Mita Industrial Co., Ltd.

Yoshiki Shimomura

Tetsuo Tomiyama

Yasushi Umeda

Hiroyuki Yoshikawa

Sadao Tanigawa

Kazuhiro Ogawa

Yukihiro Mori

Kenji Katsuhara

Toshimitsu Takakura

Yasuo Motegi

Tomohiko Sakao

Hirofumi Nishino

Hiroshi Kusumoto

Yoshifumi Ishii

Kazuto Hori

Yuichi Koike

A sheet transportation device for use in an image forming apparatus is provided which has self-diagnosis and self-repair functions. The sheet transportation device has a sheet transportation system including a plurality of units (8). A control sequence for a sheet transportation operation is applied from a system body (10) to the respective units (8). The units (8) each execute the control sequence to perform the sheet transportation operation. The units (8) are each constructed so as to perform an autonomous operation. This construction allows the respective units to autonomously perform self-diagnosis and repair operations. The fault diagnosis and repair operations are performed in parallel to the sheet transportation control. Therefore, the sheet transportation device can flexibly adapt itself to an external influence such as a change in the use environment and a malfunction due to a time-related change such as the aging of components thereof. Thus, the sheet transportation device ensures a highly reliable operation and yet requires less labor for the maintenance and inspection.

Sheet transportation device

A simulation system is provided which is capable of simulating the behavior of a sheet transported by a transportation system. In response to application of a control sequence formulated for the sheet transportation system, a simulation is performed to check how the sheet is to be transported in the sheet transportation system on the basis of the applied control sequence. Necessary data are extracted from hardware systems constituting the real sheet transportation system. On the basis of the extracted data, a virtual sheet transportation system is constructed in a computer, and the sheet is represented by information indicative of the locations of opposite ends of the sheet and the distance therebetween. The sheet thus represented is moved by a predetermined unit distance in the virtual sheet transportation system on the basis of the control sequence, and data is computed for every movement of the sheet.

Simulation system for control sequence for sheet transportation

The present invention makes it possible to make good self-repair on which little secondary effect is exerted by calculating a manipulated variable of a parameter at the time of the repair by a functional amount in an image forming apparatus having a self-repair function. When a fault occurs, control-type repair for operating a physical parameter is first made. In this repair, the physical parameter to be operated is searched for (n3). If the physical parameter to be operated is determined, a manipulated variable of the physical parameter is then calculated by a functional amount (n4). The manipulated variable of the parameter by the functional amount is determined by adjusting the degree to which a plurality of functions are developed. Therefore, a manipulated variable in which the development of the functions is most preferable as the entire apparatus is determined. If the fault cannot be repaired by the control type repair, functional redundancy type repair is made (n6, n7, n8, n9). In the functional redundancy type repair, priorities to repair candidates are determined by the functional amount.

Self-reparir type image forming apparatus utilizing functional

According to the present invention, a concept of functional quantities indicative of quantified functional degrees of such lower-level functions as 'clearer characters', 'cleaner background', and 'thicker characters', which are subordinating to a qualification-oriented function of 'more beautiful characters'. Characteristic patterns of functional quantities F1, F2 and F3 of the lower-level functions for physical parameters (for example, the surface potential of a photoreceptor body) are prepared. When a fault repair is implemented by changing a value of a physical parameter, a tradeoff occurs between lower-level functions which are influenced by the physical parameter. That is, taking into account the functional quantities F1, F2 and F3 of the lower-level functions, the value of the physical parameter is set so that the functional quantity of the function of 'more beautiful characters' is maximized. By introducing the concept of the functional quantities indicative of the quantified functional degrees of the functions, a flexible self-repairing function can be realized, thereby optimizing a repair operation.

Apparatus having self-repairing function and method of self repairing

A method of automatically creating control sequence software required for a machine system controlled by a computer includes four algorithms, that is, 'derivation of control sequence specification'.fwdarw.'derivation of a qualitative control sequence'.fwdarw.'addition of quantitative information (derivation of a quantitative control sequence)'.fwdarw.'generation of a C program'. The qualitative control sequence is a state transition matrix following the time sequence. This qualitative control sequence is derived by making use of a qualitative inference system. A quantitative control sequence is obtained by adding quantitative time between states to the qualitative control sequence. Time information is calculated on the basis of design information of a machine portion stored in a design information database. As a result, it is possible to reduce the manual burden on the software development by using the present invention.

Method of automatically creating control sequence software and apparatus

The present invention makes it possible to effectively make self-repair of a fault by referencing repair analysis cases. The cases are hierarchically classified according to the fault symptom, the fault and the class, and a case suitable for a fault developed is selected to perform repair work. In applying a case, the case is corrected as required. If work succeeded by the corrected case, the corrected case is registered in the same class as a class to which the original case belongs, to make each class rich in case contents.

