title: Prismatic axis, differential-drive robotic kiwifruit harvester for reduced cycle time

authors: Barnett, Josh

subjects: robotics

abstract: The New Zealand kiwifruit industry is currently worth over NZD 2 billion in annual sales revenue, this is forecast to double within the next 5-10 years due to a significant increase in production volume. The industry is already experiencing a prevalent shortage of labour which is indicative of a global trend. The objective for this study was to define important metrics for the robotic harvesting of kiwifruit and to propose a hardware configuration which could improve on the current kiwifruit harvesting module (KHM) developed by the Multipurpose Orchard Robotics (MOR) project. The research scope was focused to establishing whether a prismatic axis kinematic structure was more effective than a rotational axis kinematic structure for the multiple-robot harvesting of kiwifruit. KPI's (key performance indicators) were defined as evaluation and design measures - these included fruit damage, harvestability and nominal harvest cycle time. An equation specific to the KHM was derived for the latter which included measures of fruit per harvesting phase, time between fruit and a proposed work distribution constant W_D. A prismatic axis, linear rail constrained, kiwifruit harvesting robot (LHR) with two robot-arms was developed, built and tested. It was found to be exponentially beneficial to locate mass proximal to the X axis carriage centres which is achieved with a differential-drive of the YZ axis'. The prismatic axis kinematic structure of the LHR allowed for an 88% greater work distribution constant W_D, a 40% greater harvestable taskspace volume V_h and 2.5 times greater overall workspace efficiency when compared to the KHM. The nominal harvest cycle time was identical for both of these systems. However, the LHR and the developed `x-rank' registry algorithm were capable of maintaining W_D value despite a two-fold increase in robot-arm density. Therefore, in non-collision scenarios the LHR can operate with four robot-arms without compromising performance. In this scenario where both systems have four robot-arms, the LHR had a 44% reduction in harvest cycle time. Further study would need to be done into manipulability measures, scheduling methods and the effects on work distribution to establish whether a prismatic axis structure remains favourable if an orientation structure is implemented for end-effector dexterity.

text: Prismatic axis, differential-drive robotic kiwifruit harvester for reduced cycle time The New Zealand kiwifruit industry is currently worth over NZD 2 billion in annual sales revenue, this is forecast to double within the next 5-10 years due to a significant increase in production volume. The industry is already experiencing a prevalent shortage of labour which is indicative of a global trend. The objective for this study was to define important metrics for the robotic harvesting of kiwifruit and to propose a hardware configuration which could improve on the current kiwifruit harvesting module (KHM) developed by the Multipurpose Orchard Robotics (MOR) project. The research scope was focused to establishing whether a prismatic axis kinematic structure was more effective than a rotational axis kinematic structure for the multiple-robot harvesting of kiwifruit. KPI's (key performance indicators) were defined as evaluation and design measures - these included fruit damage, harvestability and nominal harvest cycle time. An equation specific to the KHM was derived for the latter which included measures of fruit per harvesting phase, time between fruit and a proposed work distribution constant W_D. A prismatic axis, linear rail constrained, kiwifruit harvesting robot (LHR) with two robot-arms was developed, built and tested. It was found to be exponentially beneficial to locate mass proximal to the X axis carriage centres which is achieved with a differential-drive of the YZ axis'. The prismatic axis kinematic structure of the LHR allowed for an 88% greater work distribution constant W_D, a 40% greater harvestable taskspace volume V_h and 2.5 times greater overall workspace efficiency when compared to the KHM. The nominal harvest cycle time was identical for both of these systems. However, the LHR and the developed `x-rank' registry algorithm were capable of maintaining W_D value despite a two-fold increase in robot-arm density. Therefore, in non-collision scenarios the LHR can operate with four robot-arms without compromising performance. In this scenario where both systems have four robot-arms, the LHR had a 44% reduction in harvest cycle time. Further study would need to be done into manipulability measures, scheduling methods and the effects on work distribution to establish whether a prismatic axis structure remains favourable if an orientation structure is implemented for end-effector dexterity.

year: 2018

title: Exploration of Pervasive Games in Relation to Mobile Technologies

authors: Morris, Paul

abstract: The project is an exploration of Pervasive Games in relation to mobile technologies, with the intention of developing a pervasive game engine. Pervasive Games are interactive games where the participants drive the game play by playing the game in both the real world and a virtual environment. This is an area of gaming that has rapidly evolved over the last few years. 

The initial research involved establishing several key elements common to existing pervasive applications, defining real world / virtual world considerations for game play (both positive and negative) and identifying the technical requirements needed to implement play elements on a mobile device. After comparing several platforms the Windows 7 platform was selected for development purposes. The requirements for establishing a working development platform (with delivery mechanism) was investigated and a working environment set-up. 

