Motor control for an exercise machine simulating a weight stack

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor simulate a plurality of weights;
• user input means operatively connected to said control means for permitting a user to operate the exercise machine;
• and
• compensation means operatively connected to said control means for automatically varying said torque output by a compensation factor to compensate for at least a portion of the inertia of said electric motor in response to said control input.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor;
• and
• compensation means operatively connected to said control means for generating a compensation factor for varying said torque output to compensate for at least a portion of the mechanical friction of the exercise machine.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor;
• and
• compensation means operatively connected to said control means for generating a compensation factor for varying said torque output to compensate for at least a portion of the effects of gravity on said user interface.

An exercise machine comprising

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor;
• and
• position means operatively connected to said control means for detecting the position of said user interface;
• compensation means operatively connected to said control means for varying the torque output of said motor by a compensation factor to compensate for at least a portion of the mechanical characteristics of the exercise machine.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor to simulate a weight stack;
• direction means operatively connected to said user interface and said control means for determining whether said user interface is moving in a first or a second direction;
• and
• heavy negative means responsive to said direction means for causing said control means to increase said torque output by a first predetermined amount when said user interface is moving in said second direction.

An exercise machine comprising;

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor;
• and
• test means operatively connected to said user interface and said control means for measuring the strength of a user.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor in order to provide a user opposition force;
• user input means operatively connected to said control means for permitting a user to operate the machine;
• and
• stroke means operatively connected to said control means for permitting the user to set a maximum displacement point of said user interface of a series of repetitions, each having a forward stroke and a return stroke by moving said user interface during the first repetition of said series.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor;
• user input means operatively connected to said control means for permitting the user to operate the exercise machine;
• and
• preposition means operatively connected to said control means for moving said user interface from a rest position to a preset position before initiation of an exercise program.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor to generate a user opposition force;
• user input means operatively connected to said control means for generating and storing in said control means a strength curve including said user opposition forces measured during a selected portion of the displacement of said user interface wherein said control means moves said user interface at a constant rate during the selected portion of the displacement of said user interface during which said user opposition forces are measured;
• and
• exercise means operatively connected to said control means for controlling said torque output to functionally correspond to said strength curve.

An exercise machine comprising:

• a user interface;
• an electric motor;
• linkage means for mechanically connecting said user interface to said electric motor;
• control means operatively connected to said electric motor for controlling the torque output of said electric motor;
• user input means operatively connected to said control means for permitting the user to operate the exercise machine;
• a memory operatively connected to said control means storing a plurality of strength curves wherein said strength curves represent the maximum force that the user is able to exert against said user interface at each point of displacement of said user interface;
• customized strength exercise means operatively connected to said control means and responsive to said user input means for controlling said torque output to functionally correspond to one of said strength curves selected by the user.

In an exercise machine having a user interface engaged by a user to exert a force, means for exerting against the user a counterforce simulating a weight stack comprising:

• a D.C. motor providing a counterforce against the user, said D.C. motor imparting rotation to a shaft coupled to the user interface to transmit the counterforce provided by said D.C. motor;
• means for providing a force signal coupled to said D.C. motor to control the motor to provide said counterforce of a predetermined level;
• means for sensing the speed of the shaft to provide a shaft speed signal proportional thereto;
• inertia correction means responsive to said shaft speed signal for providing an inertia compensation signal to compensate for the inertia of said D.C. motor;
• and
• means for combining said force signal and said inertia compensation signal to provide a control signal coupled to said D.C. motor to control the counterforce exerted thereby.

In an exercise machine having a user interface engaged by a user to exert a force, means for exerting against the user a counterforce simulating a weight stack comprising:

• a D.C. motor providing a counterforce against the user, said D.C. motor imparting rotation to a shaft coupled to the user interface to transmit the counterforce provided by said D.C. motor;
• means for providing a force signal coupled to said D.C. motor to control said D.C. motor to provide said counterforce of a predetermined level;
• means for sensing the speed of the shaft to provide a shaft speed signal proportional thereto;
• friction correction means responsive to said shaft speed signal for providing a friction compensation signal to compensate for the friction of said D.C. motor;
• and
• means for combining said force signal and said friction compensation signal to provide a control signal coupled to said D.C. motor to control the counterforce exerted thereby.

In an exercise machine having a user interface engaged by a user to exert a force, means for exerting against the user a counterforce simulating a weight stack comprising:

• a D.C. motor providing a counterforce against the user, said D.C. motor imparting rotation to a shaft coupled to the user interface to transmit the counterforce provided by said D.C. motor;
• user input means operable by the user to select the level of the counterforce;
• means coupled to said shaft for sensing the displacement of the user interface;
• programmable processing means responsive to said user input means and said displacement sensing means for providing a force signal coupled to said D.C. motor to control said D.C. motor to provide a predetermined counterforce;
• means for sensing the speed of the shaft to provide a shaft speed signal proportional thereto;
• inertia correction means responsive to said shaft speed signal for providing an inertia compensation signal to compensate for the inertia of said D.C. motor;
• means for combining said force signal and said inertia compensation signal to provide a control signal coupled to said D.C. motor to control the counterforce exerted thereby;
• and
• means responsive to said processing means for preventing said inertia compensation signal from being combined with said force signal near zero displacement of said user interface.

In an exercise machine having a user interface engaged by a user to exert a force, means for exerting against the user a counterforce simulating a weight stack comprising:

• a D.C. motor providing a counterforce against the user, said D.C. motor imparting rotation to a shaft coupled to the user interface to transmit the counterforce provided by said D.C. motor;
• user input means operable by the user to select the level of the counterforce;
• means coupled to said shaft for sensing the displacement of the user interface;
• programmable processing means responsive to said user input means and said displacement sensing means for providing a force signal coupled to said D.C. motor to control said D.C. motor to provide a predetermined counterforce;
• means for sensing the speed of the shaft to provide a shaft speed signal proportional thereto;
• friction correction means responsive to said shaft speed signal for providing a friction compensation signal to compensate for the friction of said D.C. motor;
• and
• means for combining said force signal and said friction compensation signal to provide a control signal coupled to said D.C. motor to control the counterforce exerted thereby.

In an exercise machine having a user interface engaged by a user to exert a force, means for exerting against the user a counterforce simulating a weight stack comprising:

• a D.C. motor coupled to the user interface for providing a counterforce against the user;
• input means operable by the user for selecting the level of difficulty of an exercise formed of a plurality of repetitions;
• programmable processing means responsive to said input means for controlling the amount of counterforce provided by said D.C. motor to provide said exercise formed of a progressive phase in which the counterforce is gradually increased from a starting level to a plateau level over a first group of repetitions followed by a plateau phase in which the counterforce is maintained constant at the plateau level over a second group of repetitions followed by a regressive phase in which the counterforce is gradually decreased from the plateau level to the starting level over a third group of repetitions wherein said processing means varies the magnitude of the plateau level counterforce and the number of different progressive level and regressive level repetitions in said exercise in response to the difficulty level selected such that as the level of difficulty increases, the magnitude of the plateau level counterforce and the number of different counterforces applied during the progressive and regressive levels increase.