Patent Description:
Patent Literature <NUM> discloses a system in which a plurality of sensors are connected to an interface unit through respective communication paths, and a detection signal of each of the sensors is transmitted to a host controller or a motor control apparatus via a network that connects the host controller and the motor control apparatus to each other.

Patent Literature <NUM> discloses a system in which a peripheral device that sets a parameter of a motor control apparatus or performs monitoring of the motor control apparatus through a communication unit in the motor control apparatus is connected.

<CIT>
describes a data table stored in a numerical controller that associates motors controlled by the numerical controller with information from sensors used by the motors. When the numerical controller is turned on, the contents of the data table are sent from the numerical control section to the motor control section. The motor control section controls each motor by using information from the sensors associated with the motor in the data table. <CIT> describes an actuator including sensors which are used to detect variables representing the operating state of the actuator and are connected to an evaluation unit associated with the actuator. The evaluation unit is connected to sensors and/or control actuating elements by means of a first data bus. The sensors are used to detect measurable variables representing the operating state of the actuator, and to transmit the same to the evaluation unit. <CIT> discusses automatically setting an axial configuration parameter, using a control system. <CIT> discusses to send and identification code to a software servo circuit without provision of an exclusive signal line for the identification code and to eliminate the need for interconnection between the software servo circuit and an identification code storage means for each setting of a parameter in a parameter automatic setting system for servo motor. <CIT> discusses an actuator that includes sensors, which are used to detect variables representing the operating state of the actuator and are connected to an evaluation unit associated with the actuator. <CIT> discusses a plurality of servo motors for driving a plurality of action axes such as an arm and the like, the rotary encoders for detecting respective rotation positions of the servo motors are provided and output the position information as serial data. <CIT> discusses acontrol device of a power converter for vehicles that controls the power converter based on the output of a current sensor for detecting current flowing through an electric motor is provided with an operation means <NUM> for calculating a current conversion timing in synchronization with a PWM pulse, and a control means with a serial communication means <NUM> for communicating the operation result digitally.

However, there is a problem in that each sensor or each peripheral device is connected to a motor control apparatus, and thus a physical or processing cost tends to increase, in the system in the related art.

The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a motor control apparatus, a motor control method, and a motor control system, in which it is possible to reduce a physical or processing cost.

The invention is defined by the features of the appended independent claims.

According to the present disclosure, it is possible to provide a motor control apparatus, a motor control method, and a motor control system, in which it is possible to reduce a physical or processing cost.

According to the viewpoint of the inventor of the present example, sensing of an operation situation in a motor control system has become more important in recent years. However, if the number of sensors increases, a physical cost for the number of wires and the like and a processing cost for traffic, processing loads, and the like increase. In particular, in a case where sensing is performed in real time, the costs tend to increase.

As a result of intensive research and development to reduce the costs in the motor control system, the inventor of the present example has conceived of a new and unique motor control system. Hereinafter, an example of a motor control system <NUM> according to an example will be described with reference to <FIG>.

In the present disclosure, the motor control system <NUM> according to the example is configured to control a plurality of motors #<NUM> to #<NUM>. As illustrated in <FIG> and <FIG>, the motor control system <NUM> includes a motor control apparatus <NUM>, motors #<NUM> to #<NUM>, a mechanical apparatus (not illustrated), encoders #<NUM> to #<NUM> that detect position information of the motors #<NUM> to #<NUM>, encoders #<NUM> and #<NUM> that detect position information of the mechanical apparatus, and sensors #<NUM> to #<NUM>.

In the example, a case where one motor control apparatus <NUM> that drives three axes of the motors #<NUM> to #<NUM> is provided is described as an example. The present disclosure can be applied to a case where a plurality of motor control apparatuss are provided, or a motor control apparatus that drives one axis and the like.

The motor control apparatus <NUM> is configured to control the motors #<NUM> to #<NUM>. Specifically, the motor control apparatus <NUM> is a device including a computer that controls an amplifier unit that outputs a current, a voltage, and the like to the motors #<NUM> to #<NUM>. That is, the motors #<NUM> to #<NUM> are configured to rotate in accordance with the voltage or the current applied from the motor control apparatus <NUM>.

Generally, the motor control apparatus <NUM> that controls a servomotor is called as a servo-controller, a servo-amplifier, or the like. The motor control apparatus <NUM> may be a device configured to control the motor <NUM>.

