Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to a charging system of an electric tractor and more particularly, to a charging system on top of a rollover protection structure (ROPS) of the electric tractor.

BACKGROUND
[002] In an electric tractor, there is a need for electricity to be harnessed externally from an external power source to charge a battery of the electric tractor. Typically charging device along with a cable is used to charge the battery from the external power source. A user has to manually connect the electric tractor to the power source via the charging device. The operation of pulling out and plugging in the charging device from the power source to charge the electric tractor is complicated and impose safety hazard to human operator. Further, there is no isolation between the charging interface and the external environment.
[003] In addition, usage of tethered charger for charging the electric tractor is not flexible and limits the distance as the cable is integrated to the charger. Hence, cable cannot be changed based on the need. The entire tethered charger unit needs to be changed if the length of the cable integrated to the charger is less than the required length. Further, sliding electrodes are used to make an electrical contact with the external power source. However, the sliding electrodes are hazardous while being powered as it is exposed with lesser protection.
[004] Furthermore, electric vehicle charging using overhead electric line requires long pantograph arrangement on the roof of the electric tractor. Such pantograph arrangement on the roof of the electric tractor increases weight and aerodynamic drag.
OBJECTS
[005] The principal object of the embodiments herein is to provide a telescopic mechanism attached to a top of a rollover protection structure (ROPS) to receive electric power from overhead electric line to charge a battery of an electric tractor.
[006] Another object of the embodiments herein is to prevent electrocution by providing the telescopic mechanism including pair of electrodes for charging the electric tractor on top of the ROPS by isolating the charging interface from the inside of the electric tractor.
[007] Another object of the embodiments herein is to provide the telescopic mechanism to continuously access an external power source when an electric tractor is in motion or parked.
[008] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[009] The embodiments disclosed herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0010] Fig. 1A illustrates a side view of an electric tractor having a telescopic mechanism in an extended position, where the telescopic mechanism is attached to a top of a rollover protection structure (ROPS), according to embodiments as disclosed herein;
[0011] Fig. 1B illustrates a side view of the electric tractor having the telescopic mechanism in a retracted position, where the telescopic mechanism is attached to the top of the ROPS, according to embodiments as disclosed herein;
[0012] Fig. 2 depicts a schematic flow diagram of a procedure to charge the battery of the electric tractor using the electric power received from the overhead electric line, according to embodiments as disclosed herein;
[0013] Fig. 3 depicts a schematic flow diagram of a procedure to operate the traction motor by using the electric power received from the overhead electric line, according to embodiments as disclosed herein;
[0014] Fig. 4 illustrates a flowchart indicating steps of a method for charging the battery of the electric tractor using a telescopic mechanism attached to the top of the ROPS, according to embodiments as disclosed herein.
DETAILED DESCRIPTION
[0015] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0016] The embodiments herein disclose a charging system attached to a top of a rollover protection structure (ROPS) of an electric tractor for charging a battery of the electric tractor based on a state of charge (SoC) of the battery of the electric tractor. Referring now to figs. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown at least one embodiment.
[0017] Figs. 1A through 4 depict a charging system (110) for charging the battery (B) of the electric tractor (100). The charging system (110) includes the battery (B), a controller (120), a telescopic mechanism (104) attached to the top of the ROPS (106), a pneumatic actuator (not shown), and a user interface (not shown), according to embodiments as disclosed herein.
[0018] In an embodiment herein, the telescopic mechanism (104) is configured to hold a pair of electrodes (102). The pneumatic actuator is coupled to the telescopic mechanism (104). The controller (200) is configured to receive state of charge (SoC) information of the battery (B) of the electric tractor (100) and transmit control signals based on the received SoC information to the pneumatic actuator to control pneumatic pressure applied to the telescopic mechanism (104). The controller (120) is connected to the pneumatic actuator via electric wires and the controller (120) is configured to transmit the control signals via the electric wires to the pneumatic actuator. The pneumatic pressure applied to the telescopic mechanism (104) is increased based on the control signals when the received information indicates that the SoC of the battery (B) is less than a predetermined threshold and the telescopic mechanism operates in an extended position.
