Power assisting system

• US 8,560,156 B2
• Filed: 11/18/2009
• Issued: 10/15/2013
• Est. Priority Date: 09/15/2009
• Status: Expired due to Fees

• Current Assignee: KPIT Technologies Ltd.
• Original Assignee: KPIT Cummins Infosystems Limited
• Inventors: Kshatriya, Tejas Krishna
• Primary Examiner(s): Cheung, Mary
• Application Number:
  US13/496,161
• Publication Number:
  US 20120197473A1
• Time in Patent Office: 1,427 Days
• Field of Search: 701/22, 701/83, 701/84, 701/93, 180/65.21, 180/65.285, 180/65.29, 180/165
• US Class Current: 701/22
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

The present invention relates to a modular power assisting system. In particular the present invention relates to a modular electric power assisting system that is adaptable to a vehicle/engine driven system so as to be operated/powered by electric system and/or its original power system. The synergistic combination of the motor system; motor control system and energy storage device coupled to the regenerative braking system of the present invention enables the power assisting system of the present invention to adapt to the vehicle/engine without involving substantial modifications in engine, power train, drive train and vehicle. The engine and electric motor exploits advantages of each of the power source based on the operating conditions of the vehicle/engine driven system by selectively responding to the engine'"'"'s power demands so as to enhance fuel efficiency, reduce undesirable emissions and provide better drivability.

Claims

1. A modular power assisting system for a vehicle comprising:

a motor system configured to assist an engine of a vehicle, wherein the motor system comprises a motor, a motor transmission system for coupling the motor to the engine, and a mounting structure;

a motor control system configured to provide at least one of speed control or torque control for the motor system;

an energy storage system comprising an energy storage device including at least one battery, a battery charging system configured to charge the energy storage device using the motor, and a regenerative braking system that includes at least one solid state power device and is configured to utilize a reduction in kinetic energy of at least one of the vehicle or the engine to charge the energy storage device; and

a sensor system configured to provide an interface between the motor control system and sensors within the vehicle, wherein the motor control system and the sensors are interfaced via isolators;

wherein the motor control system is configured to control a current of the motor to operate the motor to selectively provide positive or negative torque to the engine based on signals from sensors within the vehicle that are used to predict power demand of the engine, and

wherein the motor transmission system comprises either (a) a first pulley with a profiled groove coupled to a shaft of the motor, a second pulley coupled to a crank shaft of the engine, and a belt operably coupling the first pulley to the second pulley or (b) a universal coupling configured to couple a shaft of the motor directly to a crank shaft of the engine.

2. The modular power assisting system of claim 1, wherein the sensor system comprises isolator circuitry that includes galvanic isolated digital circuitry, isolated pulse width modulator and encoder circuitry, and galvanic isolated analog circuitry.

3. The modular power assisting system of claim 1, wherein the motor control system comprises a PID controller, a power device, a reservoir capacitor, a microcontroller, a data storage device, a memory, a power source, and a data input and output system.

4. The modular power assisting system of claim 3, wherein the data input and output system comprises:

a scalable analog input interface configured to receive signals from at least one of a temperature sensor, a throttle sensor, or a brake sensor;

a scalable pulse width modulated input interface configured to receive signals from a magnetic pickup for sensing at least one of engine speed or vehicle speed;

a digital output interface configured to operate relays to control at least one of a fuel supply, a cooling fan, or a pump;

a scalable analog output interface configured to drive at least one of a dashboard display and an actuator;

a scalable pulse width modulated output interface configured to drive the motor;

at least one of an encoder input interface or a tachometer input interface configured to receive position and direction feedback of the motor; and

a controller area network communication port configured to communicate with at least one of an engine control unit, a security device, or a display.

5. The modular power assisting system of claim 1, wherein a sensor associated with at least one of a brake, a handbrake, a clutch, an air conditioner, an ignition, or a mode selection circuit is interfaced with the motor control system using galvanic isolated digital circuitry.

6. The modular power assisting system of claim 1, wherein pulsating signals from a vehicle speed sensor, an engine speed sensor, and one or more encoders are interfaced with the motor control system using galvanic isolated pulse width modulator and encoder circuitry.