Specifically, as illustrated in <FIG>, the motor control apparatus <NUM> includes inverter (INV) circuits #<NUM> to #<NUM> including amplifier units, motor control units #<NUM> to #<NUM> that respectively control the motors #<NUM> to #<NUM>, an encoder-sensor communication transmission-and-reception management unit <NUM>, a non-volatile memory <NUM>, and physical interfaces (IFs) #<NUM> to #<NUM>.

The amplifier unit is a power converter configured to supply a current or a voltage to the motors #<NUM> to #<NUM> based on a torque command from the motor control units #<NUM> to #<NUM>, by switching (PWM control) of the inverter (INV) circuits #<NUM> to #<NUM>.

Here, as illustrated in <FIG>, each of the motor control units #<NUM> to #<NUM> includes a motor control calculation unit <NUM>, an encoder logical-axis interface <NUM>, an external encoder logical-axis interface <NUM>, and a sensor logical-axis interface <NUM>.

The motor control calculation unit <NUM> is configured to receive a command (position command and the like) from a host device and performs calculation for controlling positions, speeds, torques, and the like of the motors #<NUM> to #<NUM>.

The encoder logical-axis interface <NUM> is configured to read out constants of the motors #<NUM> to #<NUM> corresponding to the motor control units #<NUM> to #<NUM> to which the encoder logical-axis interface <NUM> belongs, and identification information (encoder ID information) of the encoders #<NUM> to #<NUM> corresponding to the motors #<NUM> to #<NUM>, based on a mapping table which is managed by the encoder-sensor communication transmission-and-reception management unit <NUM> and is stored in the non-volatile memory <NUM>.

The encoder logical-axis interface <NUM> is configured to acquire position information of the motors #<NUM> to #<NUM> corresponding to the motor control units #<NUM> to #<NUM> to which the encoder logical-axis interface <NUM> belongs from the encoder #<NUM> to #<NUM> corresponding to the motors #<NUM> to #<NUM>, based on the mapping table which is managed by the encoder-sensor communication transmission-and-reception management unit <NUM> and is stored in the non-volatile memory <NUM>.

Specifically, in the example, the encoder logical-axis interface <NUM> in the motor control unit #<NUM> is configured to acquire the motor constant or the position information of the motor #<NUM> and the encoder ID information of the encoder #<NUM> from the encoder-sensor communication transmission-and-reception management unit <NUM>.

Similarly, the encoder logical-axis interface <NUM> in the motor control unit #<NUM> is configured to acquire the motor constant or the position information of the motor #<NUM> and the encoder ID information of the encoder #<NUM> from the encoder-sensor communication transmission-and-reception management unit <NUM>.

The external encoder logical-axis interface <NUM> is configured to read out identification information (external encoder ID information) of the external encoders #<NUM> and #<NUM> corresponding to the motors #<NUM> and #<NUM> corresponding to the motor control units #<NUM> to #<NUM> to which the external encoder logical-axis interface <NUM> belongs, based on the mapping table which is managed by the encoder-sensor communication transmission-and-reception management unit <NUM> and is stored in the non-volatile memory <NUM>.

The external encoder logical-axis interface <NUM> is configured to acquire the position information of the mechanical apparatus that is driven by the motors #<NUM> and #<NUM> corresponding to the motor control units #<NUM> and #<NUM> to which the external encoder logical-axis interface <NUM> belongs, from the external encoders #<NUM> and #<NUM> corresponding to the mechanical apparatus that is driven by the motors #<NUM> and #<NUM>. The acquisition is performed based on the mapping table which is managed by the encoder-sensor communication transmission-and-reception management unit <NUM> and is stored in the non-volatile memory <NUM>.

Specifically, in the example, the external encoder logical-axis interface <NUM> in the motor control unit #<NUM> is configured to acquire position information of the mechanical apparatus that is driven by the motor #<NUM> or encoder ID information of the encoder #<NUM>, from the encoder-sensor communication transmission-and-reception management unit <NUM>.

Similarly, the external encoder logical-axis interface <NUM> in the motor control unit #<NUM> is configured to acquire position information of the mechanical apparatus that is driven by the motor #<NUM> or encoder ID information of the encoder #<NUM>, from the encoder-sensor communication transmission-and-reception management unit <NUM>.

