Control device, method, and non-transitory computer readable storage medium for system

A control device adapted to a system including a rotary electric machine, a DC power supply, an inverter and a wheel sensor, the rotary electric machine including a stator and a stator winding, the inverter electrically connecting the stator winding to the DC power supply, the system configured to rotate a wheel of a vehicle by transmitting rotational power of the rotary electric machine to the wheel, the wheel sensor having a first sensor unit and a second sensor unit, the first sensor unit being fixed to a wheel of a vehicle, the first sensor unit configured to be rotated along with a rotation of the wheel around a rotational axis extending in a predetermined axial direction, the second sensor unit being fixed to a base portion and disposed at a position facing the first sensor unit in the predetermined axial direction, a detection target unit being one of the first sensor unit and the second sensor unit, the detection target unit having an annular shape centered on the rotational axis, a receiving coil being another of the first sensor unit and the second sensor unit, the receiving coil configured to output an AC voltage signal having an amplitude that is varied with a relative displacement of the detection target unit to the receiving coil, the control device comprising:

• at least one of (i) a circuit and (ii) a processor with a memory storing computer program code executable by the processor, the at least one of the circuit and the processor configured to cause the control device to carry out:
• calculating, based on the AC voltage signal output from the receiving coil, a lateral force, a longitudinal force and a vertical force that act on the wheel, the vertical force being exerted from a road surface on which the vehicle is travelling;
• calculating a parameter to be used in slip suppression control of the vehicle, wherein
• the calculating of the parameter includes calculating, as the parameter, an allowable upper limit value of the lateral force acting on the wheel and an allowable upper limit value of the longitudinal force acting on the wheel such that the condition is met, the condition being met when a resultant force does not exceed a friction circle of the wheel, based on the calculated lateral force, the calculated longitudinal force, and the calculated vertical force, the resultant force being a vector sum of the lateral force and the longitudinal force,
• the at least one of the circuit and the processor is further configured to cause the control device to carry out:
• adjusting a torque of the rotary electric machine to a commanded value by executing switching control of the inverter;
• determining whether the resultant force exceeds the friction circle based on the calculated allowable upper limit value of the longitudinal force;
• and
• adjusting the torque of the rotary electric machine to a limited value lower than the commanded value on a condition that the control device determines that the resultant force exceeds the friction circle, by executing the switching control,
• the system includes a higher-level controller configured to be communicatively connected to the at least one of the circuit and the processor and to transmit the commanded value to the at least one of the circuit and the processor, and
• the at least one of the circuit and the processor is further configured to cause the control device to carry out:
• receiving the commanded value from the higher-level controller;
• executing a comparison between the received commanded value and the limited value;
• and
• transmitting a result of the comparison to the higher-level controller.

A non-transitory computer readable storage medium storing a program adapted to a system including a wheel sensor, the wheel sensor having a first sensor unit and a second sensor unit, the first sensor unit being fixed to a wheel of a vehicle, the first sensor unit configured to be rotated along with a rotation of the wheel around a rotational axis extending in a predetermined axial direction, the second sensor unit being fixed to a base portion and disposed at a position facing the first sensor unit in the predetermined axial direction, a detection target unit being one of the first sensor unit and the second sensor unit, the detection target unit having an annular shape centered on the rotational axis, a receiving coil being another of the first sensor unit and the second sensor unit, the receiving coil configured to output an AC voltage signal having an amplitude that is varied with a relative displacement of the detection target unit to the receiving coil, the program comprising instructions configured to, when executed by at least one processor, cause the at least one processor to carry out:

