A system comprising a motor drive device and a control device for the motor drive device, the control device being configured to perform motion control of a moving member via an output shaft of a reducer connected to a motor, the control device comprising: thrust control means configured to generate a position command value (P Mref) for the motor based on an input member thrust command value (F Lref); and motor control means configured to generate a current value (I M) to control the motor based on the motor position command value (P Mref) for the motor, drive device control means configured to generate the member thrust command value (F Lref) input to the thrust control means, based on an input position command value (P Lref) for the moving member, and wherein the motor drive device comprises: a motor encoder configured to detect and output a position (P M) and speed (V M) of an output member that outputs rotation of the motor, and a device encoder configured to obtain and output a rotational position (P L) and speed (V L) of the moving member, and the system comprises thrust measuring means (107, 318) configured to measure and output thrust (F L) occurring at the output shaft of the reducer, wherein the motor control means is configured to execute a first feedback control by generating the current value (I M) according to at least one of the outputs (P M, V M) of the motor encoder, and the thrust control means is configured to execute a second feedback control by generating the motor position command value (P Mref) according to the output (F L) of the thrust measuring means (107, 318), and the drive device control means is configured to execute a third feedback control by generating the member thrust command value (F Lref) in accordance with at least one of the outputs (P L, V L) of the device encoder, and the control device is configured to execute the third feedback control on the input position command value (P Lref) and execute the first feedback control on the motor position command value (P Mref) on which the second feedback control and the third feedback control have been executed. thrust control means configured to generate a position command value (P Mref) for the motor based on an input member thrust command value (F Lref); and motor control means configured to generate a current value (I M) to control the motor based on the motor position command value (P Mref) for the motor, drive device control means configured to generate the member thrust command value (F Lref) input to the thrust control means, based on an input position command value (P Lref) for the moving member, and wherein the motor drive device comprises: a motor encoder configured to detect and output a position (P M) and speed (V M) of an output member that outputs rotation of the motor, and a device encoder configured to obtain and output a rotational position (P L) and speed (V L) of the moving member, and a motor encoder configured to detect and output a position (P M) and speed (V M) of an output member that outputs rotation of the motor, and a device encoder configured to obtain and output a rotational position (P L) and speed (V L) of the moving member, and the system comprises thrust measuring means (107, 318) configured to measure and output thrust (F L) occurring at the output shaft of the reducer, wherein the motor control means is configured to execute a first feedback control by generating the current value (I M) according to at least one of the outputs (P M, V M) of the motor encoder, and the thrust control means is configured to execute a second feedback control by generating the motor position command value (P Mref) according to the output (F L) of the thrust measuring means (107, 318), and the drive device control means is configured to execute a third feedback control by generating the member thrust command value (F Lref) in accordance with at least one of the outputs (P L, V L) of the device encoder, and the control device is configured to execute the third feedback control on the input position command value (P Lref) and execute the first feedback control on the motor position command value (P Mref) on which the second feedback control and the third feedback control have been executed. the motor control means is configured to execute a first feedback control by generating the current value (I M) according to at least one of the outputs (P M, V M) of the motor encoder, and the thrust control means is configured to execute a second feedback control by generating the motor position command value (P Mref) according to the output (F L) of the thrust measuring means (107, 318), and the drive device control means is configured to execute a third feedback control by generating the member thrust command value (F Lref) in accordance with at least one of the outputs (P L, V L) of the device encoder, and the control device is configured to execute the third feedback control on the input position command value (P Lref) and execute the first feedback control on the motor position command value (P Mref) on which the second feedback control and the third feedback control have been executed.