7. The modular power assisting system of claim 1, wherein signals related to a motor temperature, an engine temperature, a battery temperature, a throttle position, a manifold pressure, and a brake position are interfaced with the motor control system using galvanic isolated analog circuitry.

8. The modular power assisting system of claim 1, wherein the motor control system is configured to communicate with fuel injectors of the engine using a potential-free non-contact type relay digital output.

9. The modular power assisting system of claim 8, wherein the potential-free non-contact type relay digital output is configured to communicate with a DC power supply, a controller cooling fan, a fault lamp, and a pump.

10. The modular power assisting system of claim 1, wherein the motor control system is configured to start the vehicle, wherein the modular power assisting system is configured to:

sense that an accelerator paddle is in an accelerated position, wherein the accelerator paddle is interlocked with an ignition switch of the engine;

initiate an excitation current to the motor to start the motor, wherein an engine fuel supply is not initiated so that the vehicle operates with the motor as the only power source;

sense a vehicle speed using a vehicle speed sensor; and

when the vehicle speed exceeds a predetermined speed, initiate a signal to a solenoid valve of the engine fuel supply.

11. The modular power assisting system of claim 1, wherein the motor control system is configured to start the vehicle, wherein the modular power assisting system is configured to:

upon sensing that an accelerator paddle has been pressed, send a signal representing that acceleration has been sensed to the motor control system;

initiate an excitation current to the motor to start the motor;

initiate a fuel supply to the engine; and

operate the motor and the engine simultaneously to power the vehicle.

12. The modular power assisting system of claim 1, wherein the motor control system is configured to:

interface with existing sensors of the vehicle so as to acquire signals from the existing sensors;

measure a difference between an ambient pressure and an intake manifold pressure and communicate the difference to a data processing device;

measure a throttle position and communicate the throttle position to the data processing device;

estimate engine demand based on the measurement of the difference between the ambient pressure and the intake manifold pressure and the measurement of the throttle position;

estimate a motor power necessary to assist the engine; and

transmit a signal to the motor to respond to the engine demand.

13. The modular power assisting system of claim 1, wherein the system is configured such that at high vehicle speeds, the motor control system monitors the demand of the engine and instructs the motor to operate below its peak power to provide assistance to the engine in the event of a sudden acceleration demand to reduce the necessity of frequent gear shifts.

14. The modular power assisting system of claim 1, wherein the system is configured such that at low vehicle speeds, the motor control system monitors the demand of the engine with respect to dynamic speed change of the vehicle and instructs the motor to operate at its peak power before the engine can respond to the dynamic speed change.

15. The modular power assisting system of claim 1, wherein the system is configured to allow the vehicle to be operated using only the electric motor at low speeds.

16. The modular power assisting system of claim 1, wherein the sensor system is configured to receive signals from a torque positioning sensor, a manifold absolute pressure sensor, a vehicle speed sensor, a brake, a handbrake, a clutch, a reverse switch, an engine RPM sensor, a coolant temperature sensor, a mass air flow sensor, a battery temperature sensor, and an accelerator paddle position sensor.

17. The modular power assisting system of claim 1, wherein the mounting structure comprises a bracket including a first surface that is substantially flat and includes at least one opening for mounting the motor and a second surface that is substantially flat and is coupled to the first surface with ribs, wherein the second surface comprises at least one elongated opening.

18. The modular power assisting system of claim 17, wherein the mounting structure further comprises a vibration isolation structure on at least one of the first or second surfaces to provide isolation from the engine of the vehicle.

19. The modular power assisting system of claim 18, wherein the vibration isolation structure comprises a cylindrical, sandwich type mount.

20. The modular power assisting system of claim 1, wherein the motor transmission system comprises a first pulley with a profiled groove coupled to the shaft of the motor, a second pulley coupled to the crank shaft of the engine, and a belt operably coupling the first pulley to the second pulley.

21. The modular power assisting system of claim 20, wherein the belt comprises one of a V type belt, a chain belt, or a ribbed belt.