The sensor logical-axis interface <NUM> is configured to read out identification information (sensor ID information) of the sensors #<NUM> to #<NUM> corresponding to the motor control units #<NUM> to #<NUM> to which the sensor logical-axis interface <NUM> belongs, based on the mapping table managed by the encoder-sensor communication transmission-and-reception management units <NUM>.

The sensor logical-axis interface <NUM> is configured to read out sensor data of the sensors #<NUM> to #<NUM> corresponding to the motor control units #<NUM> to #<NUM> to which the sensor logical-axis interface <NUM> belongs, based on the mapping table managed by the encoder-sensor communication transmission-and-reception management units <NUM>. Here, the sensor data includes ON/OFF information and the like of the sensor, for example.

The encoder-sensor communication transmission-and-reception management unit <NUM> is configured to manage communications with the encoders #<NUM> to #<NUM> or the sensors #<NUM> to #<NUM>. Here, the encoder-sensor communication transmission-and-reception management unit <NUM> is configured to manage the mapping table illustrated in <FIG>.

The mapping table is configured to be stored in a non-volatile memory such as an electrically erasable programmable read only memory (EEPROM).

In the example of a first axis in <FIG>, the identification information of the encoder #<NUM> and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the encoder logical-axis interface <NUM> of the motor control unit #<NUM>, the physical interface #<NUM> (ch3), a communication address Addr. <NUM>, and the identification information of the encoder #<NUM> are associated with each other.

Similarly, in the example of the first axis in <FIG>, the identification information of the sensor #<NUM> and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the sensor logical-axis interface <NUM> of the motor control unit #<NUM>, a physical interface #<NUM> (ch1), the communication address Addr. <NUM>, and the identification information of the sensor #<NUM> are associated with each other.

In the example of the first axis in <FIG>, the external encoder is not provided. Thus, identification information of the external encoder and the motor control unit #<NUM> (motor #<NUM>) are not associated with each other.

In the example of a second axis in <FIG>, the identification information of the encoder #<NUM> and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the encoder logical-axis interface <NUM> of the motor control unit #<NUM>, the physical interface #<NUM> (ch3), a communication address Addr. <NUM>, and the identification information of the encoder #<NUM> are associated with each other.

Similarly, in the example of the second axis in <FIG>, the identification information of the encoder #<NUM> (external encoder) and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the external encoder logical-axis interface <NUM> of the motor control unit #<NUM>, a physical interface #<NUM> (ch2), the communication address Addr. <NUM>, and the identification information of the encoder #<NUM> are associated with each other.

Similarly, in the example of the second axis in <FIG>, the identification information of the sensor #<NUM> and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the sensor logical-axis interface <NUM> of the motor control unit #<NUM>, the physical interface #<NUM> (ch1), the communication address Addr. <NUM>, and the identification information of the sensor #<NUM> are associated with each other.

In the example of a third axis in <FIG>, the identification information of the encoder #<NUM> and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the encoder logical-axis interface <NUM> of the motor control unit #<NUM>, the physical interface #<NUM> (ch3), the communication address Addr. <NUM>, and the identification information of the encoder #<NUM> are associated with each other.

Similarly, in the example of the third axis in <FIG>, the identification information of the encoder #<NUM> (external encoder) and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the external encoder logical-axis interface <NUM> of the motor control unit #<NUM>, the physical interface #<NUM> (ch2), the communication address Addr. <NUM>, and the identification information of the encoder #<NUM> are associated with each other.

Similarly, in the example of the third axis in <FIG>, the identification information of the sensor #<NUM> and the motor control unit #<NUM> (motor #<NUM>) are associated with each other. Specifically, the sensor logical-axis interface <NUM> of the motor control unit #<NUM>, the physical interface #<NUM> (ch1), the communication address Addr. <NUM>, and the identification information of the sensor #<NUM> are associated with each other.

The mapping table may be set in advance by a user, and the setting details may be preserved in the non-volatile memory <NUM> of the motor control apparatus <NUM>.

For example, the encoder-sensor communication transmission-and-reception management unit <NUM> is configured to assign unique communication addresses to the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> based on the above-described mapping table.

