Motor velocity and acceleration determining method, acceleration/deceleration generating method, acceleration/deceleration controlling method, acceleration/deceleration controlling apparatus and motor controlling apparatus

An acceleration/deceleration control apparatus for performing acceleration/deceleration control of a motor to make said motor accelerated/decelerated by changing acceleration of said motor continuously, said apparatus comprising:

• a velocity and acceleration determining means for determining a maximum velocity and a maximum acceleration by selecting and performing one of two processes in accordance with a commanded quantity of motor movement in the case where the commanded quantity of motor movement is smaller than a minimum quantity of motor movement which is required to allow the movement of said motor to reach a predetermined maximum velocity and a predetermined maximum acceleration, said two processes consisting of a process for newly determining a maximum velocity for performing a designated acceleration control on the basis of the commanded quantity of motor movement so as to make a maximum acceleration in an accelerating/decelerating operation equal to the predetermined maximum acceleration, and another process for newly determining a maximum velocity and a maximum acceleration for performing a designated jerk control on the basis of the commanded quantity of motor movement so as to make a maximum absolute value of jerk value, which is differential value of acceleration, not larger than or constantly equal to a predetermined value;
• and
• a reference value generating means for generating and outputting a position reference value on the basis of said maximum velocity and maximum acceleration obtained by said velocity and acceleration determining means.

A motion control method comprising:

• defining an acceleration curve at least partially characterized by an acceleration magnitude parameter, said acceleration magnitude parameter being a maximum operating peak value of said acceleration curve;
• defining a velocity curve at least partially characterized by a velocity magnitude parameter, said velocity magnitude parameter being a maximum operating peak value of said velocity curve;
• determining a minimum critical distance by setting said acceleration magnitude parameter equal to a predetermined maximum acceleration value, setting said velocity magnitude parameter equal to a predetermined maximum velocity value, and defining said minimum critical distance as twice the displacement distance required to reach the velocity of said velocity magnitude parameter along said velocity curve while being accelerated according to said acceleration curve;
• receiving displacement distance instructions including sufficient data for determining a target displacement distance;
• comparing said target displacement distance to said minimum critical distance;
• initiating a motion modification procedure when said target displacement distance is smaller than said minimum critical distance, said motion modification procedure including the execution of a jerk reduction sequence when said target displacement distance is less than a predefined triggering distance, said jerk reduction sequence including:
• a) identifying a maximum operating jerk value as the differential of said acceleration curve evaluated at the upper most limit of said triggering distance;
• b) modifying said acceleration curve by setting said acceleration magnitude parameter equal to a second peak acceleration value, said second peak acceleration value being selected such that the differentiation of said modified acceleration curve maintains a magnitude not larger than said maximum operating jerk value over said predefined triggering distance.

A motion control method comprising:

• defining a continuous acceleration curve having an acceleration stage and a deceleration stage and being at least partially characterized by an acceleration magnitude parameter, said acceleration magnitude parameter being a maximum operating peak value of said acceleration curve;
• defining a velocity curve having a shape generally determined by the integral of said acceleration curve and being at least partially characterized by a velocity magnitude parameter, said velocity magnitude parameter being a maximum operating peak value of said velocity curve;
• determining a minimum critical distance by setting said acceleration magnitude parameter equal to a predetermined maximum acceleration value, setting said velocity magnitude parameter equal to a predetermined maximum velocity value, and defining said minimum critical distance as twice the displacement distance required to reach the velocity of said velocity magnitude parameter along said velocity while following said acceleration curve;
• receiving displacement distance instructions including sufficient data for determining a target displacement distance;
• comparing said target displacement distance to said minimum critical distance;
• initiating a motion modification procedure in response to said target displacement distance being smaller than said minimum critical distance, said motion modification procedure being effective for comparing said target displacement distance to a transition triggering distance and initiating an acceleration control sequence in response to said displacement distance not being smaller than said transition triggering distance and initiating a jerk reduction sequence in response to said displacement distance being smaller than said transition triggering distance, wherein;
• said acceleration control sequence includes:
• i) integrating said velocity curve to create a displacement function defined as a displacement parameter equal to the integral of said velocity curve;
• ii-1) evaluating said displacement function to obtain a displacement measure of the distance required to complete one acceleration stage and one deceleration stage of said acceleration curve;
• ii-2) re-interpreting said displacement measure in terms of at least said displacement parameter, said predetermined maximum acceleration value, and said predetermined maximum velocity value;
• iii) substituting a velocity variable in place of said predetermined maximum velocity value;
• iv) solving said re-interpreted displacement measure in terms of said velocity variable;
• v) setting said displacement parameter equal to said target displacement distance and evaluating for said velocity variable;
• vi) setting said velocity magnitude parameter equal to the evaluated velocity variable;
• and
• said jerk reduction sequence includes:
• a) identifying a maximum operating jerk value as the differential of said acceleration curve evaluated at the upper most limit of said transition triggering distance;
• b) modifying said acceleration curve by setting said acceleration magnitude parameter equal to a second peak acceleration value, said second peak acceleration value being selected such that the differential of said modified acceleration curve maintains a magnitude not larger than said maximum operating jerk value over said predefined triggering distance.