A pervasive games engine was then developed in the format of 67 code stubs (coding solutions) that allow the implementation of solutions to gaming elements required in the development of pervasive applications. 

Two new helper classes were in addition developed containing solutions to topics related to run-time data storage (StorageUtils.cs) and generic gaming tasks (GameCode.cs). A pervasive game was implemented to test a cross section of functionality in the engine. The basic principle behind the game was to overlay various layers video, backgrounds, sprite and text, to build up an immersive pervasive environment with a player in the centre of the game imagery, game domain and real world. The intention of the game was to see how the pervasive game experience could be reflected in the game mechanics and pervasive interaction, while utilising the engine functionality.

text: Exploration of Pervasive Games in Relation to Mobile Technologies The project is an exploration of Pervasive Games in relation to mobile technologies, with the intention of developing a pervasive game engine. Pervasive Games are interactive games where the participants drive the game play by playing the game in both the real world and a virtual environment. This is an area of gaming that has rapidly evolved over the last few years. 

The initial research involved establishing several key elements common to existing pervasive applications, defining real world / virtual world considerations for game play (both positive and negative) and identifying the technical requirements needed to implement play elements on a mobile device. After comparing several platforms the Windows 7 platform was selected for development purposes. The requirements for establishing a working development platform (with delivery mechanism) was investigated and a working environment set-up. 

A pervasive games engine was then developed in the format of 67 code stubs (coding solutions) that allow the implementation of solutions to gaming elements required in the development of pervasive applications. 

Two new helper classes were in addition developed containing solutions to topics related to run-time data storage (StorageUtils.cs) and generic gaming tasks (GameCode.cs). A pervasive game was implemented to test a cross section of functionality in the engine. The basic principle behind the game was to overlay various layers video, backgrounds, sprite and text, to build up an immersive pervasive environment with a player in the centre of the game imagery, game domain and real world. The intention of the game was to see how the pervasive game experience could be reflected in the game mechanics and pervasive interaction, while utilising the engine functionality.

year: 2013

title: The “standard story” of anti-Māori talk in Pae Ora (Healthy Futures) Bill submissions

authors: Black, Rose

abstract: AIM: To review some common patterns of race talk in a sample of submissions made to the Pae Ora (Healthy Futures) Bill. This bill proposed a structural reform of the health system in Aotearoa New Zealand to address long-standing health inequities experienced by Māori, the Indigenous peoples, and other priority populations. METHOD: In a sample of 3,000 individual submissions made in late 2021, we found 2,536 explicit references to race. Utilising the “stan-dard story” frame of Pākehā/non-Maori race talk, five longer submissions that inferred that the Pae Ora bill was “racist” were analysed in detail. RESULTS: Many “standard story” race discourses were identified in the Pae Ora submissions. Three derived discourses included in this paper are: Pākehā as norm (monoculturalism or not seeing Pākehā as a culture), equality and the “Treaty” (equality for all to access healthcare), and one people (we are all New Zealanders). Sources such as the Waitangi Tribunal Wai 2575 Hauora report were drawn on to provide alternative discourses. CONCLUSION: Identifying Pākehā standard story discourses enables learning about language patterns systems draw on, and the development of tools and procedures to improve equity for Māori and eliminate institutional racism.

text: The “standard story” of anti-Māori talk in Pae Ora (Healthy Futures) Bill submissions AIM: To review some common patterns of race talk in a sample of submissions made to the Pae Ora (Healthy Futures) Bill. This bill proposed a structural reform of the health system in Aotearoa New Zealand to address long-standing health inequities experienced by Māori, the Indigenous peoples, and other priority populations. METHOD: In a sample of 3,000 individual submissions made in late 2021, we found 2,536 explicit references to race. Utilising the “stan-dard story” frame of Pākehā/non-Maori race talk, five longer submissions that inferred that the Pae Ora bill was “racist” were analysed in detail. RESULTS: Many “standard story” race discourses were identified in the Pae Ora submissions. Three derived discourses included in this paper are: Pākehā as norm (monoculturalism or not seeing Pākehā as a culture), equality and the “Treaty” (equality for all to access healthcare), and one people (we are all New Zealanders). Sources such as the Waitangi Tribunal Wai 2575 Hauora report were drawn on to provide alternative discourses. CONCLUSION: Identifying Pākehā standard story discourses enables learning about language patterns systems draw on, and the development of tools and procedures to improve equity for Māori and eliminate institutional racism.

year: 2023-07-21