Electric vehicle monitoring system

• US 5,534,759 A
• Filed: 05/19/1995
• Issued: 07/09/1996
• Est. Priority Date: 05/19/1995
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: White, Robert J., Brown, Russell L., Galliher, Kenneth R., Evans, Le Andra E., Carlson, Mark E.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Masih, Karen
• Application Number:
  US08/445,152
• Time in Patent Office: 417 Days
• Field of Search: 318/139, 318/641, 318/648, 318/490, 180/65.1, 180/53.5, 320/48, 364/424.05, 364/551.01
• US Class Current: 318/139
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An Electric Vehicle Monitoring System (EVMS) for measuring the performancef an electric vehicle. The preferred embodiment of the system comprises: (1) a variety of sensors for obtaining data on vehicle performance and operating parameters; (2) a digital dashboard display providing the vehicle operator with information on vehicle operating parameters; (3) a data acquisition system for collecting the data from the sensors and converting the data to digital format; and (4) a processing unit in the form of a removable, portable or notebook computer used for storing, evaluating and providing reports of the digital format data. The EVMS is adapted for use in a vehicle specifically designed for electric propulsion or for use in an internal combustion engine vehicle converted to electrical power use. The sensors include voltmeters, ammeters, thermocouples, optical shaft encoders and an inclinometer and provide data to both the operator display and the data acquisition system. The operator display includes bargraphs for current draw, motor and battery temperature, accessory battery voltage, main battery voltage or "fuel level" and alphanumeric displays for vehicle speed, distance traveled, trip meter and transmission gear indicator.

Claims

1. In an electric powered vehicle having a main electric power source transmitting power to an electric motor and having an accessory electric power source, a system for monitoring performance of said electric powered vehicle comprising:

sensor means for measuring performance characteristics of said electric powered vehicle and producing data signals corresponding to said measured performance characteristics, said sensor means comprising a first voltmeter for measuring a main voltage across said main electrical power source, a second voltmeter for measuring an accessory voltage across said accessory electric power source, a first ammeter for measuring an operating current draw of said main electrical power source when said electric powered vehicle is in an operating mode, a second ammeter for measuring a second current draw of said main electric power source when said electric powered vehicle is in an operating mode and when said electric powered vehicle is in a charging mode, a plurality of thermocouples for measuring a plurality of temperatures interior and exterior to said electric powered vehicle, a plurality of optical shaft encoders for measuring a plurality of shaft rotation rates within said electric powered vehicle and an inclinometer for measuring an angle of an incline on which said vehicle is travelling;

a data acquisition means electrically connected to said sensor means for collecting said data signals from said sensor means and converting said data signals from said sensor means into digital input signals;

a processing unit electrically connected to said data acquisition means for receiving said digital input signals from said data acquisition means, said processing unit storing and interpreting said digital input signals, said processing unit further generating reports of said performance characteristics; and

an operator display electrically connected to said sensor means for displaying operating characteristics of said electric powered vehicle, said operating characteristics corresponding to at least one of said performance characteristics, said operator display located within said electric powered vehicle to be in view of an operator of said vehicle when said operator is driving said vehicle.

2. A system according to claim 1 wherein said first voltmeter is a differential voltmeter, said first voltmeter being further isolated from an electrical grounding system of said electric powered vehicle, said ground isolation allowing said first voltmeter to measure main voltage without discharging said main electric power source.

3. A system according to claim 1 wherein said first ammeter is a shunt ammeter and said second ammeter is an inductive ammeter.

4. A system according to claim 1 wherein said plurality of thermocouples further comprises:

a first thermocouple for measuring a case temperature of said main electric power source;

a second thermocouple for measuring an electrolyte temperature of said main electric power source, said second thermocouple being resistant to acid;

a third thermocouple for measuring a temperature exterior to said electric powered vehicle; and

a fourth thermocouple for measuring a temperature of said electric motor.