• calculating, based on the AC voltage signal output from the receiving coil, a lateral force, a longitudinal force and a vertical force that act on the wheel, the vertical force being exerted from a road surface on which the vehicle is travelling;
• and
• calculating a parameter to be used in slip suppression control of the vehicle, wherein
• the calculating of the parameter includes calculating, as the parameter, an allowable upper limit value of the lateral force acting on the wheel and an allowable upper limit value of the longitudinal force acting on the wheel such that the condition is met, the condition being met when a resultant force does not exceed a friction circle of the wheel, based on the calculated lateral force, the calculated longitudinal force, and the calculated vertical force, the resultant force being a vector sum of the lateral force and the longitudinal force,
• the system includes:
• a mechanical brake device that is configured to apply a braking force to the wheel of the vehicle;
• a braking force controller that is configured to control the braking force applied by the mechanical brake device;
• a driving controller that is configured to generate a driving plan of the vehicle;
• and
• a higher-level controller that is configured to function as a supervisory controller over the braking force controller and the driving controller, and
• the instructions are further configured to, when executed by the at least one processor, cause the at least one processor to carry out:
• communicating with at least one of the braking force controller, the driving controller, or the higher-level controller;
• and
• transmitting the calculated parameter to at least one of the braking force controller, the driving controller, or the higher-level controller.

A control method for a system including a wheel sensor, the wheel sensor having a first sensor unit and a second sensor unit, the first sensor unit being fixed to a wheel of a vehicle, the first sensor unit configured to be rotated along with a rotation of the wheel around a rotational axis extending in a predetermined axial direction, the second sensor unit being fixed to a base portion and disposed at a position facing the first sensor unit in the predetermined axial direction, a detection target unit being one of the first sensor unit and the second sensor unit, the detection target unit having an annular shape centered on the rotational axis, a receiving coil being another of the first sensor unit and the second sensor unit, the receiving coil configured to output an AC voltage signal having an amplitude that is varied with a relative displacement of the detection target unit to the receiving coil, the control method comprising:

• calculating, based on the AC voltage signal output from the receiving coil, a lateral force, a longitudinal force and a vertical force that act on the wheel, the vertical force being exerted from a road surface on which the vehicle is travelling;
• and
• calculating a parameter to be used in slip suppression control of the vehicle, wherein
• the calculating of the parameter includes calculating, as the parameter, an allowable upper limit value of the lateral force acting on the wheel and an allowable upper limit value of the longitudinal force acting on the wheel such that the condition is met, the condition being met when a resultant force does not exceed a friction circle of the wheel, based on the calculated lateral force, the calculated longitudinal force, and the calculated vertical force, the resultant force being a vector sum of the lateral force and the longitudinal force,
• the system includes:
• a mechanical brake device that is configured to apply a braking force to the wheel of the vehicle;
• a braking force controller that is configured to control the braking force applied by the mechanical brake device;
• a driving controller that is configured to generate a driving plan of the vehicle;
• and
• a higher-level controller that is configured to function as a supervisory controller over the braking force controller and the driving controller, the control method further comprising:
• communicating with at least one of the braking force controller, the driving controller, or the higher-level controller;
• and
• transmitting the calculated parameter to at least one of the braking force controller, the driving controller, or the higher-level controller.

A non-transitory computer readable storage medium storing a program adapted to a system including a rotary electric machine, a DC power supply, an inverter, and a wheel sensor, the rotary electric machine including a stator and a stator winding, the inverter electrically connecting the stator winding to the DC power supply, the system configured to rotate a wheel of a vehicle by transmitting rotational power of the rotary electric machine to the wheel, the wheel sensor having a first sensor unit and a second sensor unit, the first sensor unit being fixed to the wheel of the vehicle, the first sensor unit configured to be rotated along with a rotation of the wheel around a rotational axis extending in a predetermined axial direction, the second sensor unit being fixed to a base portion and disposed at a position facing the first sensor unit in the predetermined axial direction, a detection target unit being one of the first sensor unit and the second sensor unit, the detection target unit having an annular shape centered on the rotational axis, a receiving coil being another of the first sensor unit and the second sensor unit, the receiving coil configured to output an AC voltage signal having an amplitude that is varied with a relative displacement of the detection target unit to the receiving coil, the program comprising instructions configured to, when executed by at least one processor, cause the at least one processor to carry out:

