CS-Lab CSMIO/IP-A, Tuning Manual

Page 1: ... copyright CS Lab s c 2020 Rev 1 1 08 2021 CSMIO IP A 6 axis CNC motion controller 10V Manual Tuning Guide with Mach4 software APPLIES TO HARDWARE VER v2 FP4 v2 H7 FIRMWARE software v3 xxx Mach4 ...

Page 2: ...rvo drive a bad condition of servo magnets fault in the control signal 10V connection originally low sensitivity and sluggishness of a servo drive substantial interference caused by incorrect connection of a servo drive too strong filters of the set or actual speed of a servo drive The test which consists in connecting a manual voltage generator 9V battery potentiometer or a labora tory power supp...

Page 3: ...back signal You can use an optical scale an encoder an incremental signal emulator output of a servo drive In all cases we mean an incremental signal compliant with the RS422 standard i Check the feedback operation encoders and scales operation test For the feedback test you need to move an axis in both directions when Mach4 is at Disable status and watch axis DRO on the Mach4 screen simultaneousl...

Page 4: ...ands issued e g from the JOG You should not use higher values of the kP parameter than necessary be cause it may have a negative impact on the final tuning effect 4 Switch Mach4 to Enable and try to make a slow move in Jog mode It is recommended to use a very low Jog Rate value usually 1 is enough Such a low value is used since our goal at present is only to check that the axis will respond correc...

Page 5: ...o drive or its connection When the effect is positive i e the axis will perform slow motion orders given from the Jog level and after covering a longer distance the PID Fault error will not appear you can proceed to the next stage 5 Switch Mach4 to Enable and press the Auto buton to automatically set the Zero Offset value The automatic configuration consists in entering to the Zero Offset paramete...

Page 6: ... and Time t Div time base parameters have been selected to emphasize the waveforms of both channels as much as possible It may be necessary to use other values of the parameters Val Div and Time t Div because they de pend on the values of velocity acceleration and distance with which the axis will move during manual tuning as well as the quality of tuning and sensitivity of servo drives 8 Prepare ...

Page 7: ... value and a number of oscillo scope grids covered by the top or bot tom part of the waveform In this situa tion the upper part took up a bit over two grids and the Val Div value is 0 2mm It s is easy to calculate 2 x 0 2mm 0 4mm On the oscilloscope screen there is also the green waveform presenting Mkit Ref Velocity value set velocity that an axis should get when making a set move and is expresse...

Page 8: ...ue for demonstration purposes you will notice that the Mkit Ref Velocity value creates a repeatable trapezoidal wave form This waveform is the ideal refer ence for the Trigger function If you do not know why the Mkit Ref Velocity value has the trapezoidal shape let us remind you that Mach4 uses a trapezoidal motion velocity profile ...

Page 9: ... drive which results in an unnecessarily high value of Mkit Following Error KVff is a value of velocity feed forward gain In simple terms the higher value of the kVff parameter the higher voltage value proportional to Mkit Ref Velocity value set velocity that an axis should get when making a set move will go directly to the 10V analog output of a CSMIO IP A controller Feed forward of velocity grea...

Page 10: ...sions that will help you under stand how a discussed parameter affects a servo drive s operation The processes presented in the slides may differ from waveforms obtained by users on their CNC machines Many factors cause it but the most important are quality of servo PID regulator tuning power and sensi tivity of a servo drive axis weight gear ratio velocity and acceleration value Below you can see...

Page 11: ... decreases Step 11 We reduce the Val Div to the value of 0 01 to enlarge the waveform Step 12 15 We increase the kVff by 0 001 the value of Mkit Following Error decreases Step 16 Further increasing of the kVff value by 0 001 causes the Mkit Following Error value changes sign to the opposite It means that the axis reached the set position but overtook it false start effect Step 17 We reduce the kVf...

Page 12: ...ing Error value will be willing to decrease and no dull knocking or axis oscillations will be noticeable In other words you should stop increasing the kP value when the difference between several consecutive values of Mkit Following Error will give a sim ilar result The condition is to increase the kP value in equal steps A too high value of the kP causes a too strong reaction of the PID regulator...

Page 13: ...of kP term tuning Step 18 21 We increase the kP by 0 02 the value of Mkit Following Error decreases eagerly Step 22 24 Further increasing of the kP by 0 02 causes the Mkit Following Error value to reduce reluctantly Step 26 27 Further increasing of the kP by 0 02 causes the Mkit Following Error value does not decrease and axis resonance intensifies We reduce the kP to Step 21 value and we consider...

Page 14: ...an unnecessarily high value of Following Error The kAff parameter is a gain value of acceleration feed forward In simplification the higher kAff value the higher value of voltage proportional to the value of Mkit Ref Acceleration the set accelera tion which an axis should get when making a set move will go to 10V analog output of CSMIO IP A controller Feed forward of acceleration highly supports t...

Page 15: ...ep 34 Step 35 Description of kAff term tuning Step 28 30 We increase the kAff by 0 1 the value of Mkit Following Error reduces Step 31 32 We increase the kAff by 0 1 the value of Mkit Following Error doesn t reduce Step 33 35 We increase the kAff by 0 1 the value of Mkit Following Error changes the sign We reduce the kAff value to Step 30 value and we consider it the target value and go to the nex...

Page 16: ... the kI causes the integral term of position PID regulator reacts to Mkit Follow ing Error value much faster and harder than a servo drive can provide what causes the before men tioned axis oscillation A too low value of kI parameter causes the integral term of position PID regulator reacts too slow and weak on the Mkit Following Error value what translates into an unnecessarily high value of Mkit...

Page 17: ... to create this guide we used a DELTA ASD B2 servo drive which implements the integral term of velocity PID regulator As we wrote previously the kI parameter of position PID regulator is used in situations when the servo drive velocity PID regulator doesn t have an integral term or does not fulfill its task sufficiently due to the servo drive s outdated design Start Step 36 Step 37 Step 38 Step 39...

Page 18: ... The kD is the value of integral term gain of position PID regulator In simplification the higher value of the kD parameter and the faster change of Mkit Following Error the stronger suppression of position PID regulator proportional and integral term activity This has a stabilizing effect on the operation of position PID regulators which in turn allows to some extent to increase the kP and kI val...

Page 19: ...www cs lab eu CS Lab s c CSMIO IP A 6 axis CNC controller Manual tunning 19 ...

Page 20: ...shold is determined by multiplying 3 or 4 times the maximum recorded Mkit Following Error while the axis moves at the maximum assumed speed This method of determining the Error Alarm Threshold value is universal and works well in any situation 3 After a successful manual tuning process we should thoroughly test the CNC machine and especially the operation of servo drives in the broadest possible r...