The encoder-sensor communication transmission-and-reception management unit <NUM> is configured to transfer the constants of the motors #<NUM> to #<NUM>, the identification information of the encoders #<NUM> to #<NUM>, the identification information of the external encoders #<NUM> and #<NUM>, and the identification information of the sensors #<NUM> to #<NUM> to the corresponding encoder logical-axis interface <NUM>, the corresponding external encoder logical-axis interface <NUM>, or the corresponding sensor logical-axis interface <NUM>, based on the above-described mapping table.

Similarly, the encoder-sensor communication transmission-and-reception management unit <NUM> is configured to transfer the position information of the motors #<NUM> to #<NUM>, the position information of the mechanical apparatus that is driven by the motors #<NUM> and #<NUM>, and the sensor data of the sensors #<NUM> to #<NUM> to the corresponding encoder logical-axis interface <NUM>, the corresponding external encoder logical-axis interface <NUM>, or the corresponding sensor logical-axis interface <NUM>, based on the above-described mapping table.

The physical interfaces #<NUM> to #<NUM> are configured to perform processing of transmitting and receiving data to and from devices (motor control apparatus, encoder, external encoder, sensor, and the like) other than the motor control apparatus <NUM> to which the physical interfaces #<NUM> to #<NUM> belong.

Here, the encoders #<NUM> to #<NUM> and the external encoders #<NUM> and #<NUM> may be optical encoders or magnetic encoders, for example. The encoders #<NUM> to #<NUM> and the external encoders #<NUM> and #<NUM> are configured to transmit the position information of the motors #<NUM> to #<NUM> or the position information of the mechanical apparatus that is driven by the motor #<NUM> or #<NUM>, to the motor control apparatus <NUM>.

In the example, a case using the encoders #<NUM> to #<NUM> and the external encoders #<NUM> and #<NUM> as the position detector is described as an example. The present disclosure can be applied to a case using a sensor (for example, resolver) capable of detecting the position information of the motors #<NUM> to #<NUM> and the position information of the mechanical apparatus that is driven by the motors #<NUM> and #<NUM>. Here, the encoders #<NUM> to #<NUM> and the external encoders #<NUM> and #<NUM> may be linear scales (linear encoders) used in a case where the motors #<NUM> to #<NUM> are linear motors or linear scales (linear encoders) attached to the mechanical apparatus.

The motors #<NUM> to #<NUM> may be rotary motors or linear motors. Here, in a case where the motors #<NUM> to #<NUM> are rotary motors, the above-described position information indicates a rotation angle. In a case where the motors #<NUM> to #<NUM> are linear motors, the above-described position information indicates a linear position.

In the example, a case where the encoders #<NUM> to #<NUM> and the external encoders #<NUM> and #<NUM> are provided is described as an example. The present disclosure can be applied to a case where there is no limitation to the number of external encoders (for example, <NUM>, <NUM>, or three or more).

The mechanical apparatus is configured to be driven by the motors #<NUM> to #<NUM>. For example, a robot corresponds to the mechanical apparatus. For example, in the example, the motors #<NUM> to #<NUM> are configured to respectively drive the first axis to the third axis of a three-axis robot as the mechanical apparatus.

In an embodiment not forming part of the invention, the sensors #<NUM> to #<NUM> are configured to detect information (sensor data) relating to at least any one of the motors #<NUM> to #<NUM> and the mechanical apparatus configured to be driven by the motors #<NUM> to #<NUM>. For example, a temperature sensor, a pressure sensor, a torque sensor, a vibration sensor, a limit switch sensor, a touch sensor, and an I/O device are assumed as the plurality of sensors #<NUM> to #<NUM>.

The temperature sensor is a sensor configured to detect the temperature of at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM> or the temperature in the vicinity of the mechanical apparatus or the motors #<NUM> to #<NUM>. For example, a temperature measuring resistor type sensor or a thermocouple type sensor may be used as the temperature sensor.

The pressure sensor is a sensor configured to detect the pressure of at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM> or the pressure in the vicinity of the mechanical apparatus or the motors #<NUM> to #<NUM>. The pressure sensor is configured to measure the pressure with a pressure-sensitive element through a diaphragm (a stainless steel diaphragm, a silicon diaphragm, or the like) and to convert the measured pressure into an electrical signal and output the electrical signal.

The torque sensor is a sensor configured to detect a torque of at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM>. For example, the torque sensor may be a non-contact type torque sensor or a contact type torque sensor.