22. The modular power assisting system of claim 21, further comprising a belt tensioning pulley configured to maintain belt tension between the first and second pulleys.

23. The modular power assisting system of claim 1, wherein the motor transmission system comprises a universal coupling or jaw coupling that couples the shaft of the motor directly to a crank shaft of the engine.

24. The modular power assisting system of claim 1, wherein the energy storage system further comprises a dedicated battery control system embedded with a battery control program logic loop.

25. The modular power assisting system of claim 1, wherein the energy storage device further comprises an ultra capacitor.

26. The modular power assisting system of claim 25, wherein the energy storage device is configured such that the ultra capacitor provides power to the motor during certain conditions and the at least one battery provides power to the motor during certain other conditions.

27. The modular power assisting system of claim 1, wherein the at least one battery is a lead acid battery, a lithium-ion battery, or a nickel-metal-hydride battery.

28. The modular power assisting system of claim 1, wherein the regenerative braking system is configured to capture energy using super capacitors and to charge the at least one battery of the energy storage system.

29. The modular power assisting system of claim 1, wherein the motor control system is configured to start the vehicle, and wherein the modular power assisting system is configured to:

sense whether the ignition is on and detect whether any faults are present;

sense vehicle speed using a vehicle speed sensor;

if the vehicle is at a standstill, sense a throttle position using a throttle position sensor and a clutch sensor and, if the throttle position sensor indicates greater than a preset accelerator position and the clutch sensor indicates a pressed condition, start the engine by applying a 100% torque set point to the motor and initiating a power assist process in which the motor provides a power assist to the engine; and

if the vehicle is moving, sense whether the throttle position is greater than 0%, and if so, initiate a power assist process in which the motor provides a power assist to the engine.

30. The modular power assisting system of claim 1, wherein the motor control system operates to cut off fuel supply of the engine, and wherein the modular power assisting system is configured to:

sense ignition state and sense faults;

sense whether vehicle speed is zero using a vehicle speed sensor;

sense whether a state of charge of the at least one battery and an engine temperature are above preset levels;

begin delay;

sense the vehicle speed;

set injector relays to cut-off the fuel supply to the engine; and

if the vehicle speed is not zero, sense a throttle position using a throttle position sensor, wherein, if the throttle position is greater than zero, a power assist process is initiated, and wherein, if the throttle position is not greater than zero, a regeneration process is initiated.

31. The modular power assisting system of claim 1, wherein the motor control system operates to initiate a power assisting mode to the engine, and wherein the modular power assisting system is configured to:

sense whether a state of charge position is greater than or less than zero;

based on the state of charge position, selecting a city running mode or a parallel hybrid mode;

if the city running mode is selected, determine the vehicle speed using a vehicle speed sensor with respect to a minimum vehicle speed below which the vehicle will run in an electric mode and benchmark the vehicle speed against a pre-set speed, and

if the vehicle speed is greater than the pre-set speed, reset fuel injector relays to enable the engine to start and run the vehicle in the parallel hybrid mode wherein engine power as well as motor power assist is utilized, and

if the vehicle speed is below the pre-set speed, set the fuel injector relays to cut off an engine fuel supply and operate the motor to drive the engine at an idle rpm by adding an offset to a control system set point, and recheck the vehicle speed; and

if parallel hybrid mode is selected, reset the fuel injector relay to enable the engine to start so as to run the vehicle in the parallel hybrid mode.

32. The modular power assisting system of claim 1, wherein the motor control system operates so as to operate the vehicle in parallel hybrid condition, and wherein the modular power assisting system is configured to:

identify a gear position based on the gear ratios of the engine system;

select an appropriate torque requirement based on the gear position, vehicle speed, and engine speed;

sense a throttle position using a throttle position sensor and determine torque requirement;

if the torque requirement is greater than a no-load requirement, establish a torque set point that is proportional to a throttle percentage opening, and if the torque requirement is zero, operating in a regeneration mode;

monitoring a motor winding temperature; and

if the motor winding temperature is greater than a preset temperature, reducing a motor current by fractional amounts for every degree rise in motor winding temperature.