[0019] In the extended position, the pair of electrodes (102) in the telescopic mechanism (104) contacts the overhead electric line (L) as shown in Fig. 1A and an electric power is received from the overhead electric line (L). The controller (120) as shown in Fig. 2 includes AC input filter (122), AC-DC rectifier (124), and DC-DC converter (126). The received electric power is filtered by the AC input filter (122). The electric power filtered by the AC input filter (122) is provided as an input to the AC-DC rectifier (124). The AC-DC rectifier (124) is configured to convert the filtered AC electric power to the DC electric power. The converted DC electric power is provided as an input to the DC-DC converter (126). The DC-DC converter (126) is configured to convert the DC electric power to a prespecified DC electric power. The prespecified DC electric power is provided as an input to the battery (B) to charge the battery (B). The battery (B) is charged until the SoC of the battery (B) is equal to a predetermined threshold. The controller (120) is configured to transmit control signals to the pneumatic actuator to reduce the pneumatic pressure applied to the telescopic mechanism (104) to retract the telescopic mechanism (104) based on the received information that indicates that the SoC of the battery (B) is equal to or greater than the predetermined threshold.
[0020] In an embodiment herein, a tilt sensor is mounted on the electric tractor (100). The tilt sensor is configured to detect a tilt angle of the electric tractor (100) with respect to a horizontal surface. The detected tilt angle is transmitted to the controller (120). The controller (120) is configured to compare the detected tilt angle to a threshold angle to determine an occurrence of rollover of the electric tractor (100). Further, the controller (120) is configured to retract the telescopic mechanism (104) based on a result of the comparison that indicates that the detected tilt angle is equal to or greater than the threshold angle. The threshold angle is 20° with respect to the horizontal surface.
[0021] According to embodiments disclosed herein, the electric tractor (100) includes a user interface connected to the controller. A user can provide a start signal to start an operation of the electric tractor or a stop signal to stop the operation of the electric tractor via the user interface.
[0022] When a user provides a start signal as an input in the user interface, the input received from the user interface is transmitted to the controller (120). The controller (120) is configured to transmit control signals to increase the pneumatic pressure applied to the pneumatic actuator attached to the telescopic mechanism (104) on receiving the start signal from the user interface. The pneumatic actuator is configured to receive the control signals from the controller (120) and the pneumatic pressure applied to the telescopic mechanism (104) is increased to operate the telescopic mechanism (104) in the extended position. As the telescopic mechanism (104) operates in the extended position, the pair of electrodes (102) in the telescopic mechanism (104) contacts the overhead electric line (L) and the AC electric power is received from the overhead electric line (L). As shown in Fig. 3, the received AC power is filtered by the AC input filter (122). The filtered AC power is transmitted to the AC-DC rectifier (124) to convert the filtered AC power to DC power. The converted DC power is provided as an input to the DC-AC inverter (128) to convert the DC power to AC power. The AC power is provided as an input to the traction motor (M) to propel the electric tractor (100).
[0023] In an embodiment herein, the user provides the stop signal as the input in the user interface. The stop signal received in the user interface is transmitted to the controller (120). The controller (120) is configured to transmit control signals to reduce the pneumatic pressure applied to the pneumatic actuator attached to the telescopic mechanism (104) on receiving the stop signal. The pneumatic actuator is configured to receive the control signals from the controller (120) and reduce the pneumatic pressure applied to the telescopic mechanism to operate the telescopic mechanism (104) in the retracted position in order to stop the operation of the electric tractor (100).
[0024] Fig. 4 illustrates a flowchart indicating steps of a method (400) for charging a battery (B) of an electric tractor (100) based on state of charge (SoC) information of the battery (B), according to embodiments as disclosed herein. At step (402), the method (400) includes providing a telescopic mechanism (104) attached to a top of the ROPS (106) of the electric tractor (100). At step 404, the method (400) includes receiving the SoC information of the battery (B) of the electric tractor (100) by controller (120). Further, the method (400) at step (406) includes comparing the SoC of the battery (B) with a predetermined threshold. The method (400) at step (408) and step (410) includes controlling the telescopic mechanism (104) between an extended position and a retracted position based on a result of the comparison.
