Electropneumatic control system and position controller for such a system
An electropneumatic control system for a pneumatic drive and electropneumatic position controller for the system, wherein a volume flow booster having a bypass valve is downstream of the position controller to increase the air capacity, where the pneumatic drive is run in a new operating mode multiple times at maximum air capacity in a first direction to support an operator in adjusting the bypass valve, and where upon exceeding a specified position, the air capacity is set to zero, an overshoot value of the pneumatic drive is determined and output for the operator on a display such that by varying adjustment of the bypass valve, the operator can find and set an adjustment of the valve having low overshoot such that with an adjustment found in such a manner, the transition behavior of the control system can be significantly improved without additional effort.
1. An electropneumatic control system for a pneumatic actuator, comprising:
an electropneumatic position controller having a microprocessor, said electropneumatic position controller generating a first pneumatic control signal in accordance with a predefined or predefinable position setpoint value and a measured actual value of the position of the pneumatic actuator; and
at least one volume booster for increasing an air flow rate of the electropneumatic position controller and for generating, as a function of the first pneumatic control signal, a second pneumatic control signal which is supplied to the pneumatic actuator, an adjustable bypass valve being disposed in a connection between the first and second pneumatic control signals;
wherein the electropneumatic position controller is configured to repeatedly move the pneumatic actuator automatically during an initialization mode of the electropneumatic position controller by applying air to or by exhausting air from at least one output until the measured actual value of the position of the pneumatic actuator fed back to the electropneumatic control system exceeds a predefined or predefinable new position setpoint value, maximum air flow rate in a first direction in each different setting of the adjustable bypass valve being automatically applied until the predefined or predefinable new position setpoint value is reached, to set the air flow rate to zero each time the predefined or predefinable new position setpoint value is overshot, and configured to determine an overshoot value of the pneumatic actuator for each respective setting of the adjustable bypass valve and output said determined overshoot value on a display; and
wherein the respective setting of the adjustable bypass valve is automatically adjusted to reduce the overshoot when the overshoot is detected and output.
2. The electropneumatic control system as claimed in claim 1 , wherein the electropneumatic position controller is further configured to move the pneumatic actuator repeatedly with maximum air flow rate in a second direction counter to the first direction in each different setting of the bypass valve until the predefined or predefinable new position setpoint value is reached, to set the air flow rate to zero each time the predefined or predefinable new position setpoint value is reached, and to determine the overshoot value of the pneumatic actuator and output said determined overshoot value on the display.
3. The electropneumatic control system as claimed in claim 2 , wherein the electropneumatic position controller is configured to display overshoot values as percentages as a function of an operating range of the pneumatic actuator between predetermined end positions.
4. The electropneumatic control system as claimed in claim 3 , wherein a first position is predefined in a range of between 10% and 40% of the operating range and a second position is predefined in a range of between 60% and 90% of the operating range; and wherein the electropneumatic position controller is configured to move the pneumatic actuator alternately from the first to the second position and to move the pneumatic actuator alternately from the second to the first position.
5. The electropneumatic control system as claimed in claim 4 , wherein the first position is predefined at 30% and the second position at 70% of the operating range.
6. An electropneumatic position controller for an electropneumatic control system, comprising:
a microprocessor; and
memory;
wherein the microprocessor is configured to generate a first pneumatic control signal as a function of a predefined or predefinable position setpoint value and a measured actual value of a position of a pneumatic actuator;
wherein at least one volume booster is disposable downstream of the electropneumatic position controller to increase an air flow rate thereof; and
wherein in order to adjust a bypass valve of the at least one volume booster, the electropneumatic position controller is configured to repeatedly move the pneumatic actuator automatically during an initialization mode of the electropneumatic position controller by applying air to or by exhausting air from at least one output until the measured actual value of the position of the pneumatic actuator fed back to the electropneumatic control system exceeds a predefined or predefinable new position setpoint value, maximum air flow rate in a first direction in each different setting of the adjustable bypass valve being automatically applied until the predefined or predefinable new position setpoint value is reached, to set the air flow rate to zero each time the predefined or predefinable position new setpoint value is overshot, and configured to determine an overshoot value of the pneumatic actuator for each respective setting of the adjustable bypass valve and output said overshoot value on a display; and
wherein the respective setting of the adjustable bypass valve is automatically adjusted to reduce the overshoot when the overshoot is detected and output.
7. A method for operating an electropneumatic control system for a pneumatic actuator comprising an electropneumatic position controller having a microprocessor, said electropneumatic position controller generating a first pneumatic control signal as a function of a predefined or predefinable position setpoint value and a measured actual value of the position of the pneumatic actuator and comprising at least one volume booster for increasing an air flow rate of the electropneumatic position controller and for generating, as a function of the first pneumatic control signal, a second pneumatic control signal which is applied to the pneumatic actuator, an adjustable bypass valve being disposed in a connection between the first and the second pneumatic control signals, the method comprising:
moving the pneumatic actuator repeatedly via the electropneumatic position controller automatically during an initialization mode of the electropneumatic position controller by applying air to or by exhausting air from at least one output until the measured actual value of the position of the pneumatic actuator fed back to the electropneumatic control system exceeds a predefined or predefinable new position setpoint value, maximum air flow rate in a first direction in each different setting of the adjustable bypass valve being automatically applied until the predefined or predefinable new position setpoint value is reached;
setting the air flow rate to zero each time the predefined or predefinable new position setpoint value is overshot;
determining an overshoot value of the pneumatic actuator for each respective setting of the adjustable bypass value and outputting said determined overshoot value on a display; and
adjusting the respective setting of the adjustable bypass valve automatically to reduce the overshoot each time an overshoot is detected and output.
8. A non-transitory computer program product encoded with a computer program executed by a microcontroller having a microprocessor, which causes operation of an electropneumatic control system for a pneumatic actuator having at least one volume booster with an adjustable bypass valve between a control input and an output of the volume booster, the computer program comprising:
program code for moving the pneumatic actuator repeatedly via the electropneumatic position controller automatically during an initialization mode of the electropneumatic position controller by applying air to or by exhausting air from at least one output until the measured actual value of the position of the pneumatic actuator fed back to the electropneumatic control system exceeds a predefined or predefinable new position setpoint value, maximum air flow rate in a first direction in each different setting of the adjustable bypass valve being automatically applied until the predefined or predefinable new position setpoint value is reached;
program code for setting the air flow rate to zero each time the predefined or predefinable new position setpoint value is overshot;
program code for determining an overshoot value of the pneumatic actuator for each respective setting of the adjustable bypass value and outputting said determined overshoot value on a display; and
program code for adjusting the respective setting of the adjustable bypass valve automatically to reduce the overshoot each time an overshoot is detected and output.
9. The non-transitory computer program product as claimed in claim 8 , wherein the non-transitory computer program product comprises a data carrier or storage medium.