• calculating, based on the AC voltage signal output from the receiving coil, a lateral force, a longitudinal force and a vertical force that act on the wheel, the vertical force being exerted from a road surface on which the vehicle is travelling;
• calculating a parameter to be used in slip suppression control of the vehicle, wherein
• the calculating of the parameter includes calculating, as the parameter, an allowable upper limit value of the lateral force acting on the wheel and an allowable upper limit value of the longitudinal force acting on the wheel such that the condition is met, the condition being met when a resultant force does not exceed a friction circle of the wheel, based on the calculated lateral force, the calculated longitudinal force, and the calculated vertical force, the resultant force being a vector sum of the lateral force and the longitudinal force,
• the instructions are further configured to, when executed by the at least one processor, cause the at least one processor to carry out:
• adjusting a torque of the rotary electric machine to a commanded value by executing switching control of the inverter;
• determining whether the resultant force exceeds the friction circle based on the calculated allowable upper limit value of the longitudinal force;
• and
• adjusting the torque of the rotary electric machine to a limited value lower than the commanded value on a condition that the control device determines that the resultant force exceeds the friction circle, by executing the switching control,
• the system includes a higher-level controller configured to be communicatively connected to the at least one of the circuit and the processor and to transmit the commanded value to the at least one of the circuit and the processor, and
• the instructions are further configured to, when executed by the at least one processor, cause the at least one processor to carry out:
• receiving the commanded value from the higher-level controller;
• executing a comparison between the received commanded value and the limited value;
• and
• transmitting a result of the comparison to the higher-level controller.

A control method for a system including a rotary electric machine, a DC power supply, an inverter, and a wheel sensor, the rotary electric machine including a stator and a stator winding, the inverter electrically connecting the stator winding to the DC power supply, the system configured to rotate a wheel of a vehicle by transmitting rotational power of the rotary electric machine to the wheel, the wheel sensor having a first sensor unit and a second sensor unit, the first sensor unit being fixed to a wheel of a vehicle, the first sensor unit configured to be rotated along with a rotation of the wheel around a rotational axis extending in a predetermined axial direction, the second sensor unit being fixed to a base portion and disposed at a position facing the first sensor unit in the predetermined axial direction, a detection target unit being one of the first sensor unit and the second sensor unit, the detection target unit having an annular shape centered on the rotational axis, a receiving coil being another of the first sensor unit and the second sensor unit, the receiving coil configured to output an AC voltage signal having an amplitude that is varied with a relative displacement of the detection target unit to the receiving coil, the control method comprising:

• calculating, based on the AC voltage signal output from the receiving coil, a lateral force, a longitudinal force and a vertical force that act on the wheel, the vertical force being exerted from a road surface on which the vehicle is travelling;
• calculating a parameter to be used in slip suppression control of the vehicle, wherein
• the calculating of the parameter includes calculating, as the parameter, an allowable upper limit value of the lateral force acting on the wheel and an allowable upper limit value of the longitudinal force acting on the wheel such that the condition is met, the condition being met when a resultant force does not exceed a friction circle of the wheel, based on the calculated lateral force, the calculated longitudinal force, and the calculated vertical force, the resultant force being a vector sum of the lateral force and the longitudinal force, the control method further comprising:
• adjusting a torque of the rotary electric machine to a commanded value by executing switching control of the inverter;
• determining whether the resultant force exceeds the friction circle based on the calculated allowable upper limit value of the longitudinal force;
• and
• adjusting the torque of the rotary electric machine to a limited value lower than the commanded value on a condition that the control device determines that the resultant force exceeds the friction circle, by executing the switching control, wherein
• the system includes a higher-level controller configured to transmit the commanded value, the control method further comprising:
• receiving the commanded value from the higher-level controller;
• executing a comparison between the received commanded value and the limited value;
• and
• transmitting a result of the comparison to the higher-level controller.