METHOD FOR CONTROLLING OR REGULATING A CLOSING MECHANISM OF A MOULDING MACHINE

Abstract

In a method for controlling or regulating a closing mechanism of a moulding machine, a first trajectory for the controlled or regulated movement of the movable platen is calculated using a first algorithm based on operator inputs relating to the desired movement of the movable platen, and the movable platen is moved in a controlled or regulated manner at least once according to the first trajectory. At least one dynamic or kinematic variable of the closing mechanism is measured during at least one of the movements of the movable platen according to the first trajectory, and an estimate of at least one parameter value is generated based on the measurement. A second trajectory for the controlled or regulated movement of the movable platen is calculated based on the estimate, and the movable platen is moved in a controlled or regulated manner according to the second trajectory.

Claims

1. A method for controlling or regulating a closing mechanism of a moulding machine, in which a movable platen is moved by a movement mechanism, wherein: a first trajectory for the controlled or regulated movement of the movable platen is calculated, using a first algorithm, on the basis of operator inputs relating to the desired movement of the movable platenand in particular on the basis of at least one predefined parameter value for at least one dynamic or kinematic variable of the closing mechanism, the movable platen is moved in a controlled or regulated manner at least once according to the first trajectory, at least one dynamic or kinematic variable of the closing mechanism is measured during at least one of the movements of the movable platen according to the first trajectory, an estimate of at least one parameter value is generated on the basis of the measurement, a second trajectory for the controlled or regulated movement of the movable platen is calculated on the basis of the estimate, using an optimization algorithm, and the movable platen is moved in a controlled or regulated manner according to the second trajectory.

2. The method according to claim 1, wherein the optimization algorithm is used as the first algorithm.

3. A moulding machine comprising: a closing mechanism, with a movable platen and a movement mechanism for the movable platen, a control or regulation device for controlling or regulating the movement of the movable platen by the movement mechanism, an operator interface for entering operator inputs into the control or regulation device, a first algorithm for calculating a first trajectory for the controlled or regulated movement of the movable platen on the basis of operatory inputs entered by means of the operator interface relating to the desired movement of the movable platen, in particular on the basis of at least one predefined parameter value for at least one dynamic or kinematic variable of the closing mechanism, and a measurement device for measuring the at least one dynamic or kinematic variable of the closing mechanism during at least one movement of the movable platen according to the first trajectory, wherein the control or regulation device is formed to generate an estimate of at least one parameter value, wherein the control or regulation device is formed to calculate a second trajectory for the controlled or regulated movement of the movable platen on the basis of the estimate, using an optimization algorithm, and wherein the control or regulation device is formed to control or regulate the movement of the movable platen by means of the movement mechanism according to the second trajectory.

4. The moulding machine according to claim 3, wherein the moulding machine is formed as an injection-moulding machine.

5. The moulding machine according to claim 1, wherein the first algorithm is the optimization algorithm.

6. The moulding machine according to claim 3, wherein the first algorithm is the optimization algorithm.

Description

[0040] Embodiment examples of the invention may be discussed with reference to FIGS. 1 to 3:

[0041] FIG. 1 shows a schematic representation of an embodiment example of the method according to the invention. In this embodiment example, the optimization algorithm 5 is also used as first algorithm 4, in order to calculate a first trajectory. With reference to the measurement results, using estimated dynamic and kinematic parameters, again using the optimization algorithm 5, a second trajectory can be used. Although this procedure can be repeated as often as desired, one pass through the loop should normally be sufficient.

[0042] FIG. 2 shows a schematic representation of a further embodiment example of the method according to the invention, in which the above-discussed use of the optimization algorithm 5 as first algorithm 4 (loop) is only optional. The first trajectory can be entered or calculated as desired by means of a first algorithm 4 different from the optimization algorithm 5.

[0043] FIG. 3 shows a schematic representation of a moulding machine according to the invention.

[0044] A moulding machine 1 in the form of an electric toggle clamp machine is provided, which carries out both the closing movement and the build-up of closing force with a toggle lever (through the suitable translation of the toggle lever). The closing movement and the build-up of closing force should be carried out optimally with respect to different criteria taking into consideration certain boundary conditions.