In this embodiment not forming part of the invention, the information (sensor data) relating to at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM> means information which is not position information of the motors #<NUM> to #<NUM> among types of information regarding the state of at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM>. The information relating to at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM> may be, for example, information which can be detected by the sensors #<NUM> to #<NUM>.

For example, the information relating to at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM> is information of the torques of the motors #<NUM> to #<NUM>, the temperatures of the motors #<NUM> to #<NUM>, a position of an object such as an arm, which is moved by the motors #<NUM> to #<NUM>, pressure on the object, or the state (for example, temperature or ON/OFF information) of the sensors #<NUM> to #<NUM> that detect the above items.

The association information regarding at least any one of the mechanical apparatus and the motors #<NUM> to #<NUM> is used for an output control of the motors #<NUM> to #<NUM> or for adjusting a control parameter or is used for determining whether or not a problem occurs in the motors #<NUM> to #<NUM> or predicting lifespans (remaining periods) of the motors #<NUM> to #<NUM>.

Here, as illustrated in <FIG>, in the motor control system <NUM> according to the example, the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> are connected under a control of the motor control apparatus <NUM>.

Specifically, in the motor control system <NUM> according to the example, as illustrated in <FIG>, the encoder #<NUM> and the sensor #<NUM> are connected in series under a control of the first axis of the motor control apparatus <NUM>.

Similarly, in the motor control system <NUM> according to the example, as illustrated in <FIG>, the encoder #<NUM>, the external encoder #<NUM>, and the sensor #<NUM> are connected in series under a control of the second axis of the motor control apparatus <NUM>.

Further, in the motor control system <NUM> according to the example, as illustrated in <FIG>, the encoder #<NUM>, the external encoder #<NUM>, and the sensor #<NUM> are connected in series under a control of the third axis of the motor control apparatus <NUM>.

The case where the three sensors #<NUM> to #<NUM> are provided is described as an example not forming part of the invention.

Here, the motor control apparatus <NUM> is configured to automatically acquire the identification information of the encoders #<NUM> to #<NUM>, the identification information of the external encoders #<NUM> and #<NUM>, and the identification information of the sensors #<NUM> to #<NUM> and to store the identification information and the motor control units #<NUM> to #<NUM> in the non-volatile memory <NUM> in association with each other.

Specifically, the encoder-sensor communication transmission-and-reception management unit <NUM> in the motor control apparatus <NUM> is configured to automatically acquire the identification information of the sensors #<NUM> to #<NUM> through the physical interface #<NUM> and to store the identification information and the motor control units #<NUM> to #<NUM> in the non-volatile memory <NUM> in association with each other.

Similarly, the encoder-sensor communication transmission-and-reception management unit <NUM> in the motor control apparatus <NUM> is configured to automatically acquire the identification information of the encoders #<NUM> and #<NUM> through the physical interface #<NUM> and to store the identification information and the motor control units #<NUM> and #<NUM> in the non-volatile memory <NUM> in association with each other.

Similarly, the encoder-sensor communication transmission-and-reception management unit <NUM> in the motor control apparatus <NUM> is configured to automatically acquire the identification information of the encoders #<NUM> to #<NUM> through the physical interface #<NUM> and to store the identification information and the motor control units #<NUM> to #<NUM> in the non-volatile memory <NUM> in association with each other.

The motor control apparatus <NUM> may be configured to compare the identification information of the encoders #<NUM> to #<NUM>, the identification information of the external encoders #<NUM> and #<NUM>, or the identification information of the sensors #<NUM> to #<NUM>, which have been acquired from the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> connected under the control of the motor control apparatus <NUM>, to the identification information of the encoders #<NUM> to #<NUM>, the identification information of the external encoders #<NUM> and #<NUM>, or the identification information of the sensors #<NUM> to #<NUM>, which have been stored in the non-volatile memory <NUM>. Thus, the motor control apparatus <NUM> may be configured to check at least one of whether the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> operate as the above-described association and whether a connection configuration of the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> is not changed.

Further, the motor control apparatus <NUM> may be configured to instruct the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, or the sensors #<NUM> to #<NUM> to perform setting. For example, the motor control apparatus <NUM> is configured to instruct the encoders #<NUM> to #<NUM> and the external encoders #<NUM> and #<NUM> to set an origin, set a multiturn limit, reset a multiturn, and the like.