Self-repair system for an image forming apparatus

In an image forming machine, an objective model storage device stores parameter data that represent elements of the machine and relationships among such parameters, and parameter membership functions, and fault diagnosis knowledge. A degradation storage device stores a fuzzy qualitative value for a parameter changed by degradation of an element of the machine. Preferably, degradation indicative data are converted into fuzzy qualitative values, and the value of the parameter changed by degradation is represented by a fuzzy qualitative value. The machine includes sensors for sensing functional states thereof, and providing state data representative of such states. The state data sensed by the sensors are converted into fuzzy qualitative values. Then, a fault judgement device determines whether or not a fault exists by comparing the obtained fuzzy qualitative values with the parameter data stored in the objective model storage device. If the fault judgement device determines that a fault exists, a fault diagnosis device performs fault diagnosis by utilizing, as an initial value, the value of the parameter changed by degradation. A specification device specifies fault causes by comparing the result of the diagnosis with the state data which was converted into the fuzzy qualitative values. Then, a repair device operates actuators of the machine to overcome the specified fault.

Image forming apparatus provided with self-diagnosis system

The amount of degradation, converted into a fuzzy qualitative value, is found on the basis of state data sensed by sensors 1a, 1b and 1c and degradation data. The value of a parameter changed by the amount of degradation is represented by a fuzzy qualitative value. In addition, the state data is converted into a fuzzy qualitative value, and it is judged by the value whether or not a fault exists. As a result, if a fault exists, fault diagnosis is made utilizing, as an initial value the value, of the parameter changed by the amount of degradation, and the causes of the fault are specified by comparing the result of the diagnosis with the state data converted into the fuzzy qualitative value. The causes of the fault specified are repaired by operating corresponding actuators 6a, 6b and 6c. Since the causes of the fault are specified while handling the fuzzy qualitative value, the causes of the fault can be specified more precisely. Accordingly, it is possible to achieve an image forming apparatus in which autonomy is high and repair labor is reduced.

Image forming apparatus provided with self-diagnosis and self-repair

In an image forming apparatus according to the present invention, a software portion incorporated in the apparatus is provided with a virtual case storage portion 12, to previously create virtual cases by a virtual case compiler 16 outside of the apparatus and store the virtual cases. Fault diagnosis is made by comparing fuzzy qualitative values into which the values of sensors are converted on the basis of fuzzy membership functions with the virtual cases. If a fault is diagnosed as a result of the comparison, repair operations for repairing the fault are read out from a work script table 15. In this case, operation information for repair are stored to correspond to each of a plurality of domains into which a state space which the apparatus can take up is divided. Accordingly, it is possible to correctly read out corresponding repair operations from the work script table 15 depending on which of the domains is a domain to which the present state of the apparatus belongs. As a result, a self-repair system can be constructed as a practical built-in type system, thereby to make it possible to reduce the scale of the system related to the fault diagnosis as well as to reduce time required for the fault repair.

Image forming apparatus having self-repair function and self-repair

An image forming apparatus has a functional redundancy system by which an inherent function normally performed by a certain portion is performed as a potential function by another portion, when such certain portion no longer can be perform its inherent function. In a first operative sequence, portions in the image forming apparatus perform their respective inherent functions. However, where a function of a certain portion in the apparatus is lost, for example, where a fault occurs and a particular element has failed, operation of other portions in the apparatus are controlled according to a second sequence. In the second sequence, the inherent function of the portion which has failed is replaced by the potential function of another portion in the apparatus.

Image forming apparatus having functional redundancy system

According to the present invention, a self-diagnosis system for an image forming apparatus can make accurate fault diagnosis and is made smaller in size and higher in speed. For that purpose, a fault temporarily developed by the image forming apparatus is limited to a single fault assumption, all states which can exist on the image forming apparatus when the image forming apparatus develops the fault are previously simulated, and the results of the qualitative simulation are stored as a plurality of virtual cases in a virtual case storing portion 12. When the image forming apparatus is operated, detected values of sensors X, Vs and Ds are converted into fuzzy qualitative values, respectively, on the basis of membership functions stored in a membership function generating portion 13. The fuzzy qualitative values are compared with the virtual cases stored in the virtual case storing portion 12, to reason the cause of the fault. Accordingly, any of the virtual cases stored in the virtual case storing portion 12 is selected using the fuzzy qualitative values, thereby to make it possible to accurately specify the fault in a short time.

Image forming apparatus capable of making self-diagnosis

The system of the present invention has a plurality of sensors 1a, 1b and 1c and a system control circuit which includes a case memory portion and a work script memory portion. In response to application of state data from the sensors 1a, 1b and 1c, the system converts the state data into symbolic data. Then the symbolic data is evaluated to judge whether or not a fault exists and to specify a fault symptom. As a result of the judgement, a fault symptom and a fault in the objective machine are determined. Thereafter, cases stored in the case memory portion are retrieved on the basis of the results of the fault diagnosis and a fault simulation. A case which closely resembles the present state of the objective machine is selected. Then, repair work described in the selected case is executed.

Self-diagnosis and self-repair system for image forming apparatus

A system according to the invention has a plurality of sensors, a system control circuit and a plurality of actuators. State data, supplied from the sensors, is compared with characteristic data in the system control circuit. From this comparison, it is judged whether a fault has occurred depending upon whether the state data is relatively lower or higher. If a fault has occurred, fault inference fault is made on the basis of a comparison between qualitative data and fault diagnosis knowledge which are stored in the system control circuit. Then a judgement is made as to which of the elements in an image forming apparatus is abnormal. An actuator operating signal thereafter is generated as a result of this judgement.

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Osaka, Japan

Yoshiki Shimomura