Device and method for detecting dehydration imbalance of drum washing machine

Abstract

The invention provides a device and a method for detecting dehydration imbalance of a drum washing machine and solves the problems that an eccentric magnitude error is high, and the accuracy is poor because the imbalance is detected indirectly via an eccentric magnitude calculated according to a speed difference in the conventional detection technology. A control unit, a filtering unit and a calculating unit are arranged in a micro-computer controller. The method comprises the following steps of: (1) outputting a control signal by using a proportional-integral-derivative (PID) control system, and extracting and shaping the control signal by using a mid-value smooth filtering system, calculating the maximum deviation amplitude value and comparing the maximum deviation amplitude value with a set value to judge whether a requirement is met; (2) if the requirement is met, entering a low-speed dehydration step, otherwise, performing eccentricity correction; (3) after the low-speed dehydration step, judging whether the actual eccentric magnitude accords with a preset value for improving the dehydration rotation speed; and (4) if the actual eccentric magnitude accords with the preset value for improving the dehydration rotation speed, gradually improving the dehydration rotation speed according to levels until the preset highest rotation speed is reached. By the device and the method, effectiveness and accuracy of measuring and calculating the eccentric magnitude are obviously improved.

Description

technical field [0001] The invention belongs to the technical field of washing machines, and relates to a drum washing machine, in particular to a device and method for detecting unbalanced dehydration of a drum washing machine. Background technique [0002] With the development of white goods, drum washing machine is favored by many manufacturers as a new type of washing machine. It has the advantages of high cleaning ratio, water saving and power saving, and is also recognized and loved by more consumers. [0003] The ability to detect unbalanced dehydration of drum washing machines is a very important technical performance for determining washing machines, and it is an important indicator to measure the product quality of each drum washing machine manufacturer. [0004] The existing dehydration unbalance detection method generally adopts the method of speed difference to calculate the eccentricity of the washing machine inner drum to judge and detect the unbalance. This m...

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Problems solved by technology

[0004] The existing dehydration unbalance detection method generally adopts the method of speed difference to calculate the eccentricity of the washing machine inner drum to judge and detect the unbalance. This method does not detect the directly affecting parameters that cause eccentricity, but the indirect parameters of the speed change. Since the washing machine uses PID control technology to control the rotation speed of the inner drum to ensure a constant rotation speed, it partially offsets the influence of the eccentricity on the speed parameters, reducing the accuracy of this detection method

This unbalance detection technology adopts the method of determining the maximum rotation speed during dehydration according to the detected eccentricity at low speed, and it is impossible to prepare for detecting eccentricity during high-speed dehydration, so it cannot be adjusted according to the reduction of water in the clothes and the change of eccentricity Rotating speed

[0005] Another unbalance detection technique is to add a balance detection sensor, this method will increase the cost of the washing machine and the complexity of the control system

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