[0045] Possible boundary conditions are: [0046] The desired moulding stroke (injection stroke), this is predefined by the operator and is determined by the mould and its properties. [0047] Machine limitations, such as maximum motor torques, currents in the motors and converters, maximum movement speeds and changes in speed or changes in acceleration in mechanical components such as spindles or bearings. [0048] Mould protection, i.e. maximum speed of the mould at the time of closing and maximum speed progression immediately before the mould is closed, in order to protect the mould from destruction and to facilitate necessary braking.

[0049] A possible optimization criterion is [0050] the cycle time, which includes, as an essential element, both the closing time and the time needed for the build-up of closing force.

[0051] The boundary conditions, as well as the optimization criterion or the optimization criteria, have to be formed into basic mathematical equations before an optimization in a known manner. Although the hard boundary conditions, such as for instance the moulding stroke or the maximum regulator voltage, are easily describable, they have to be parameterized specifically for each moulding machine 1. With the aid of a linking between machine data and component data, the boundary conditions can be determined. In most cases this occurs via a technical database of the components built into a moulding machine 1 in which the parameters of the machine components are stored.

[0052] In addition, the dynamic model which is to be complied with in an equivalent manner as a boundary condition (both in reality and in the case of correct parameterization within the mathematical model) is much more complex and is usually represented in the form:

m(x,p){umlaut over (x)}+g(x,{dot over (x)},p)=f(x,u,p),

wherein x is the movement, m represents the inertia terms, u represents the input (e.g. current or torque) and p represents known and unknown parameters.

[0053] In addition to the boundary conditions, the optimization criteria have to be represented by a mathematical formulation. The simplest and trivial representation is the quality functional J, which represents the movement time:

[00001]$J={?}_0^{\mathrm{x\_end}}.Math.\frac{1}{\stackrel{.}{x}}.Math.\mathrm{dx}.$

[0054] Due to the combination of time and movement limits, such as for instance the ratio between time and jolt, the representation of the quality functional can become much more complex. On the other hand, an energy function can also be included in the quality functional.

[0055] With the aid of suitable algorithms, such as for instance with the aid of the optimization algorithm described in AT 502 382 B1, a first trajectory can thus be calculated for the chosen boundary conditions with the linking of machine data and component data.

[0056] The movable platen is moved by the movement mechanism in a controlled or regulated manner according to the first trajectory and the at least one dynamic or kinematic variable of the closing mechanism for which only a predefined parameter value was present in the calculation is measured.

[0057] On the basis of the measurement, an estimate of the at least one parameter value predefined for the calculation of the first trajectory is generated.

[0058] On the basis of the estimate, using the optimization algorithm, a second trajectory for the controlled or regulated movement of the movable platen is calculated and the movable platen is moved in a controlled or regulated manner according to the second trajectory.

[0059] FIG. 3 schematically shows a moulding machine 1 with a closing mechanism, not represented in more detail because it corresponds to the state of the art, with a movable platen and a movement mechanism for the movable platen and: [0060] a control or regulation device 2 for controlling or regulating the movement of the movable platen by the movement mechanism [0061] an operator interface 3 for entering operator inputs into the control or regulation device 2 [0062] a first algorithm 4 for calculating a first trajectory for the controlled or regulated movement of the movable platen on the basis of operator inputs entered by means of the operator interface 3 relating to the desired movements of the movable platen and in particular on the basis of at least one predefined parameter value for at least one dynamic or kinematic variable of the closing mechanism [0063] a measurement device 6 for measuring the at least one dynamic or kinematic variable of the closing mechanism during at least one movement of the movable platen according to the first trajectory

[0064] The control or regulation device 2 is formed: [0065] to generate an estimate of the at least one parameter value on the basis of the measurement and [0066] to calculate a second trajectory for the controlled or regulated movement of the movable platen on the basis of the estimate, using an optimization algorithm 5, and [0067] to control or regulate the movement of the movable platen by means of the movement mechanism according to the second trajectory.

[0068] The first algorithm 4 and/or the optimization algorithm 5 can be stored e.g. in the control or regulation device. It can also be stored outside the moulding machine 1 in a manner accessible to the control or regulation device 2 (e.g. in a cloud).