To provide a numerical controller that can detect the position at which the look-ahead blocks used to determine an acceleration/deceleration operation is insufficient in a machining program in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program, a look-ahead blocks calculation unit that calculates a look-ahead blocks, which is the difference between a first sequence number that is the number of a block being executed by the program execution unit and a second sequence number that is the number of a block that is looked ahead by the program look-ahead unit while the machining program is being executed, and an exhaustion block detection unit that detects an exhaustion block, which is a block at which the look-ahead blocks falls below a prescribed value.

To provide a numerical controller that can detect a position in a machining program at which a speed control abnormality is likely to occur due to an insufficient look-ahead blocks that are used to determine an acceleration/deceleration operation, and start a look-ahead processing function from the position in parallel with looking ahead at the machining program from the start of the machining program. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that simultaneously looks ahead at the machining program from different blocks in the machining program in parallel with execution of the machining program and that includes a first program look-ahead unit and a second program look-ahead unit, and a look-ahead allocation unit that divides a storage unit into at least a first region and a second region and instructs the first program look-ahead unit to perform a look-ahead action of storing look-ahead blocks in the first region and instructs the second program look-ahead unit to perform a look-ahead action of storing look-ahead blocks in the second region.

To provide a numerical controller that can detect the position at which the look-ahead blocks used to determine an acceleration/deceleration operation is insufficient in a machining program in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program, a theoretical value calculation unit that calculates theoretical values per block in processing time for the machining program from the feed rate of the machine tool and lengths of minute straight lines that make up the machining path followed by the machine tool, a measured value calculation unit that calculates actually measured values per block in the look-ahead time taken by the program look-ahead unit and the processing time for the machining program while the machining program is being executed, and an abnormal block detection unit that detects an abnormal block that is a block at which the result of subtracting the total of the theoretical values from the total of the actually measured values is more than a prescribed value.

A numerical controller decelerates a spindle feed rate in a bite portion to a bite velocity lower than a commanded feed rate when drilling is carried out and then, after passage through a velocity recovery point where a measured spindle load is made substantially constant, accelerates the spindle feed rate from the bite velocity to the commanded feed rate.

To provide a numerical controller that can detect a position in a machining program at which a speed control abnormality is likely to occur due to an insufficient look-ahead blocks that are used to determine an acceleration/deceleration operation, and supplement the look-ahead blocks at that position in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a required look-ahead blocks setting unit that sets a required look-ahead blocks, which is a look-ahead blocks required to execute a machining program, and an operation limitation unit that compares a look-ahead blocks calculated by a look-ahead blocks calculation unit to the required look-ahead blocks and, if the look-ahead blocks is less than the required look-ahead blocks, limits execution of the machining program until the look-ahead blocks reach the required look-ahead blocks.

A numerical controller decelerates a spindle feed rate in a bite portion to a bite velocity lower than a commanded feed rate when drilling is carried out and then, after passage through a velocity recovery point where a measured spindle load is made substantially constant, accelerates the spindle feed rate from the bite velocity to the commanded feed rate.

To provide a numerical controller that can detect a position in a machining program at which a speed control abnormality is likely to occur due to an insufficient look-ahead blocks that are used to determine an acceleration/deceleration operation, and start a look-ahead processing function from the position in parallel with looking ahead at the machining program from the start of the machining program. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that simultaneously looks ahead at the machining program from different blocks in the machining program in parallel with execution of the machining program and that includes a first program look-ahead unit and a second program look-ahead unit, and a look-ahead allocation unit that divides a storage unit into at least a first region and a second region and instructs the first program look-ahead unit to perform a look-ahead action of storing look-ahead blocks in the first region and instructs the second program look-ahead unit to perform a look-ahead action of storing look-ahead blocks in the second region.

To provide a numerical controller that can detect the position at which the look-ahead blocks used to determine an acceleration/deceleration operation is insufficient in a machining program in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program, a look-ahead blocks calculation unit that calculates a look-ahead blocks, which is the difference between a first sequence number that is the number of a block being executed by the program execution unit and a second sequence number that is the number of a block that is looked ahead by the program look-ahead unit while the machining program is being executed, and an exhaustion block detection unit that detects an exhaustion block, which is a block at which the look-ahead blocks falls below a prescribed value.

To provide a numerical controller that can detect the position at which the look-ahead blocks used to determine an acceleration/deceleration operation is insufficient in a machining program in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program, a theoretical value calculation unit that calculates theoretical values per block in processing time for the machining program from the feed rate of the machine tool and lengths of minute straight lines that make up the machining path followed by the machine tool, a measured value calculation unit that calculates actually measured values per block in the look-ahead time taken by the program look-ahead unit and the processing time for the machining program while the machining program is being executed, and an abnormal block detection unit that detects an abnormal block that is a block at which the result of subtracting the total of the theoretical values from the total of the actually measured values is more than a prescribed value.

To provide a numerical controller that can detect a position in a machining program at which a speed control abnormality is likely to occur due to an insufficient look-ahead blocks that are used to determine an acceleration/deceleration operation, and supplement the look-ahead blocks at that position in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a required look-ahead blocks setting unit that sets a required look-ahead blocks, which is a look-ahead blocks required to execute a machining program, and an operation limitation unit that compares a look-ahead blocks calculated by a look-ahead blocks calculation unit to the required look-ahead blocks and, if the look-ahead blocks is less than the required look-ahead blocks, limits execution of the machining program until the look-ahead blocks reach the required look-ahead blocks.