GB2157022A

GB2157022A - Monitoring plural drive control systems

Info

Publication number: GB2157022A
Application number: GB08505242A
Authority: GB
Inventors: Gerhard Laux; Viktor Satzger
Original assignee: Kombinat Textima VEB
Current assignee: Kombinat Textima VEB
Priority date: 1984-03-06
Filing date: 1985-02-28
Publication date: 1985-10-16
Also published as: DE3503178A1; ES8701391A1; FR2561008B1; DE3503178C2; GB2157022B; FR2561008A1; DD223267A1; CH674688A5; GB8505242D0; ES540948A0; JPS60205601A

Abstract

A control system for the coordinated regulation of n drives comprises a main controller which processes all the input values determining the total level of movement of the plant and n slave controllers which determine the movement relationship of the n drives as a function of time or condition and supply nominal values which are specific to the drives. For the purposes of dynamic monitoring, the difference between the largest and the smallest deviation of then drives is constantly calculated and compared with a maximum admissible difference and if this is exceeded the speed level of all the drives is lowered by the main controller to a predetermined limit in accordance with any functional relationship. If the fault persists further speed reductions are made until the apparatus comes to rest. The controlled apparatus may be a textile machine.

Description

SPECIFICATION A method for the regulation of n drives connected in parallel Field of application of the invention The invention relates to a method for the regulation of n drives connected in parallel for machining and processing machines with decentralized drives.

Characteristics of known technical solutions The suspension regulation method has been known up to now (German Patent Specification 2 924 070). Although this method enables the drives to be acted upon reciprocally, it has the drawback that it involves very high costs for more than two drives.

Aim of the invention The aim of the invention is to develop a method by means of which it is possible to maintain the necessary conditions and therefore ensure the quality parameters and reduce the consequences of operating errors or damage.

Description of the invention The object of the invention is to provide a method for the dynamic monitoring of positive movement and for protection against damage and incorrect operation. This object is solved in accordance with the invention in that downstream of a main nominal value generator which processes all the input values which determine the overall movement level of the plant, there are connected n partial nominal value generators which determine the movement relationship of the n drives as a function of time or condition and supply nominal values specific to the drives, in which for the purposes of dynamic monitoring, the difference between the largest and the smallest deviation of the n drives is constantly determined and is compared with a maximum admissible difference and if the difference is exceeded the speed level of all the drives is lowered to the predetermined limit in accordance with any operational relationship by the main nominal value generator whilst ensuring the reciprocal relationship of movement. So that the correction signal does not alternate constantly, a zone of non-sensitivity is established around the technically determined uppermost limit, in which zone there is no reaction to changing deviation differences.

Embodiment The microcomputer controlled digital regulation of a flyer with a decentralised drive, in which the drives of bobbins, drawing frames, spooling carriages and beaters are to be accurately coordinated, is taken as an example. The function of the main nominal value generator is to link the input values, the speed level and the guide transfer function formed as a sinoide during each scanning cycle in a multiplicative manner. The output value is a normalized conductance which is linked in a multiplicative manner in the four partial nominal value generators in each case with the values which include the corresponding ratio of movement for each of the number of positions of the roving wound on the bobbin.The partial nominal value generators of the bobbin and the spooling carriage are also designed to process correction values which are derived from a slub tension resulting from inaccurate technological characteristics. The quality parameter of a uniform thread tension is achieved by accurate initial nominal value settings which are specified in a generation cycle. It is possible for deviations in the form of lag errors to arise during operation, which errors must not be unnoticed during transfer processes as regards their effect on the quality of positive movement. In this respect equal deviations do not play a decisive role as regards their amount and difference as they lead to an approximately equal percentage change and do not therefore damage the positive movement conditions. Drafting errors as regards the material are caused when the drive deviations are of a different size.This may be the case if there is incorrect operation in the sense that one or more control elements are unable to follow the initial settings, for example as a result of a load which is too great or which changes during the process. In this respect the invention uses the fact that lag errors are proportional to speed. A further possibility involves stochastic malfunctions or damage. If the difference between the largest and the smallest deviation is greater than an admissible limit, a correction value is integrally determined during each regulation cycle by the continuous summing of a constant K which may be freely determined, which correction value is subtracted from the actual conductance in each case. As long as the deviation difference remains lower than the limit, the correction value remains constant.When a reverse trend in the disturbing factor is detected, the correction value is correspondingly reduced. As there is a zone of non-sensitivity at the point of inversion, the correction sign 1 is prevented from continuously alternating. The correction is continued until the plant is at a standstill if the positive movement conditions have not been satisfied during the decrease. This is signalled as damage and requires testing and removal of the damage before the plant can be brought back into operation. The constant K should be selected such that the correction acts rapidly, but not so that additional factors are involved in the malfunction of the positive movement as a result of a modification of the conductance which is too great.