A motion control system for a motion actuating apparatus, said system comprising:

• a first processing block for selecting an acceleration curve at least partially characterized by an acceleration magnitude parameter, said acceleration magnitude parameter being a maximum operating peak value of said acceleration curve;
• a second processing block for selecting a velocity curve at least partially characterized by a velocity magnitude parameter, said velocity magnitude parameter being a maximum operating peak value of said velocity curve;
• a third processing block for determining a minimum critical distance by setting said acceleration magnitude parameter equal to a predetermined maximum acceleration value, setting said velocity magnitude parameter equal to a predetermined maximum velocity value, and determining said minimum critical distance as twice the displacement distance required to reach the velocity of said velocity magnitude parameter along said velocity curve while being accelerated according to said acceleration curve;
• a control input for receiving displacement distance instructions including sufficient data for determining a target displacement distance;
• a comparator block for comparing said target displacement distance to said minimum critical distance;
• a velocity and acceleration determining block for initiating a motion modification procedure when said target displacement distance is smaller than said minimum critical distance, said motion modification procedure including the execution of a jerk reduction sequence when said target displacement distance is less then a predefined triggering distance, said jerk reduction sequence including:
• a) identifying a maximum operating jerk value as the differential of said acceleration curve evaluated at the upper most limit of said triggering distance;
• b) modifying said acceleration curve by setting said acceleration magnitude parameter equal to a second peak acceleration value, said second peak acceleration value being selected such that the differentiation of said modified acceleration curve maintains a magnitude not larger than said maximum operating jerk value over said predefined triggering distance.

A motion control system for a motion actuating apparatus, said system comprising:

• a first processing block selecting a continuous acceleration curve having an acceleration stage and a deceleration stage and being at least partially characterized by an acceleration magnitude parameter, said acceleration magnitude parameter being a maximum operating peak value of said acceleration curve;
• a second processing block defining a velocity curve having a shape generally determined by the integral of said acceleration curve and being at least partially characterized by a velocity magnitude parameter, said velocity magnitude parameter being a maximum operating peak value of said velocity curve;
• a third processing block for determining a minimum critical distance by setting said acceleration magnitude parameter equal to a predetermined maximum acceleration value, setting said velocity magnitude parameter equal to a predetermined maximum velocity value, and defining said minimum critical distance as twice the displacement distance required to reach the velocity of said velocity magnitude parameter along said velocity while following said acceleration curve;
• a control input for receiving displacement distance instructions including sufficient data for determining a target displacement distance;
• a comparator block for comparing said target displacement distance to said minimum critical distance;
• a velocity and acceleration determining block for initiating a motion modification procedure in response to said target displacement distance being smaller than said minimum critical distance, said motion modification procedure being effective for comparing said target displacement distance to a transition triggering distance and initiating an acceleration control sequence in response to said displacement distance not being smaller than said transition triggering distance and initiating a jerk reduction sequence in response to said displacement distance being smaller than said transition triggering distance, wherein;
• said acceleration control sequence includes:
• i) integrating said velocity curve to create a displacement function defined as a displacement parameter equal to the integral of said velocity curve;
• ii-1) evaluating said displacement function to obtain a displacement measure of the distance required to complete one acceleration stage and one deceleration stage of said acceleration curve;
• ii-2) re-interpreting said displacement measure in terms of at least said displacement parameter, said predetermined maximum acceleration value, and said predetermined maximum velocity value;
• iii) substituting a velocity variable in place of said predetermined maximum velocity value;
• iv) solving said re-interpreted displacement measure in terms of said velocity variable;
• v) setting said displacement parameter equal to said target displacement distance and evaluating for said velocity variable;
• vi) setting said velocity magnitude parameter equal to the evaluated velocity variable;
• and
• said jerk reduction sequence includes:
• a) identifying a maximum operating jerk value as the differential of said acceleration curve evaluated at the upper most limit of said transition triggering distance;
• b) modifying said acceleration curve by setting said acceleration magnitude parameter equal to a second peak acceleration value, said second peak acceleration value being selected such that the differential of said modified acceleration curve maintains a magnitude not larger than said maximum operating jerk value over said predefined triggering distance.