33. The modular power assisting system of claim 1, wherein the regenerative braking system is configured to perform a method comprising the steps of:

sensing whether the vehicle brakes are being applied;

if the brakes are being applied, setting a regeneration current limit to a first value to apply electric brakes;

if the brakes are not being applied, setting the regeneration current limit to a second value lower than the first value;

measuring a temperature of the at least one battery;

if the battery temperature is greater than a preset operating temperature, reducing the regeneration current limit to a nominal charging current rating of the battery.

34. The modular power assisting system of claim 1, wherein the system is configured for use with at least one of a two wheel, three wheel, or four wheel vehicle.

35. The modular power assisting system of claim 1, wherein a ratio of a diameter of the first pulley to a diameter of the second pulley is in a range from 1:

1 to 1;

2.

36. The modular power assisting system of claim 1, wherein an engine drive system on which the modular power assisting system is adapted operates at reduced power than the rated power of the engine drive system.

37. The modular power assisting system of claim 1, further comprising a security device communicably linked with the motor control system and configured to transmit signals to the motor control system based on an operating mode of the vehicle, wherein the security device is configured to:

during a starting mode of the vehicle, after a key is placed in an ignition of the vehicle, transmit one or more signals required for starting the vehicle to the motor control system,

during a running mode of the vehicle, transmit one or more signals required for the running mode to the motor control system, wherein one or more commands received during the starting mode are erased from a memory of the motor control system, and

during a ceasing operation mode of the vehicle, when the vehicle is shut off, commands received from the security device are erased from the memory of the motor control system.

38. A modular power assisting system for a vehicle comprising:

a security device communicably linked with a motor control system, wherein the motor control system is configured to provide at least one of speed control or torque control for a motor system that is configured to assist an engine of the vehicle, wherein the security device is configured to transmit signals to the motor control system based on an operating mode of the vehicle, and wherein the security device is configured to;

during a starting mode of the vehicle, after a key is placed in an ignition of the vehicle, transmit one or more signals required for starting the vehicle to the motor control system,

during a running mode of the vehicle, transmit one or more signals required for the running mode to the motor control system, wherein one or more commands received during the starting mode are erased from a memory of the motor control system, and

during a ceasing operation mode of the vehicle, when the vehicle is shut off, commands received from the security device are erased from the memory of the motor control system.

39. A modular power assisting system for a vehicle comprising:

a motor control system comprising a PID controller, a power device, a reservoir capacitor, a microcontroller, a data storage device, a memory, a power source, and a data input and output system, wherein the data input and output system comprises;

a scalable analog input interface configured to receive signals from at least one of a temperature sensor, a throttle sensor, or a brake sensor;

a scalable pulse width modulated input interface configured to receive signals from a magnetic pickup for sensing at least one of engine speed or vehicle speed;

a digital output interface configured to operate relays to control at least one of a fuel supply, a cooling fan, or a pump;

a scalable analog output interface configured to drive at least one of a dashboard display and an actuator;

a scalable pulse width modulated output interface configured to drive the motor;

at least one of an encoder input interface or a tachometer input interface configured to receive position and direction feedback of the motor; and

a controller area network communication port configured to communicate with at least one of an engine control unit, a security device, or a display,

wherein digital signals from sensors are interfaced with the motor control system using galvanic isolated digital circuitry, pulsating signals from the sensors are interfaced with the motor control system using galvanic isolated pulse width modulation and encoder circuitry, and analog signals from sensors are interfaced with the motor control system using galvanic isolated analog circuitry, and

wherein, upon adaptation onto an engine drive system of the vehicle, the motor control system is configured to;

interface with existing sensors of the vehicle so as to acquire signals from the existing sensors,

measure a difference between an ambient pressure and an intake manifold pressure and communicate the difference to a data processing device,

measure a throttle position and communicate the throttle position to the data processing device, and

estimate engine demand based on the measurement of the difference between the ambient pressure and the intake manifold pressure and the measurement of the throttle position.

40. The modular power assisting system of claim 39, wherein the motor control system is further configure to measure airflow to the engine.