[0025] The method step (408) includes controlling the telescopic mechanism (104) to the extended position from the retracted position based on the received information that indicates that the SoC of the battery (B) is less than the predetermined threshold. The step (408) of controlling the telescopic mechanism (104) to the extended position includes transmitting control signals by the controller (120) to increase a pneumatic pressure applied by a pneumatic actuator to the telescopic mechanism (104). The pressure applied to the telescopic mechanism (104) is increased so as to operate the telescopic mechanism (104) in the extended position. The pair of electrodes (102) in the telescopic mechanism (104) contacts the overhead electric line (L) when the telescopic mechanism (104) is in the extended position. The AC electric power is received from the said overhead electric line (L) via the pair of electrodes (102). Furthermore, the method at step (408) includes converting the received AC electric power into a DC electric power by the AC-DC rectifier (124) of the controller (120). The DC electric power is provided as an input to a DC-DC converter (126). The DC-DC converter (126) converts the input DC voltage to a prespecified DC voltage. The prespecified DC voltage is provided to the battery (B) for charging the battery (B) until the SoC of the battery (B) is equal to the predetermined threshold.
[0026] In an embodiment herein, the method step (410) further includes transmitting control signals from the controller (120) to the pneumatic actuator to reduce the pneumatic pressure applied to the telescopic mechanism to operate the telescopic mechanism (104) in the retracted position when the SoC of the battery (B) is equal to or greater than the predetermined threshold.
[0027] According to embodiments disclosed herein, the method (400) includes receiving a tilt angle with respect to a horizontal surface from a tilt sensor and comparing the received tilt angle to a threshold angle. When the received tilt angle is equal to or greater than the threshold angle, the method (400) includes transmitting control signals to the pneumatic actuator to reduce the pneumatic pressure applied to the telescopic mechanism (104) for operating the telescopic mechanism (104) in the retracted position. The threshold angle is 20° with respect to the horizontal surface. Hence, the ROPS (106) protects the user during the occurrence of roll-over. Further, the pair of electrodes (102) are protected during roll-over.
[0028] In an embodiment herein, the method (400) includes receiving a start signal from a user and transmitting the control signals from the controller to the pneumatic actuator to increase the pneumatic pressure applied to the telescopic mechanism (104) to operate the telescopic mechanism (104) in the extended position. In the extended position, the pair of electrodes (102) of the telescopic mechanism (104) contacts the overhead electric line (L). Further, the method (400) includes, receiving the electric power from the overhead electric line (L), filtering the received electric power by the AC input filter (122) of the controller (120), converting the filtered AC input power to DC electric power by the AC-DC rectifier (124), converting the DC electric power to AC electric power by DC-AC inverter (128), and supplying the AC electric power to the traction motor (M) to operate the electric tractor (100).
[0029] The proposed charging system is easy to install. The telescopic mechanism having a pair of electrodes is attached to the top of ROPS, in which the ROPS has a taller reach to overhead electric line above the vehicle, so the charging system has easy access to an external electric power source. The telescopic mechanism in the charging system has continuous access to the external power source when the electric tractor is in motion or parked. The charging system requires fewer parts and lesser weight as compared to the existing charging systems. Further, the charging system infrastructure is compatible to existing electric infrastructure. The charging safety is improved as the charging interface is isolated from the inside of the vehicle.
[0030] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the elements. The elements can be at least one of a hardware device, or a combination of hardware device and software module.
[0031] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of at least one embodiment, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
, Claims:We claim:
1. A charging system (110) for an electric tractor (100), said electric tractor (100) having a rollover protection structure (ROPS) (106), said charging system (110) comprising:
a battery (B);
a controller (120); and
a telescopic mechanism (104), said telescopic mechanism (104) attached to a top of said ROPS (106) of said electric tractor (100), said telescopic mechanism (104) is configured to hold a pair of electrodes (102), wherein said controller (120) configured to receive state of charge (SoC) information of said battery (B) and control said telescopic mechanism (104) between an extended position and a retracted position based on said received SoC information.