Here, the origin is a zero point in a coordinate system of the mechanical apparatus that is driven by the motors #<NUM> to #<NUM>. For example, origin setting means that the origin is set to any position by a predetermined parameter in a case where an absolute linear encoder is used as the position detector. The user of the motor control apparatus <NUM> can set the predetermined parameter to be any value in accordance with the used mechanical apparatus.

The multiturn limit is used, for example, for controlling the position of a rotating body such as a turntable by using an absolute encoder as the position detector. In a case where a mechanical apparatus that moves the turntable only in one direction is assumed, the turntable rotates only in the one direction. Thus, the number of rotations of the turntable may exceed the upper limit of the number of rotations that can be counted by the absolute encoder. The multiturn limit is a parameter used such that fractions do not occur in an integer ratio relationship of the number of rotations of the motor and the number of rotations of the turntable, in this case. The user of the motor control apparatus <NUM> can set the parameter to any value in accordance with the mechanical apparatus to be used.

The multiturn reset means initialization (initialization of multiturn data) of the absolute value encoder to be used.

The motor control apparatus <NUM> is configured to start the motor control apparatus <NUM> again in a case where the above-described setting is performed and to check at least one of whether or not the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, or the sensors #<NUM> to #<NUM> operate as with the setting and whether or not predetermined operations of the motors #<NUM> to #<NUM> controlled by the motor control apparatus <NUM> are possible.

The motor control apparatus <NUM> may be configured to check at least one of whether or not the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, or the sensors #<NUM> to #<NUM> operate as with the setting and whether or not predetermined operations of the motors #<NUM> to #<NUM> controlled by the motor control apparatus <NUM> are possible, in a case where the power of the motor control apparatus <NUM> is put again, or in a case where the motor control apparatus <NUM> is restored (alarm reset) from an abnormal state or changes a parameter that requires power on (that is, in a case where the motor control apparatus <NUM> is software-reset).

Next, an example of an operation of the motor control apparatus <NUM> constituting the motor control system <NUM> according to the example will be described with reference to <FIG>.

As illustrated in <FIG>, in Step S101, the motor control apparatus <NUM> automatically acquires and displays the identification information of the encoders #<NUM> to #<NUM>, the identification information of the external encoders #<NUM> and #<NUM>, and the identification information of the sensors #<NUM> to #<NUM>, through the physical interfaces #<NUM> to #<NUM>.

In Step S102, the motor control apparatus <NUM> sets association between the identification information and the logical-axis interfaces <NUM> to <NUM>. In Step S103, the motor control apparatus <NUM> generates the mapping table (see <FIG>) and stores the mapping table in the non-volatile memory <NUM>.

As illustrated in <FIG>, if the power is put into the motor control apparatus <NUM> in Step S201, the motor control apparatus <NUM> automatically searches for the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> connected under the control of the physical interfaces #<NUM> to #<NUM> of the motor control apparatus <NUM> in Step S202.

In Step S203, the motor control apparatus <NUM> compares the number of the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> connected under the control of the physical interface #<NUM> to #<NUM> of the motor control apparatus <NUM> to the managed number (number registered in the mapping table).

In a case where both the numbers are equal to each other, the process proceeds to Step S204. In a case where both the numbers are not equal to each other, the process proceeds to Step S206.

In Step S204, the motor control apparatus <NUM> acquires the identification information of the encoders #<NUM> to #<NUM>, the external encoders #<NUM> and #<NUM>, and the sensors #<NUM> to #<NUM> connected under the control of the physical interface #<NUM> to #<NUM> of the motor control apparatus <NUM>.

In Step S205, the motor control apparatus <NUM> compares the acquired identification information to the managed identification information (identification information registered in the mapping table).

In a case where both pieces of identification information coincide with each other, the process proceeds to Step S207. In a case where both the pieces of identification information do not coincide with each other, the process proceeds to Step S206.

In Step S206, the motor control apparatus <NUM> displays abnormality and performs a notification of the abnormality. In Step S207, the motor control apparatus <NUM> performs a normal operation.

Claim 1:
A motor control system comprising:
a motor control apparatus (<NUM>) including a plurality of motor control units configured to respectively control motors; and
a plurality of position detectors connected in series under a control of the motor control apparatus and configured to detect position information of the respective motors, wherein
the motor control apparatus is configured:
to automatically acquire each identification information of the plurality of position detectors,
to store the acquired identification information in association with the plurality of motor control units in a non-volatile memory (<NUM>).