i am not even sure what is supposed to happen when everything is working correctly in offline mode. So can someone please tell me what i should expect when everything is connected and working correctly?? My understanding is that i should have no movement from the motors once they find home position and the buttons on the AMC1280USB board should be able to make the motors move ... is this correct ??
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Post by clyevo on Oct 30, 2015 7:35:35 GMT
I have been away for a few weeks but i will be getting back on this next week. Thanos was kind enough to send me another board to test and see if i can get it to work and i initially got the same oscillation but when i turned the AREF knob to the opposite end, the oscillation stopped and the motor just kept turning no stop. I have not done any more figuring out since then. I however have realized that i am not even sure what is supposed to happen when everything is working correctly in offline mode. So can someone please tell me what i should expect when everything is connected and working correctly?? My understanding is that i should have no movement from the motors once they find home position and the buttons on the AMC1280USB board should be able to make the motors move ... is this correct ?? That is correct. The AMC1280 settings all at default? Do you FabisThanosBoardConfigurator? Can you give screenshot of the controller config tab? Take pictures of the potentiometer terminal and show picture of the amc1280usb and show picture of the inverter terminal while everything is connected. Who knows it could be wrong wiring.
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