2. The charging system (110) as claimed in claim 1, wherein said telescopic mechanism (104) is attached to an actuator, wherein
said actuator is a pneumatic actuator,
said actuator is configured to receive control signals from said controller (120) via electric wires, and
said controller (120) is configured to cause said pneumatic actuator to increase a pneumatic pressure applied to said telescopic mechanism (104) to operate said telescopic mechanism (104) in said extended position and cause said pneumatic actuator to decrease said pneumatic pressure applied to said telescopic mechanism (104) to operate said telescopic mechanism (104) in said retracted position based on said control signals.

3. The charging system (110) as claimed in claim 1, wherein
said controller (120) is configured to operate said telescopic mechanism (104) in said extended position if said SoC information of said battery (B) is less than a predetermined threshold, wherein
said pair of electrodes (102) contacts an overhead electric line (L) when said telescopic mechanism (104) is in said extended position, and
an AC electric power is received from said overhead electric line (L) via said pair of electrodes (102);
said controller (120) includes an AC-DC rectifier (124) configured to convert said received AC electric power into a DC power; and
charge said battery (B) until said SoC of said battery (B) is equal to said predetermined threshold using said converted DC power.

4.The charging system (110) as claimed in claim 3, wherein said controller (120) is configured to operate said telescopic mechanism (104) in said retracted position if said SoC of said battery (B) is equal to or greater than said predetermined threshold.

5.The charging system as claimed in claim 1, wherein said controller (120) is configured to:
receive a tilt signal including information that indicates tilt angle with respect to a horizontal surface from a tilt sensor attached to said electric tractor (100), wherein said tilt sensor is configured to detect a tilt of said electric tractor with respect to a horizontal surface;
compare said received tilt angle with a predetermined threshold angle; and
retract the telescopic mechanism (104) based on a result of comparison that indicates that said received tilt angle is greater than said predetermined threshold angle, wherein said predetermined threshold angle is 20° with respect to the horizontal surface.

6. The charging system as claimed in claim 1, wherein said controller (120) is configured to:
operate said telescopic mechanism (104) in said extended position by receiving a start signal from a user, wherein said pair of electrodes (102) contacts the overhead electric line (L) to receive an electric power when said telescopic mechanism (104) is in said extended position;
transmit said received electric power to a traction motor (M) of said electric tractor (100) to start an operation of said electric tractor (100); and
operate said telescopic mechanism (104) to said retracted position by receiving a stop signal from the user to stop said operation of said electric tractor (100).

7. A method (400) of charging an electric tractor (100), said electric tractor (100) having a rollover protection structure (ROPS) (106), said method (400) comprising:
providing a charging system (110) in said electric tractor (100), wherein said charging system (110) includes a battery (B), a controller (120), a telescopic mechanism (104) attached to a top of said ROPS (106) of said electric tractor (100), and an actuator coupled to said telescopic mechanism (104), wherein said telescopic mechanism (104) is configured to hold a pair of electrodes (102); and
receiving, by said controller (120), state of charge (SoC) information of said battery (B) of said electric tractor (100); and
controlling, by said controller (120), said telescopic mechanism (106) between an extended position and a retracted position based on said received SoC information.

8. The method (400) as claimed in claim 7, wherein said method (400) comprising:
transmitting control signals via electric wires, by said controller (120) to said pneumatic actuator, to increase a pneumatic pressure applied to said telescopic mechanism (104) to operate said telescopic mechanism (104) in said extended position if said SoC of said battery (B) is less than a predetermined threshold, wherein said pair of electrodes (102) contacts said overhead electric line (L) to receive an electric power;
converting said power into a DC power; and
charging said battery (B) until said SoC of said battery (B) is equal to said predetermined threshold.
9. The method (400) as claimed in claim 8, wherein said method (400) comprising operating said telescopic mechanism (104) in said retracted position if said SoC of said battery (B) is equal to or greater than said predetermined threshold.

10. The method (400) as claimed in claim 8, wherein said method (400) comprising:
receiving a tilt signal including information that indicates tilt angle with respect to a horizontal surface from a tilt sensor attached to said electric tractor (100), wherein said tilt sensor is configured to detect a tilt of said electric tractor (100) with respect to a horizontal surface;
comparing said received tilt angle with a predetermined threshold angle; and
retracting the telescopic mechanism (104) based on a result of comparison that indicates that said received tilt angle is greater than said predetermined threshold angle, wherein said predetermined threshold angle is 20° with respect to said horizontal surface.

11. The method (400) as claimed in claim 8, wherein said method (400) comprising:
operating said telescopic mechanism (104) in said extended position by receiving a start signal from a user, wherein said pair of electrodes (102) contacts the overhead electric line (L) to receive said electric power when said telescopic mechanism (104) is in said extended position;
transmitting said received electric power to a traction motor (M) of said electric tractor (100) to start an operation of said electric tractor (100); and
operating said telescopic mechanism (104) in said retracted position by receiving a stop signal from the user to stop said operation of said electric tractor (100).