1. A method for the digital regulation of n drives connected in parallel, characterised in that downstream of a main nominal value generator which processes all the input values determining the total level of movement of the plant, there are connected n partial nominal value generators which determine the movement relationship of the n drives as a function of time and condition and supply the nominal values specific to the drives, in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A method for the regulation of n drives connected in parallel Field of application of the invention The invention relates to a method for the regulation of n drives connected in parallel for machining and processing machines with decentralized drives. Characteristics of known technical solutions The suspension regulation method has been known up to now (German Patent Specification 2 924 070). Although this method enables the drives to be acted upon reciprocally, it has the drawback that it involves very high costs for more than two drives. Aim of the invention The aim of the invention is to develop a method by means of which it is possible to maintain the necessary conditions and therefore ensure the quality parameters and reduce the consequences of operating errors or damage. Description of the invention The object of the invention is to provide a method for the dynamic monitoring of positive movement and for protection against damage and incorrect operation. This object is solved in accordance with the invention in that downstream of a main nominal value generator which processes all the input values which determine the overall movement level of the plant, there are connected n partial nominal value generators which determine the movement relationship of the n drives as a function of time or condition and supply nominal values specific to the drives, in which for the purposes of dynamic monitoring, the difference between the largest and the smallest deviation of the n drives is constantly determined and is compared with a maximum admissible difference and if the difference is exceeded the speed level of all the drives is lowered to the predetermined limit in accordance with any operational relationship by the main nominal value generator whilst ensuring the reciprocal relationship of movement. So that the correction signal does not alternate constantly, a zone of non-sensitivity is established around the technically determined uppermost limit, in which zone there is no reaction to changing deviation differences. Embodiment The microcomputer controlled digital regulation of a flyer with a decentralised drive, in which the drives of bobbins, drawing frames, spooling carriages and beaters are to be accurately coordinated, is taken as an example. The function of the main nominal value generator is to link the input values, the speed level and the guide transfer function formed as a sinoide during each scanning cycle in a multiplicative manner. The output value is a normalized conductance which is linked in a multiplicative manner in the four partial nominal value generators in each case with the values which include the corresponding ratio of movement for each of the number of positions of the roving wound on the bobbin.The partial nominal value generators of the bobbin and the spooling carriage are also designed to process correction values which are derived from a slub tension resulting from inaccurate technological characteristics. The quality parameter of a uniform thread tension is achieved by accurate initial nominal value settings which are specified in a generation cycle. It is possible for deviations in the form of lag errors to arise during operation, which errors must not be unnoticed during transfer processes as regards their effect on the quality of positive movement. In this respect equal deviations do not play a decisive role as regards their amount and difference as they lead to an approximately equal percentage change and do not therefore damage the positive movement conditions. Drafting errors as regards the material are caused when the drive deviations are of a different size.This may be the case if there is incorrect operation in the sense that one or more control elements are unable to follow the initial settings, for example as a result of a load which is too great or which changes during the process. In this respect the invention uses the fact that lag errors are proportional to speed. A further possibility involves stochastic malfunctions or damage. If the difference between the largest and the smallest deviation is greater than an admissible limit, a correction value is integrally determined during each regulation cycle by the continuous summing of a constant K which may be freely determined, which correction value is subtracted from the actual conductance in each case. As long as the deviation difference remains lower than the limit, the correction value remains constant.When a reverse trend in the disturbing factor is detected, the correction value is correspondingly reduced. As there is a zone of non-sensitivity at the point of inversion, the correction sign 1 is prevented from continuously alternating. The correction is continued until the plant is at a standstill if the positive movement conditions have not been satisfied during the decrease. This is signalled as damage and requires testing and removal of the damage before the plant can be brought back into operation. The constant K should be selected such that the correction acts rapidly, but not so that additional factors are involved in the malfunction of the positive movement as a result of a modification of the conductance which is too great. CLAIMS

1. A method for the digital regulation of n drives connected in parallel, characterised in that downstream of a main nominal value generator which processes all the input values determining the total level of movement of the plant, there are connected n partial nominal value generators which determine the movement relationship of the n drives as a function of time and condition and supply the nominal values specific to the drives, in which for the purposes of dynamic monitoring the difference between the smallest and the largest deviation of the n drives is constantly calculated and is compared with a maximum admissible difference and in that if the difference is exceeded the speed level of all the drives is lowered to a predetermined limit in accordance with any functional relationship by the main nominal value generator whilst ensuring the reciprocal movement relationship.

2. A method as claimed in claim 1, characterised in that a zone of non-sensitivity is established around the technologically ascertained uppermost limit, in which zone there is no reaction to changing deviation differences.

3. A method according to claim 1 or 2, utilised to control textile machinery.

4. A method according to claim 3 utilised to control a flyer.

5. A method according to any preceding claim and substantially as herein described.

6. Apparatus configured to perform a method as claimed in any preceding claim.