5. A system according to claim 1 wherein said plurality of optical shaft encoders further comprises:

a first shaft encoder for providing measurements corresponding to a speed of said electric powered vehicle;

a second shaft encoder for providing measurements corresponding to a distance travelled by said electric powered vehicle; and

a third shaft encoder for providing measurements corresponding to a rotation of said electric motor.

6. A system according to claim 1 wherein:

said processing unit is a portable computer having a processing power source separate from said main electric power source and separate from said accessory electric power source;

said portable computer further comprises a memory for storing additional data input into said memory by an operator of said electric powered vehicle;

said processing unit senses the position of an ignition switch of said electric powered vehicle;

said processing unit enters a standby mode when said ignition switch is in an off position, said standby mode conserving said processing power source; and

said processing unit enters an active mode when said ignition switch is in an on position, said active mode storing and interpreting said digital input signals from said data acquisition means.

7. A system according to claim 1 wherein said operating characteristics further comprise:

said operating current draw;

said second current draw;

a temperature of said electric motor as measured by said plurality of thermocouples;

a temperature of said main electric power source as measured by said plurality of thermocouples;

said main voltage; and

said accessory voltage.

8. A system according to claim 7 wherein said operator display further comprises:

an alphanumeric indication of a gear engaged by said electric motor;

a numeric indication of a speed of said electric powered vehicle; and

a numeric indication of a distance traveled by said electric powered vehicle.

9. A system according to claim 7 wherein said operating characteristics are represented in the form of bargraphs, each one of said operating characteristics being represented by a separate bargraph.

10. A system according to claim 9 wherein a bargraph representing said operating current draw has a plurality of distinct colors, said distinct colors indicating efficient operating ranges for said electric motor.

11. A system according to claim 10 wherein a bargraph representing said main voltage indicates a fuel level, said fuel level corresponding to a level of power remaining in said main electric power source.

12. In a vehicle converted from an internal combustion engine power source to an electrical power source, a system for measuring performance characteristics of said vehicle and displaying operating characteristics of said vehicle corresponding to said performance characteristics to an operator of said vehicle, said system comprising:

sensor means for measuring said performance characteristics of said vehicle and producing data signals corresponding to said measured performance characteristics, said sensor means comprising voltmeter means for measuring a voltage of said electrical power source, ammeter means for measuring a current draw from said electrical power source, temperature sensor means for measuring temperatures of said electrical power source and of an electric motor powered by said electrical power source and causing the movement of said vehicle, shaft encoder means for measuring shaft rotations corresponding to a speed of said vehicle and to a distance travelled by said vehicle, and an inclinometer means for measuring an angle of an incline on which said vehicle is travelling;

a data acquisition means electrically connected to said sensor means for collecting said data signals from said sensor means, said data acquisition means converting said data signals to digital signals;

a portable computer unit electrically connected to said data acquisition means and having a computer power source separate from said electrical power source of said vehicle for receiving said digital signals from said data acquisition means, said portable computer unit receiving operator input signals from said operator of said vehicle, said portable computer unit storing and interpreting said digital signals and said operator input signals, said portable computer unit further generating reports of said digital signals and said operator input signals, said reports corresponding to performance characteristics of said vehicle; and

an operator display electrically connected to said sensor means for displaying operating characteristics of said electric powered vehicle, said operating characteristics corresponding to at least one of said performance characteristics, said operator display replacing a dashboard display of said vehicle, said dashboard display corresponding to internal combustion operating characteristics of said vehicle operating with said internal combustion engine power source, said operator display comprising a fuel level bargraph display corresponding to said voltage, an operating range bargraph display corresponding to said current draw and color coded to indicate an efficient operating range of said electric motor, a temperature bargraph display corresponding to said measured temperatures, a first digital display corresponding to said speed and a second digital display corresponding to said distance.

13. A system according to claim 12 wherein said portable computer unit senses the position of an ignition switch of said electric powered vehicle, said portable computer unit entering a standby mode when said ignition switch is in an off position, said standby mode conserving said computer power source.